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2. Evaluation of As-Received Green Liquor Dregs and Biomass Ash Residues from a Pulp and Paper Industry as Raw Materials for Geopolymers
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Rafael Vidal Eleutério, Lisandro Simão, Priscila Lemes, and Dachamir Hotza
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alkali-activated materials ,biomass fly ash ,compressive strength ,dregs ,geopolymers ,Mineralogy ,QE351-399.2 - Abstract
This study aimed to investigate the impact of as-received biomass fly ashes (BFA) and green liquor dregs obtained from a pulp and paper plant in Brazil as substitutes for metakaolin in geopolymeric formulations. The properties of this type of waste material vary widely between different industrial plants. This study refrains from subjecting the waste materials to any form of pretreatment, taking into account their organic matter and particle size heterogeneity, requiring extensive characterization to evaluate their influence on the compressive strength, apparent open porosity, and water absorption of the geopolymeric samples. The objective was to assess their potential for upcycling purposes as an alternative to energy-intensive materials, such as ordinary Portland cement (OPC) and advanced ceramics. This potential arises from the ability of alkali-activated materials (AAM) to undergo curing at ambient temperatures, coupled with the possibility of compositions primarily derived from waste materials. To improve the sustainability of the products, the amorphous content of the raw material, which is more reactive than crystalline phases, was quantified and used as the base for mixture ratios. This approach aimed to reduce the requirement for alkaline activators, which have significant environmental impacts, while also increasing the waste content in the formulation. The incorporation of waste materials into the geopolymer matrix generally led to a reduction in the compressive strength compared to the benchmark metakaolin sample (19.4 MPa) but did not present a trend. The dregs led to values of 4.1 MPa at 25 wt% and 7.1 MPa at 50 wt%, a behavior that is somewhat counterintuitive, and BFA at 10 wt% presented 5.7 MPa. Nevertheless, the apparent open porosity remained at high levels for all the samples, close to 50%, and the compressive strength of most of them was over the values obtained for the metakaolin-only samples with mixture ratios calculated from the total composition instead of the amorphous composition. The decrease in strength and the increase in porosity were attributed to the specific characteristics of the waste materials, such as their high crystallinity, presence of organic matter, heterogeneous particle composition, and size. Overall, this study provides insight into the variations in geopolymerization based on the bulk and amorphous content of the aluminosilicate sources and how the characteristics of the waste materials influence the geopolymer matrix. It also highlights how calculating mixture ratios based on the amorphous composition improves the possibility of waste valorization through alkali activation. Additionally, it suggests that BFA and dregs might be effectively utilized in applications other than OPC substitution, such as adsorption, filtration, and catalysis.
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- 2023
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3. Fiftieth Rochester Mineralogical Symposium: Contributed Papers in Specimen Mineralogy—Part 1.
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MINERALOGY , *HEAVY minerals , *GEMS & precious stones , *GEOLOGICAL surveys , *ENVIRONMENTAL sciences , *GARNET - Abstract
Many more pseudomorphs are nucleated from the azurite matrix interface than nucleated from the azurite crystal surface. In conclusion, the analysis of these pseudomorph illustrations suggests the following: Azurite can continue to grow on azurite while malachite pseudomorphs are growing within. The four azurite crack surfaces have conchoidal fractures on one surface, complete coverage of new secondary azurite on a second surface, and two vertical surfaces with mixed conchoidal areas and new azurite. The governing reaction for malachite growth is: Two azurites plus one water yields three malachites plus carbon dioxide. [Extracted from the article]
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- 2023
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4. Forty-Ninth Rochester Mineralogical Symposium: Contributed Papers in Specimen Mineralogy—Part 3.
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APATITE , *MINERALOGY , *MINERALS , *ROCK-forming minerals , *SILICATE minerals , *GEMS & precious stones - Abstract
Most of the micromineral inclusions generated by the RMR process in Schickler apatite appear to be REE minerals; an example EDS spectrum of a typical REE inclusion is shown in figure 2. The I T i I O i I T i modules within these minerals can be used to derive many mineral properties by first principles, e.g., habit, cleavage angles, and symmetry/polytypism (fig. 1). Among other minerals, striking red-brown apatite crystals, to 10+ cm, can be found hosted within the dissociated calcite-fluorite carbonatite matrix. However, the diversity of these modular rock-forming minerals results in complexity in terms of the crystal structures and crystal chemistries of this mineral family. [Extracted from the article]
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- 2023
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5. Forty-Ninth Rochester Mineralogical Symposium: Contributed Papers in Specimen Mineralogy—Part 1.
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MINERALOGY , *GEMS & precious stones , *HEAVY minerals , *EARTH sciences , *ENVIRONMENTAL sciences , *RUTILE , *MINERAL dusts - Published
- 2022
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6. Paper of RILEM TC 282-CCL: mineralogical characterization methods for clay resources intended for use as supplementary cementitious material
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Ruben Snellings, Roger Almenares Reyes, Theodore Hanein, Edgardo F. Irassar, Fragkoulis Kanavaris, Matthias Maier, Alastair T. Marsh, Luca Valentini, Franco Zunino, and Adrian Alujas Diaz
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characterisation ,cement ,spectroscopy ,supplementary cementitious materials ,calcined clay ,clay ,Building and Construction ,pozzolanic reactivity ,base-line ,society source clays ,kaolinitic clays ,thermal-analysis ,Mechanics of Materials ,quantitative phase-analysis ,ray-fluorescence spectrometry ,rietveld method ,General Materials Science ,mineralogy ,Civil and Structural Engineering - Abstract
To respond to the rapid introduction and development of calcined clays as supplementary cementitious material (SCM), the toolbox of characterization methods for cementitious materials requires extension to raw clay characterization. Borrowing concepts and methods developed in the field of clay mineralogy, this paper outlines the merits and limits of widely accessible characterization techniques for raw clays intended for use as SCM, when calcined. The paper focuses mainly on the identification and quantification of the raw clay mineral components, as these characteristics have important implications for further material processing and performance. General notes are provided on clay sampling and pre-treatment as well as bulk chemical analysis. The main techniques considered are X-ray diffraction, thermal analysis and infrared spectroscopy. Their application on raw clays is introduced, highlighting clay-specific aspects of sample preparation, data acquisition, and processing. Guidelines and interpretation tables are provided to aid in the analysis of the acquired data, while limitations and potential interferences are identified. Options for remote prospection by infrared spectroscopy are included as well. To illustrate the type of information to be gained and the complementarity of the techniques, two representative raw clays are fully characterised. This paper aims to highlight that mineralogical characterization is a feasible and often necessary step in the study and assessment of raw clays that can deliver a wealth of informative data if carried out appropriately.
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- 2022
7. Forty-Ninth Rochester Mineralogical Symposium: Contributed Papers in Specimen Mineralogy—Part 2.
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MINERALOGY , *PHOSPHATE minerals , *CALCITE crystals , *MINERALS , *SILICATE minerals , *SULFIDE minerals , *ZIRCON - Abstract
The acicular quartz was the first mineral to form, and crystals can be found protruding from quartz of normal morphology that grew around them. This would lead to the change from earlier crystallizing As-bearing sulfide minerals (arsenopyrite) to later-forming arsenide minerals (löllingite) in the core zone as the sulfur anions became depleted. The pegmatite has the highest mineral species count, currently 183 (Falster et al. [2]), in the state of Maine. [Extracted from the article]
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- 2022
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8. Properties and occurrence of clay resources for use as supplementary cementitious materials: a paper of RILEM TC 282-CCL
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Adrian Alujas Diaz, Roger S. Almenares Reyes, Theodore Hanein, Edgardo F. Irassar, Maria Juenger, Fragkoulis Kanavaris, Matthias Maier, Alastair T. Marsh, Tongbo Sui, Karl-Christian Thienel, Luca Valentini, Bin Wang, Franco Zunino, and Ruben Snellings
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Technology ,Engineering, Civil ,MONTMORILLONITE ,smectite ,supplementary cementitious materials ,Materials Science ,POZZOLANIC ACTIVITY ,Clay resources ,THERMAL-STABILITY ,Materials Science, Multidisciplinary ,montmorillonite ,Common clay ,ACTIVATION ,Engineering ,calcined clays ,CALCINED CLAYS ,General Materials Science ,pozzolanic activity ,aipea nomenclature ,Supplementary cementitious materials ,Civil and Structural Engineering ,Science & Technology ,kaolinite ,MINERALOGY ,Building and Construction ,PERFORMANCE ,KAOLINITE ,REACTIVITY ,clay resources ,common clay ,reactivity ,Mechanics of Materials ,Construction & Building Technology ,AIPEA NOMENCLATURE ,activation ,mineralogy ,Smectite ,thermal-stability ,performance - Abstract
The use of clays as resource of supplementary cementitious materials (SCMs) for a new generation of low-carbon cements and concretes is currently the subject of intense research efforts. To this purpose, a large number of clay resources have been explored, characterized and evaluated. This paper introduces the basic knowledge and concepts on clay occurrence and clay mineralogy, before presenting up-to-date knowledge on properties and occurrence of clay resources suitable for use as SCMs. Occurrence, distribution and chemical and mineralogical selection criteria are discussed for kaolinitic clays, which often show superior reactivity and performance. 2:1 clay mineral resources have received somewhat less attention as SCM resources, however recent developments indicate significant potential for calcined impure common clays, and are reviewed. An overview of ubiquitous clay mineral-bearing waste materials also identifies important opportunities for alternative clay sourcing in mining or extraction residues, and dredged or excavated sediments.
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- 2022
9. Forty-Eighth Rochester Mineralogical Symposium: Contributed Papers in Specimen Mineralogy—Part 1.
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MINERALOGY , *MINERALS , *PHOSPHATE minerals , *GEMS & precious stones , *ALKALIC igneous rocks , *BRECCIA , *GOLD ores - Published
- 2021
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10. Improving Students' Mineral and Rock Identification Skills through Service-Learning
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Chaumba, Josphine and Chaumba, Jeff
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This paper reports on a service-learning component introduced in an upper-level undergraduate geology course. Students identified rock types used by a local countertop manufacturing company and made fliers describing their mode of formation. Students then completed a final rock identification exam. To assess the effect of participating in the service-learning on students' rockidentification abilities, an Independent Samples t-test was used to compare scores of students that completed the course to those from previous semesters who did not participate in service-learning. Students who participated in service-learning achieved higher final rock identification exam test scores (M = 91.71, SD = 1.59) in comparison to those who did not take part in any service-learning activity (M = 80.36, SD = 1.88), t (19) = 4.59, p < 0.05. Service-learning projects that involve local geology related industries, thus, can facilitate knowledge sharing between the University and the community.
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- 2022
11. Experimental Study on Pore Structure and Soil-Water Characteristic Curve of Ionic Rare Earth Ore under Seepage
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Yunzhang Rao, Xiaoming Zhang, Zhongquan Gao, Run Xiang, and Laiye Zhang
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ionic rare earth ore ,filter paper method ,soil-water characteristic curve ,nuclear magnetic resonance ,pore structure ,Mineralogy ,QE351-399.2 - Abstract
The ionic rare earth (RE) ore body undergoes particle transport and pore structure change during the leaching process, resulting in "uneven percolation, preferential channel, leaching blind area," and other problems, leading to structural changes in the ore body, low leaching efficiency, and waste of resources. The unsaturated infiltration process is also the key stage that causes these problems. The initial pore structure evolution of the ore body plays a decisive role in the permeability coefficient of the ore body, and the direct influencing factor of the permeability coefficient is the distribution of the pore radius. We carried out research through indoor simulated leaching, the filter paper method for determining matrix suction, and nuclear magnetic resonance (NMR) testing. An ionic rare earth ore soil-water characteristic curve within a large matrix suction range was obtained by the filter paper method. With the increase in volumetric water content, the matrix suction presents a sharp downward trend. When the volumetric water content is less than 20%, this rule is particularly obvious. With the increase in matrix suction, the thickness of the adsorbed water film on the particle surface and pore radius show a decreasing power function trend. Under percolation, the porosity of an ionic rare earth ore sample tends to increase linearly with the increase in volumetric water content during the process from non-saturation to saturation; the porosity of a saturated ore sample after seepage expanded by 17.5 times compared to that of an unsaturated ore sample before seepage. The change rule of the internal microstructure of the ore sample is reflected in the gradual disappearance of micro pores and the gradual formation of small, medium, large, and mega pores, which shows a gradual increase trend. In the pore radius distribution, the more large and medium pores, the larger the permeability coefficient; the more micro and small pores, the smaller the permeability coefficient. For some ore bodies with poor permeability, the ore body is infiltrated with clear water under small water pressure before leaching with a leaching solution, which can improve the permeability of the ore body, effectively improve the efficiency of rare earth leaching, and increase the economic benefits.
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- 2023
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12. Forty-Eighth Rochester Mineralogical Symposium: Contributed Papers in Specimen Mineralogy—Part 3.
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MINERALOGY , *CALCITE crystals , *GEMS & precious stones , *SPODUMENE , *FLUORAPATITE - Abstract
One spodumene crystal exceeded 11 meters in length, and crystals in excess of 2 meters in length are common. It is spodumene-rich with more than 50 percent spodumene in some of the upper portions of the pegmatite. These spodumene and montebrasite crystals are comparable in size to the famous crystals from the Etta and Hugo pegmatites in South Dakota, where 14-meter spodumene crystals and 7-meter amblygonite (likely montebrasite) occur (Rickwood [1]). [Extracted from the article]
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- 2022
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13. Forty-Eighth Rochester Mineralogical Symposium: Contributed Papers in Specimen Mineralogy—Part 2.
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MINERALOGY , *EARTH sciences , *ENVIRONMENTAL sciences , *COPPER phthalocyanine , *MICROSCOPY - Published
- 2022
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14. Mineralogy of Zinc and Lead Metallurgical Slags in Terms of Their Impact on the Environment: A Review.
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Nowińska, Katarzyna and Kokowska-Pawłowska, Magdalena
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LEAD ,HEAVY metals ,LEAD sulfide ,ZINC sulfide ,HAZARDOUS wastes ,SPHALERITE - Abstract
This paper presents the results of a study of the mineralogical and chemical composition of zinc and lead metallurgical slags. These slags contain numerous elements, including toxic metals, which form conglomerates or multiphase intergrowths. The phase composition of slags is one of the main factors that determine their behaviour in weathering environments, that is, their ability to release metals when exposed to atmospheric factors. In this paper, the release of elements from slags and their mobility in a hypergenic environment is determined based on the results of leachability tests and on geochemical modelling, thus assessing the environmental impact of landfilled slags. The elements released from slags in the largest quantities are zinc and lead. Zn is leached out over a long period of time. It was found that after 12 years, the concentration of Zn in the eluate exceeds by 40 times the permissible value of 200 mg/kg for hazardous waste. The degree of leaching of lead from slags as a function of time (after 12 years), despite its significant solubility in water, is much lower than the degree of leaching of zinc. The most mobile phase components of slags in the studied hypergenic environment are the lead phases (anglesite and galena) and, to a lesser extent, the zinc phases (sphalerite and willemite). Anglesite and galena in almost the entire Eh-pH range, along with admixtures of elements, decompose into ionic forms: PbCl
4 2− , Pb2+ , and PbOH+ . Sphalerite in the soil and water environment (oxidizing and acidic conditions) will decompose into the mobile ionic form Zn2+ . Willemite, which is resistant to weathering, will undergo similar decomposition. It can therefore be assumed that the carriers of toxic metals are primarily lead sulphides and sulphates, zinc sulphides, and, less frequently, zinc, lead, and iron oxides. [ABSTRACT FROM AUTHOR]- Published
- 2024
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15. Magmatism in Kamchatka and the Kurile Islands.
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MAGMATISM ,ISLANDS ,PETROLOGY ,ULTRABASIC rocks ,MINERALOGY ,GEOLOGY - Abstract
It is senseless to study modern volcanism in Kamchatka and therewith ignore the Kurile Islands, which are a natural continuation of Kamchatka. The authors compare the petrography, mineralogy, and geochemistry of the lavas with those of the products of summit eruptions and demonstrate that all the rocks are similar in phenocryst associations and petrography. The complex geological history of Kamchatka and the diversity of its active modern volcanism make it an ideal "natural laboratory" for studying the most topical problems of petrology and geology. [Extracted from the article]
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- 2023
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16. Lime Stabilization of Tropical Soil for Resilient Pavements: Mechanical, Microscopic, and Mineralogical Characteristics.
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Diniz, Bruna Calabria, Fedrigo, William, Kleinert, Thaís Radünz, Batista, Giovanni dos Santos, Núñez, Washington Peres, Correa, Bethania Machado, and Brito, Lélio Antônio Teixeira
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SOIL stabilization ,SCANNING electron microscopy ,CALCIUM hydroxide ,TENSILE tests ,X-ray diffraction - Abstract
Lime stabilization is a sustainable technique due to its use of local materials, increased durability, reduced maintenance, and improved resistance to water action. This paper examines the impact of lime stabilization on the mechanical, microscopic, and mineralogical properties of a tropical soil. Two types of lime, calcitic and dolomitic, were tested at 3% and 5% by weight. Compressive, indirect tensile and flexural test results and statistical analysis revealed that calcitic lime mixtures had higher strength and stiffness, whereas dolomitic lime mixtures exhibited greater deformability with higher tensile strain at break. Scanning electron microscopy indicated that the soil's porous matrix closed within 7 days for both lime types due to flocculation, with increased matrix interlocking over time. The calcitic lime mixture developed a more closed matrix compared to the dolomitic lime, which showed weaker cementing. X-ray diffraction analysis indicated higher consumption of clay minerals and a notable reduction in calcium hydroxide peaks in the lime-treated soils. The study concludes that calcitic lime provides better pavement performance for stabilizing the soil, enhancing its engineering properties while also being sustainable by reducing the need for raw material extraction and improving resilience to climate-related issues such as floods. [ABSTRACT FROM AUTHOR]
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- 2024
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17. Composition of renders and plasters of award-winning buildings in Lisbon (Portugal): A contribution to the knowledge of binders used in the 20th Century.
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Almeida, Luís, Silva, A. Santos, Veiga, Rosário, and Mirão, José
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PORTLAND cement ,X-ray diffraction ,ANALYTICAL chemistry ,THERMAL analysis ,MICROSCOPY - Abstract
This paper reports on the study of renders and plasters from 20th-century award-winning buildings in Lisbon (Portugal) with the Valmor Prize for Architecture. The mortars have been investigated through XRD, optical and electronic microscopy (SEM-EDS), thermal analysis (TGA/DTA), wet chemical analyses and AAS. The results reveal that the use of air lime lasted until the 1940s. It also highlights the beginning of using of Portland cement in mortars in the 1930s, mixed with air-lime, and the abandonment of mortar formulations solely based on air lime. This study highlights the use of finishing lime-gypsum-based mortars until the 1940s and different types of Portland cement from the 1940s onwards. Portland cement was the main binder for the analysed stone-imitating mortars from 1940s to 1970s. Finally, salt contamination was occasionally found in mortars, which generally reveal a good state of conservation. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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18. The Role of Fabric, Stress History, Mineralogy, and Particle Morphology on the Triaxial Behavior of Nontextbook Geomaterials.
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Carvalho, João Vítor de Azambuja, Wagner, Alexia Cindy, Scheuermann Filho, Hugo Carlos, and Consoli, Nilo Cesar
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MINERALOGY ,SOIL mechanics ,IRON ores ,PARTICULATE matter ,IRON oxides ,COMPLEX matrices ,METAL tailings - Abstract
Soil mechanics traditionally have focused on studying pure clays and clean sands. However, natural soils and other geomaterials usually do not fall into these two classes. Most geomaterials are a complex matrix of fines and coarser particles, with distinct shapes and mineralogy interacting. This paper studied iron ore tailings over a broad range of pressures and stress histories to investigate the mechanical behavior of this nontextbook geomaterial. A thorough experimental program was conducted, and aspects of the stress–strain response, yielding, hardening, and critical state were evaluated. The state boundary surface of iron ore tailings also was investigated. The results demonstrated that the stress history of tailings affects the tailings' behavior only at elevated stress levels. The existence of particles with distinct mineralogy in the iron ore tailings (mainly iron oxide and quartz) could have induced different breakage patterns, with an evolving particle morphology being the dominant mechanism up to the pressures achieved. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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19. Assessment of the Radioactivity, Metals Content and Mineralogy of Granodiorite from Calabria, Southern Italy: A Case Study.
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Dattola, Luigi, Belvedere, Alberto, D'Agostino, Maurizio, Faggio, Giuliana, Majolino, Domenico, Marguccio, Santina, Messina, Giacomo, Messina, Maurizio, Mottese, Antonio Francesco, Paladini, Giuseppe, Venuti, Valentina, and Caridi, Francesco
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INDUCTIVELY coupled plasma mass spectrometry ,GAMMA ray spectrometry ,RADIOLOGICAL health risk ,NATURAL radioactivity ,IONIZATION chambers ,RADIOISOTOPES ,RADIOACTIVITY - Abstract
In this paper, an assessment of the natural radioactivity level, radon exhalation, metal contamination, and mineralogy of a granodiorite rock sample from Stilo, in the Calabria region, Southern Italy is presented as a case study. This rock was employed as a building material in the area under study. The specific activity of
226 Ra,232 Th and40 K natural radioisotopes was assessed through high-purity germanium (HPGe) gamma-ray spectrometry. Then, several indices such as the absorbed gamma dose rate (D), the annual effective dose equivalent (AEDE), the activity concentration index (ACI) and the alpha index (Iα ), were quantified to determine any potential radiological health risk related to radiation exposure from the analyzed rock. Furthermore, E-PERM electret ion chambers and inductively coupled plasma mass spectrometry (ICP-MS) measurements were carried out to properly quantify the radon exhalation rate and any possible metal pollution, respectively. In particular, to further address metal pollution factors, the geo-accumulation index (Igeo ) was calculated to properly address the toxicity levels of the ecosystem originating from the detected metals. Finally, with the aim of successfully discriminating the provenance of such naturally occurring radionuclides, a combined approach involving X-ray diffraction (XRD) and µ-Raman spectroscopy was employed for the identification of the main radioisotope-bearing minerals characterizing the investigated granodiorite. The results achieved in this case study can be taken as the basis for further inquiries into background levels of radioactivity and chemical contamination in natural stone employed as building materials. [ABSTRACT FROM AUTHOR]- Published
- 2024
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20. Reactive transport modeling constraints on the complex genesis of a lacustrine dolomite reservoir: A case from the Eocene Qaidam Basin, China.
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Ying Xiong, Bo Liu, Xiu-Cheng Tan, Zheng-Meng Hou, Jia-Shun Luo, Ya-Chen Xie, Kai-Bo Shi, and Kun-Yu Wu
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EVAPORITES ,MINERALOGY ,EOCENE Epoch ,PARAGENESIS ,SEDIMENTATION & deposition ,DOLOMITE - Abstract
Reactive transport modeling (RTM) is an emerging method used to address geological issues in diagenesis research. However, the extrapolation of RTM results to practical reservoir prediction is not sufficiently understood. This paper presents a case study of the Eocene Qaidam Basin that combines RTM results with petrological and mineralogical evidence. The results show that the Eocene Xiaganchaigou Formation is characterized by mixed siliciclastic-carbonate-evaporite sedimentation in a semiclosed saline lacustrine environment. Periodic evaporation and salinization processes during the syngeneticpenecontemporaneous stage gave rise to the replacive genesis of dolomites and the cyclic enrichment of dolomite in the middle-upper parts of the meter-scale depositional sequences. The successive change in mineral paragenesis from terrigenous clastics to carbonates to evaporites was reconstructed using RTM simulations. Parametric uncertainty analyses further suggest that the evaporation intensity (brine salinity) and particle size of sediments (reactive surface area) were important rate-determining factors in the dolomitization, as shown by the relatively higher reaction rates under conditions of higher brine salinity and fine-grained sediments. Combining the simulation results with measured mineralogical and reservoir physical property data indicates that the preservation of original intergranular pores and the generation of porosity via replacive dolomitization were the major formation mechanisms of the distinctive lacustrine dolomite reservoirs (widespread submicron intercrystalline micropores) in the Eocene Qaidam Basin. The results confirm that RTM can be effectively used in geological studies, can provide a better general understanding of the dolomitizing fluid-rock interactions, and can shed light on the spatiotemporal evolution of mineralogy and porosity during dolomitization and the formation of lacustrine dolomite reservoirs. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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21. Study on Column Leaching Behavior of Low-Grade High Calcium and Magnesium Copper Ore.
- Author
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Xu, Jingyuan, Qin, Shuchen, Zheng, Chaozhen, Sun, Honghong, Yang, Baojun, Liu, Sanping, Qiu, Guanzhou, Northwood, Derek O., Waters, Kristian E., and Ma, Hao
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DIFFUSION control ,CHEMICAL reactions ,COPPER ores ,SULFURIC acid ,MINERALOGY ,LEACHING - Abstract
This paper studies the process mineralogy, mechanism, and kinetics of column leaching behavior of low-grade high-calcium–magnesium copper ore. The effect of sulfuric acid concentration, leach solution spraying intensity, and material particle size on column leaching kinetics is discussed. The kinetic analysis of column leaching of copper indicates that sulfuric acid concentration has a significant impact. As sulfuric acid concentration increases, the limiting step of reaction shifts from chemical reaction control to a combination of chemical reaction and diffusion mixing control. Spraying intensity also affects copper column leaching; increasing intensity shifts the limiting step from diffusion control to mixing control, thereby mitigating the effects of diffusion control. Regarding other elements, it is found that iron leaching is primarily controlled by chemical reaction, while calcium leaching is mainly controlled by chemical reaction. As sulfuric acid concentration increases from 10 g/L to 20 g/L, the limiting step for calcium leaching shifts from chemical reaction control to chemical reaction and diffusion-mixing control. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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22. The Effect of Soil Mineralogy and Particle Breakage on the Impulse Generated from Shallow Buried Charges.
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Lodge, Tommy, Clarke, Sam, Waddoups, Ross, Rigby, Sam, Gant, Matt, and Elgy, Ian
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SOIL mineralogy ,SOIL particles ,BLAST effect ,MINERALOGY ,QUARTZ - Abstract
Featured Application: Protection of vehicles and personnel from the devastating effects of landmines, shallow buried IEDs and explosive remnants of war remains a high priority in afflicted conflict and post-conflict areas. With most testing available in the literature having been conducted with quartz-based soils, this paper presents a comparative study on carbonate-based soils, as found in many regions across the world, providing data to allow the risk posed to vehicles and personnel to be assessed. Historically, most testing with shallow buried charges has focussed on soils which are predominantly quartz (silica)-based. Particle size, moisture content and density have previously been investigated to ascertain their importance, along with other geotechnical parameters, in governing the magnitude of an impulsive output. This has shown that, in order of importance, moisture content, density and particle size drive the total impulse imparted. The work in this paper presents the results of blast testing carried out with carbonate sands to investigate the difference that particle mineralogy (and hence, propensity for breakage) has on both the localised loading and the total impulse using an array of 17 Hopkinson pressure bars known as the Characterisation of Blast Loading (CoBL) apparatus. Carbonate sands are thought to have more friable particles due to their plate-like morphology, as opposed to the rounded morphology of quartz-based sands. Testing was conducted with low moisture content samples and compared with the well-established Leighton Buzzard uniform sand to isolate the effect of particle mineralogy/morphology on the loadings measured. The results show that, despite attaining a 23% lower bulk density, carbonate soils deliver almost identical total impulses (0.7–3.0% higher) when compared with quartz soils for nominally identical moisture contents. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
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23. New information on late antique to early Islamic ceramic production and distribution in the Gulf. Petrography of samples from Siraf, Bushehr, and Fulayj.
- Author
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LÓPEZ, JOSÉ C. CARVAJAL, PRIESTMAN, SETH M. N., and GEORGAKOPOULOU, MYRTO
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PETROLOGY ,CERAMICS ,MICROSCOPY ,POTTERY ,MINERALOGY ,TOMBS - Abstract
In this paper a new petrographic study of ceramics from the late antique to the early Islamic period in the Gulf is presented. The paper considers samples from Siraf (Iran), excavated by David Whitehouse (from the Ashmolean Museum, Oxford, UK), samples from the Iranian coast (recovered by Andrew Williamson, Durham University, UK), and samples from Fulayj, Oman (excavated by a team co-directed by Seth Priestman, Nasser Al-Jahwari, Eve MacDonald, and Derek Kennet). The technique of analysis is petrography, which offers compositional (mineralogy and petrology) and textural information (distribution and arrangement of inclusions). This technique can be used to interpret the technological procedures involved in the manufacturing of ceramics and to characterize products from particular areas, thus helping to clarify trends of distribution of wares across time. The samples of these collections have been classified according to Priestman's Indian Ocean Pottery Classification (IOPC; Priestman 2021), providing an important link between macroscopic and microscopic analyses. The results are also compared with samples previously analysed from Murwab and the Old Doha excavations, providing an overview of the production technology and exchange of ceramics in the early Islamic Gulf over the longue durée. [ABSTRACT FROM AUTHOR]
- Published
- 2023
24. Assessment of carbonate rocks for engineering applications considering mineralogical, geochemical and geotechnical attributes
- Author
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Okewale, Ismail Adeniyi, Grobler, Hendrik, and Mulaba-Bafubiandi, Antoine F.
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- 2024
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25. Microstructural differences between naturally-deposited and laboratory beach sands
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Nicholas Sitar, Michael Manga, Amy Ferrick, and Vanshan Wright
- Subjects
Original Paper ,Pluviation ,Contact geometry ,Mechanical Engineering ,Fluids & Plasmas ,General Physics and Astronomy ,Mineralogy ,Coordination number ,Chemical Engineering ,Microstructure ,Civil Engineering ,Sedimentary depositional environment ,Computed microtomography ,Mechanics of Materials ,General Materials Science ,Grain orientation ,Geology ,X-ray computed microtomography - Abstract
The orientation of, and contacts between, grains of sand reflect the processes that deposit the sands. Grain orientation and contact geometry also influence mechanical properties. Quantifying and understanding sand microstructure thus provide an opportunity to understand depositional processes better and connect microstructure and macroscopic properties. Using x-ray computed microtomography, we compare the microstructure of naturally-deposited beach sands and laboratory sands created by air pluviation in which samples are formed by raining sand grains into a container. We find that naturally-deposited sands have a narrower distribution of coordination number (i.e., the number of grains in contact) and a broader distribution of grain orientations than pluviated sands. The naturally-deposited sand grains orient inclined to the horizontal, and the pluviated sand grains orient horizontally. We explain the microstructural differences between the two different depositional methods by flowing water at beaches that re-positions and reorients grains initially deposited in unstable grain configurations.
- Published
- 2022
26. The use of particle size distribution integrated with consistency limits for experimentally simulating fine-grained sedimentary units
- Author
-
Zainab A. Al-Humaidan, Lindsey S. Bryson, and Wisam Razzaq Muttashar
- Subjects
geography ,Original Paper ,geography.geographical_feature_category ,Engineering geology ,Bay mud ,Mineralogy ,Sediment ,Mixture procedure ,Mesopotamian plain ,Basrah ,Particle size distribution ,Southern Iraq ,Sedimentary depositional environment ,Particle-size distribution ,General Earth and Planetary Sciences ,Sedimentary rock ,Sedimentology ,Sedimentary environments ,Levee ,Geology ,Simulation ,General Environmental Science - Abstract
The current study hypothesizes that reproducing sediment units that might belong to areas difficult to reach, sample, and attest is experimentally possible. The research aims to employ available sediment samples named source soils that can easily approach and sample to mix, simulate, and produce the (non-available) sedimentary units named Target Sediment Units (TSU). The particle size distribution (PSD) percentages are essentially used in the mixture procedure to construct the non-available (target) units (TSU). Several sedimentary units were targeted, designed, and simulated; They include marsh, bay mud, and natural levee sediment units selected from the eastern Basrah side at the lower Mesopotamian plain, southern Iraq. The matching between particle size distribution (PSD) curves of simulated sediment units (SSU) and target sediment unit (TSU) was verified by applying a developed slope proximity ratio. For the three tested sediment units (marsh, buy mud, and natural levee), the ratios of slope proximity were 1.0, 0.93, and 0.99, respectively, which are well matched. For the mineralogy, the consistency limits were used as a proxy. The Casagrande plasticity chart was modified to reveal two empirical functions linking the plasticity indices to the clay mineral groups. The two predictions are reliable means to proxy the mineralogy of the fine-grained sediments. Reconstructing procedure allows the non-available sediment samples to be practically presented and it better characterizes the sediment for forensic geoscience applications; for instance, engineering geology and sedimentology applications concerning with studies of the physical and mechanical behaviors of sediments and the depositional conditions interpretations, respectively.
- Published
- 2021
27. Lithophysical characteristics of productive strata of cupriferous sandstone within Zhezkazgan ore district in the Central Kazakhstan.
- Author
-
Istekova, Sara, Aidarbekov, Zhandos, Togizov, Kuanysh, Saurykov, Zhanibek, Sirazhev, Arman, Tolybayeva, Dina, and Temirkhanova, Raushan
- Subjects
SANDSTONE ,PETROLOGY ,MINERALOGY ,MINERAL industries ,SULFIDE minerals - Abstract
Purpose. The paper concerns additional geological appraisal and identification of extra localization criteria of cupriferous mineralization of a stratiform type. The research is intended to define physical and geological factors influencing sandstone distribution within the north-end of Zhezkazgan synclinal in the Central Kazakhstan. Methods. A complex analysis of geological and mineralogical, geophysical, and geochemical data was carried out relying upon the information obtained from deep-hole wells. Modern methods to process and interpret the field data were applied. The analysis involved lithological dismemberment of the productive Taskuduk suite as well as determination of sulfide mineralization zone boundaries. Findings. The research has shown that the productive levels reach down to 1500-m depth. The data interpretation has helped specify the geological structure and develop a model of ore-promising bodies of cupriferous sandstones at great depth. The applied complex data analysis has increased potential to prospect new loci of productive cupriferous sandstone deposits of Zhezkazgan type. Originality. The research has contributed significantly to understanding of the physical and geological factors influencing the copper ore distribution in deep layers. New physical and geological criteria, determining deep copper mineralization localization, have been identified which were not considered by earlier similar studies. Practical implications. The obtained new data as well as the developed methods are important while deep drilling planning and implementing to identify promising copper mineralization sites. The findings may be used to optimize exploration within the north-end of Zhezkazgan synclinal, and other districts having analogous geological conditions. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
28. Identification of mineralogical ore varieties using ultrasonic measurement results.
- Author
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Morkun, Volodymyr, Morkun, Natalia, Fischerauer, Gerhard, Tron, Vitalii, Haponenko, Alona, and Bobrov, Yevhen
- Subjects
MINERALOGY ,ELASTIC waves ,LIGHT propagation ,MINERAL industries ,IRON ores - Abstract
Purpose. To improve the measurement and information base of ultrasonic measurements rock characteristics to assess their mineralogical varieties. It is proposed to use a combination of measurement results of the acoustic quality factor of the test sample in relation to longitudinal and transverse ultrasonic waves, as well as the characteristic coefficient based on the dispersion and the average amplitude value of the received signal, for fuzzy identification of mineralogical and technological varieties of iron ore. Methods. As elastic waves propagate through the rock mass, they undergo attenuation due to absorption and dissipation of ultrasonic signal energy. The degree of attenuation, as well as the wave propagation velocity, is dependent on the physical mechanical and chemical-mineralogical properties of the medium through which they travel. In this paper, we analyze a rock characterized by a complex structure comprising ore inclusions and surrounding matrix, each of which differs in its physical mechanical and chemical-mineralogical properties. In particular, in iron ore samples, the distribution of mineral grains and aggregates exhibits significant heterogeneity in terms of both amount and size. Findings. An iterative method of fuzzy identification of mineralogical-technological iron ore varieties, based on the analysis of their properties in vector space of features, allows, by minimizing the sums of weighted distances between the analyzed and reference values of ultrasonic measurement results, to attribute them with a certain degree of belonging to the main technological types of ores mined at the deposit, and define them as magnetite quartzite with a confidence probability of 0.93. Originality. As an information base for identification of mineralogical iron ore varieties, the results of measuring the velocity and attenuation of longitudinal and transverse ultrasonic waves of appropriate frequency are used, on the basis of which the acoustic quality factor of the rock sample is calculated, as well as the characteristic parameter S, which is determined by the dispersion and average values of the received ultrasonic signal intensity, which has traveled a certain distance in the studied environment. Practical implications. The results of tests and practical approbation of the method for identifying mineralogical iron ore varieties based on the data of ultrasonic well logging testify to its high efficiency, which allows recommending the developed scientific-technical solutions for wide industrial application at mining enterprises. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
29. Numerical Investigation of the Applicability of Preferential Grade Deportment by Size.
- Author
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Baizhiyen, Nazym, Dowd, Peter, Xu, Chaoshui, and Lewis, David
- Subjects
DISCRETE element method ,MINERAL properties ,GRANULAR materials ,CRACK propagation (Fracture mechanics) ,MINERALOGY - Abstract
The effective separation of ore is based on two fundamental processes: liberation and separability. Liberation involves the reduction of size, yielding smaller particles with enhanced compositional homogeneity. Understanding liberation requires an understanding of rock breakage, as it impacts mineral liberation and helps identify ores suitable for pre-concentration. Non-random breakage, influenced by textural and mineral properties, introduces heterogeneity in mineral distribution across size fractions. Physical attributes, including ore and gangue mineralogy and texture, influence fractionation tendencies during breakage. Notably, the presence of mineralization in veins substantially assists early-stage liberation in mineral processing. The aim of this study is to develop a methodology that allows the prediction of natural fractionation tendencies based on geological, mineralogical, and textural data using Discrete Element Method (DEM) modeling. DEM simulations provide insights into granular material behavior, capturing phenomena such as crack initiation and propagation. The use of DEM, particularly with models such as the Flat Joint Model (FJM), enhances our understanding of rock damage mechanisms. In this paper, DEM is used to predict preferential grade by size deportment, and a numerical model is developed to reflect grade distributions across size fractions. A fragmentation analysis is conducted after rock breakage simulations using DEM to analyze the fragment sizes and grades and calculate the Response Rankings of synthetic specimens. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
30. Dos Gabinetes de Ensino a Museu: a trajetória da coleção de mineralogia da Escola de Minas de Ouro Preto.
- Author
-
Ribeiro Jotta, Carlos Augusto
- Subjects
ARCHIVES ,MINING engineering ,MAP collections ,TRAINING of engineers ,MINERALOGY - Abstract
Copyright of Museologia e Patrimônio is the property of Museologia e Patrimonio and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2024
- Full Text
- View/download PDF
31. Peculiar Features of Lime-Treated Pyroclastic Soils through a Multi-Scale Experimental Investigation.
- Author
-
Cecconi, Manuela and Russo, Giacomo
- Subjects
CLAY soils ,SOILS ,POZZOLANIC reaction ,WASTE recycling ,CLAY minerals - Abstract
Soil-improvement techniques with binders are used in several geotechnical engineering applications as a sustainable solution for the reuse of waste soils. Due to their inherent complexity and their mechanical behaviour, pyroclastic soils are generally considered waste geomaterials in their natural state. Lime treatment of pyroclastic soils can be considered a viable solution for their reuse in geotechnical applications. In this paper, some peculiar features of the chemo-physical evolution and mechanical behaviour of lime-treated pyroclastic soils are evidenced through a multi-scale experimental investigation. While, for clayey soils, the fine fraction is mainly responsible for ion exchange and pozzolanic reactions induced by lime, for pyroclastic soils, pozzolanic reactions are dominant processes due to the low quantity of clay minerals along with the abundance of aluminates and silicates as the main constituents of their amorphous phase. The link between the phenomena detected at the microscale level, the mineralogical composition, and the macroscopic behaviour of two lime treated pyroclastic soils of different origin is explored through a multiscale approach. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
32. Study on Mechanisms for Improving Quality and Whiteness of Phosphogypsum Based on Process Mineralogy Analysis.
- Author
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Dong, Wanqiang, Chi, Ru'an, Guo, Wanxin, Deng, Xiangyi, Chen, Zhuo, and Chen, Haodong
- Subjects
MINERALOGY ,PHOSPHOGYPSUM ,GYPSUM ,GIBBSITE ,X-ray diffraction ,OPTICAL microscopes - Abstract
Because of its low whiteness, complex composition, radioactivity and high impurity percentage, the usage of phosphogypsum (PG) resources is limited. A theoretical foundation for upgrading and bleaching PG can be obtained by researching the presence and status of impurities in the material and its symbiotic connection with gypsum. This paper makes use of an automatic mineral phase analyzer, optical microscope, XRF, XRD and SEM-EDS. After analyzing the chemical makeup of PG, phase composition and particle size composition, the distribution law and symbiotic interaction between impurities and gypsum in various particle sizes were discovered. Using a flotation test, the process mineralogy analysis results were confirmed. According to the XRF and XRD study results, the primary impurity elements in PG are Si, P and F. Si is more abundant in PG that is between +850 μm and −37.5 μm in size. The concentrations of gypsum and quartz in PG are 82.59% and 8.73%, respectively, according to the results of XRD and process mineralogy. The monomer dissociation degree of the gypsum mineral phase is as high as 90.47%. Gibbsite and pyrite are the primary causes of the low whiteness of PG and are clearly related to the quartz mineral phase. The coupling process of "flotation + pickling" produced purified PG with a purity of 95.35%, whiteness of 70.76% and SiO
2 content of 2.73%. The quality met the first-class index standards of PG in GB/T23456-2018. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
33. Twentieth-century Bena iron production in the Njombe district of Tanzania.
- Author
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Lyaya, Edwinus Chrisantus
- Subjects
IRON ores ,GEOCHEMISTRY - Abstract
Copyright of Azania: Archaeological Research in Africa is the property of Routledge and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2022
- Full Text
- View/download PDF
34. Advances in Geospatial Technology in Mining and Earth Sciences : Selected Papers of the 2nd International Conference on Geo-spatial Technologies and Earth Resources 2022
- Author
-
Long Quoc Nguyen, Luyen Khac Bui, Xuan-Nam Bui, Hai Thanh Tran, Long Quoc Nguyen, Luyen Khac Bui, Xuan-Nam Bui, and Hai Thanh Tran
- Subjects
- Earth sciences, Geography, Mining engineering, Underground construction, Geographic information systems, Mineralogy, Geology
- Abstract
This book composes the proceedings of the international conference on Geo-Spatial Technologies and Earth Resources (GTER 2022) which was co-organized by Hanoi University of Mining and Geology and the International Society for Mine Surveying (ISM) held at Hanoi city on October 13–14, 2022.GTER 2022 is technically co-sponsored by Vietnam Mining Science and Technology Association (VMST), Vietnam Association of Geodesy, Cartography and Remote Sensing (VGCR), Vietnam National Coal-Mineral Industries Holding Corporation Limited (VINACOMIN), and the Dong Bac Corporation (NECO).GTER 2022 aims to bring together experts, researchers, engineers, and policymakers to discuss and exchange their knowledge and experiences in recent geospatial technologies, advances in mining and earth sciences.
- Published
- 2023
35. Mapping Geothermal Indicator Minerals Using Fusion of Target Detection Algorithms.
- Author
-
Cavur, Mahmut, Yu, Yu-Ting, Demir, Ebubekir, and Duzgun, Sebnem
- Subjects
ASTER (Advanced spaceborne thermal emission & reflection radiometer) ,MINERALS ,REMOTE-sensing images ,ALGORITHMS ,KAOLINITE ,MINERALOGY - Abstract
Mineral mapping from satellite images provides valuable insights into subsurface mineral alteration for geothermal exploration. In previous studies, eight fundamental algorithms were used for mineral mapping utilizing USGS spectra, a collection of reflectance spectra containing samples of minerals, rocks, and soils created by the USGS. We used an ASD FieldSpec 4 Hi-RES NG portable spectrometer to collect spectra for analyzing ASTER images of the Coso Geothermal Field. Then, we established the ground-truth information and the spectral library by analyzing 97 samples. Samples collected from the field were analyzed using the CSIRO TSG (The Spectral Geologist of the Commonwealth Scientific and Industrial Research Organization). Based on the mineralogy study, multiple high-purity spectra of geothermal alteration minerals were selected from collected data, including alunite, chalcedony, hematite, kaolinite, and opal. Eight mineral spectral target detection algorithms were applied to the preprocessed satellite data with a proposed local spectral library. We measured the highest overall accuracy of 87% for alunite, 95% for opal, 83% for chalcedony, 60% for hematite, and 96% for kaolinite out of these eight algorithms. Three, four, five, and eight algorithms were fused to extract mineral alteration with the obtained target detection results. The results prove that the fusion of algorithms gives better results than using individual ones. In conclusion, this paper discusses the significance of evaluating different mapping algorithms. It proposes a robust fusion approach to extract mineral maps as an indicator for geothermal exploration. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
36. 87 Sr/ 86 Sr Isotope Ratio as a Tool in Archaeological Investigation: Limits and Risks.
- Author
-
Rossi, Mattia, Iacumin, Paola, and Venturelli, Gianpiero
- Subjects
STRONTIUM isotopes ,GEOCHEMISTRY ,ZOOARCHAEOLOGY ,ISOTOPES ,MINERALOGY - Abstract
During the last forty years, the use of strontium isotopes in archaeology and biogeochemical research has spread widely. These isotopes, alone or in combination with others, can contribute to trace past and present environmental conditions. However, the interpretation of the isotopic values of strontium is not always simple and requires good knowledge of geochemistry and geology. This short paper on the use of strontium isotopes is aimed at those who use this tool (archaeologists, but not only) but who do not have a thorough knowledge of mineralogy, geology, and geochemistry necessary for a good understanding of natural processes involving these isotopes. We report basic knowledge and suggestions for the correct use of these isotopes. The isotopic characteristics of bio-assimilable strontium depend not so much on the isotopic characteristics of the bulk rock as, rather, on those of its more soluble minerals. Before studying human, animal and plant remains, the state of conservation and any conditions of isotopic pollution should be carefully checked. Samples should be collected according to random sampling rules. The data should be treated by a statistical approach. To make comparisons between different areas, it should be borne in mind that the study of current soils can be misleading since the mineralogical modification of soil over time can be very rapid. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
37. Critical state analysis of two compacted filtered iron ore tailings with different gradings and mineralogy at different stages of treatment.
- Author
-
Consoli, Nilo Cesar, Silva, João Paulo Sousa, Wagner, Alexia Cindy, Carvalho, João Vítor de Azambuja, Baudet, Beatrice Anne, Coop, Matthew Richard, Scheuermann Filho, Hugo Carlos, Carvalho, Inácio, de Sousa, Gustavo Marçal, and Cacciari, Pedro Pazzoto
- Subjects
IRON ores ,MINERALOGY ,SOIL mechanics ,CRITICAL analysis ,AEROSPACE planes ,IRON mining ,COIN grading - Abstract
Slurry tailings storage in large impoundments has been largely used worldwide for a long time, as their cost is very competitive. However, recent disasters have brought to light the need to better comprehend the mechanics of the materials stored and to search for disposal alternatives to overcome the drawbacks. One possibility is the filtered tailings disposal (dry stacking) which requires a better understanding of the material's response in a dewatered (through filtration) and compacted condition. This paper compares two tailings from the same beneficiation (treatment) plant with different gradings and mineralogy, related to the beneficial processes they undergo. A series of triaxial tests comprising isotropic compression without shearing specimens, as well as isotropic compression followed by drained (CID) and undrained (CIU) shearing, and K-compression followed by undrained (CKU) shearing specimens were conducted over a range of confining pressures and initial compaction degrees. The experimental program allowed the evaluation of convergence for normal compression lines (NCLs) and the analysis under the light of critical state soil mechanics for the stress–strain response of the tested materials. The research outcomes show that changes in iron ore tailings gradings due to different production processes and the use of different compaction degrees had an influence on its behavior (compression and shearing) at lower stress levels, while at higher stresses levels, this difference is erased and there is a convergence for unique and parallels NCL and CSL on ν–ln p′ plane with a spacing of 2.71. On the p′–q plane both tailings showed a unique and similar CSL. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
38. Aptian Li-F Granites of the Northern Verkhoyansk–Kolyma Orogenic Belt, Eastern Russia: Composition, Genesis, and Ore Potential.
- Author
-
Trunilina, Vera A. and Prokopiev, Andrei V.
- Subjects
GRANITE ,ORE deposits ,NONFERROUS metals ,ORES ,OROGENIC belts ,FLUID flow ,GEOCHEMISTRY - Abstract
This paper reports the results from an investigation on the geochemistry and petrogenesis of the Aptian Li-F granites from the Omchikandya, Burgali, and Arga Ynnakh Khaya ore fields in the northern Verkhoyansk–Kolyma orogenic belt in eastern Russia. Li-F microcline–albite granites intrude the Late Jurassic to Early Cretaceous syn-collisional granitoids. According to their geochemical composition, they are close to A-type granites and can be subdivided into low-P and high-P varieties, differing in their geochemistry and genesis. The low-P microcline–albite granites (Omchikandya massif) intrude syn-collisional biotite granites. It is assumed that the formation of their parent melt occurred at deep levels in the same magma chamber that produced biotite granites. The high-P granites (Verkhne–Burgali ethmolith and Kester harpolith) are supposed to have been derived from melts originated from a high-grade metamorphosed lower crustal protolith under the influence of deep-seated fluid flows related to diapirs of alkaline-ultrabasic or alkaline-basic composition. It is supposed that their formation was related to post-collisional extension during the early stages of the evolution of the Aptian–Late Cretaceous Indigirka belt of crust extension. All studied Li-F granites are enriched with rare metals and have associated Li deposits with accompanying Sn, W, Ta, and Nb mineralization. In the low-P Li-F Omchikandya massif, mineralization tends to occur within greisenized granites and greisens in their apical parts. In the high-P granite massifs, mineralization is found throughout their volume, and, therefore, the Verkhne–Burgali ethmolith and Kester harpolith can be considered as large ore bodies. There is a direct dependence of the content and reserves of Li
2 O on the content of P2 O5 . Minimum Li2 O reserves are established in low-P Li-F microcline–albite granites of the Polyarnoe deposit of the Omchikandya ore field, whereas in the high-P granites of the Verkhne–Burgali and Kester deposits, the Li2 O reserves are significantly higher. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
39. What is mineral informatics?
- Author
-
Prabhu, Anirudh, Morrison, Shaunna M., Fox, Peter, Ma, Xiaogang, Wong, Michael L., Williams, Jason R., McGuinness, Kenneth N., Krivovichev, Sergey V., Lehnert, Kerstin, Ralph, Jolyon, Lafuente, Barbara, Downs, Robert T., Walter, Michael J., and Hazen, Robert M.
- Subjects
MINERALS ,MEDICAL informatics ,NURSING informatics ,ORIGIN of life ,LITHOSPHERE ,DATA science ,MINERALOGY - Abstract
Minerals are information-rich materials that offer researchers a glimpse into the evolution of planetary bodies. Thus, it is important to extract, analyze, and interpret this abundance of information to improve our understanding of the planetary bodies in our solar system and the role our planet's geosphere played in the origin and evolution of life. Over the past several decades, data-driven efforts in mineralogy have seen a gradual increase. The development and application of data science and analytics methods to mineralogy, while extremely promising, has also been somewhat ad hoc in nature. To systematize and synthesize the direction of these efforts, we introduce the concept of "Mineral Informatics," which is the next frontier for researchers working with mineral data. In this paper, we present our vision for Mineral Informatics and the X-Informatics underpinnings that led to its conception, as well as the needs, challenges, opportunities, and future directions of the field. The intention of this paper is not to create a new specific field or a sub-field as a separate silo, but to document the needs of researchers studying minerals in various contexts and fields of study, to demonstrate how the systemization and enhanced access to mineralogical data will increase cross- and interdisciplinary studies, and how data science and informatics methods are a key next step in integrative mineralogical studies. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
40. 秦岭地区大桥金矿金的赋存状态及难选性因素探讨.
- Author
-
常静, 石磊, 李玺, 钟财丽, and 王艳
- Abstract
Copyright of Multipurpose Utilization of Mineral Resources / Kuangchan Zonghe Liyong is the property of Multipurpose Utilization of Mineral Resources Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2023
- Full Text
- View/download PDF
41. Industrial Heap Bioleaching of Copper Sulfide Ore Started with Only Water Irrigation
- Author
-
Xinliang Feng, Renman Ruan, Yan Jia, Qiaoyi Tan, Xu Jingyuan, and Heyun Sun
- Subjects
inorganic chemicals ,Sulfide ,copper sulfide ore ,heap bioleaching ,pyrite ,sulfuric acid ,water irrigation ,chemistry.chemical_element ,engineering.material ,chemistry.chemical_compound ,Bioleaching ,Heap (data structure) ,chemistry.chemical_classification ,Geology ,Sulfuric acid ,Mineralogy ,Geotechnical Engineering and Engineering Geology ,Pulp and paper industry ,Copper ,Copper sulfide ,chemistry ,Leaching (chemistry) ,engineering ,Pyrite ,QE351-399.2 - Abstract
Sulfuric acid solution containing ferric iron is the extractant for industrial heap bioleaching of copper sulfides. To start a heap bioleaching plant, sulfuric acid is usually added to the irrigation solution to maintain adequate acidity (pH 1.0–2.0) for copper dissolution. An industrial practice of heap bioleaching of secondary copper sulfide ore that began with only water irrigation without the addition of sulfuric acid was successfully implemented and introduced in this manuscript. The mineral composition and their behavior related to the production and consumption of sulfuric acid during the bioleaching in heaps was analyzed. This indicated the possibility of self-generating of sulfuric acid in heaps without exogenous addition. After proving by batches of laboratory tests, industrial measures were implemented to promote the sulfide mineral oxidation in heaps throughout the acidifying stages, from a pH of 7.0 to 1.0, thus sulfuric acid and iron was produced especially by pyrite oxidation. After acidifying of the heaps, adapted microbial consortium was inoculated and established in a leaching system. The launch of the bioleaching heap and finally the production expansion were realized without the addition of sulfuric acid, showing great efficiency under low operation costs.
- Published
- 2021
42. OpenMindat: Open and FAIR mineralogy data from the Mindat database.
- Author
-
Ma, Xiaogang, Ralph, Jolyon, Zhang, Jiyin, Que, Xiang, Prabhu, Anirudh, Morrison, Shaunna M., Hazen, Robert M., Wyborn, Lesley, and Lehnert, Kerstin
- Subjects
DATABASES ,MINERALOGY ,OPEN data movement ,DATA scrubbing ,SCIENTIFIC discoveries - Abstract
The open data movement has brought revolutionary changes to the field of mineralogy. With a growing number of datasets made available through community efforts, researchers are now able to explore new scientific topics such as mineral ecology, mineral evolution and new classification systems. The recent results have shown that the necessary open data coupled with data science skills and expertise in mineralogy will lead to impressive new scientific discoveries. Yet, feedback from researchers also reflects the needs for better FAIRness of open data, that is, findable, accessible, interoperable and reusable for both humans and machines. In this paper, we present our recent work on building the open data service of Mindat, one of the largest mineral databases in the world. In the past years, Mindat has supported numerous scientific studies but a machine interface for data access has never been established. Through the OpenMindat project we have achieved solid progress on two activities: (1) cleanse data and improve data quality, and (2) build a data sharing platform and establish a machine interface for data query and access. We hope OpenMindat will help address the increasing data needs from researchers in mineralogy for an internationally recognized authoritative database that is fully compliant with the FAIR guiding principles and helps accelerate scientific discoveries. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
43. Chronological and Mineralogical Records of the Langqi Pluton, Fuzhou: Constraints on the Magma Mixing Process.
- Author
-
Chen, Zhouxin, Wang, Liyuan, and Yan, Xue
- Subjects
MAGMAS ,IGNEOUS intrusions ,PLAGIOCLASE ,PHENOCRYSTS ,MINERAL analysis ,ISOTOPIC analysis ,BIOTITE - Abstract
The mafic microgranular enclaves (MMEs) from Mesozoic intermediate-acid magmatic rocks, widely developed along the Fujian coast, are considered to be the results of large-scale crust–mantle interaction by magma mixing. This paper is based on zircon U-Pb chronology, along with zircon Hf isotope and mineral analyses for the host granite and MMEs from Langqi Island, in order to investigate the magma mixing mechanism of the Langqi pluton in Fuzhou, Southeast China. The results indicate that the MMEs were emplaced during the late Early Cretaceous (98.9 ± 2.2 Ma), identical to the age of the granite (100.1 ± 1.1 Ma) within the error range. The zircon εHf(t) values for the granite and MMEs are in the ranges of −2.1~0.0 and −1.7~+1.1. The zircon Hf isotope data indicate that both the granite and MMEs were predominantly derived from the ancient crustal basement of Cathaysia, with a partial mantle-derived contribution. The An values of plagioclase phenocrysts with oscillatory zoning patterns in the MMEs show oscillatory changes from the core to the rim, indicating multiple mixing events between the two magmas with different compositions. Amphiboles in the MMEs show characteristics of crust–mantle contamination, and the Ti migrated from the mafic magma with high concentration to the felsic magma with low concentration during the magma mixing process. Biotites in the host rock and MMEs belong to primary biotite, and they have relatively high MgO contents (ave. 12.78 wt.%) and relatively low FeO
T /(MgO + FeOT ) ratios (ave. 0.56), showing characteristics of crust–mantle contamination. The crust–mantle magma interaction in a crystal, mushy state played a significant role in controlling the formation and evolution of the Langqi pluton. The magmatism was predominantly sourced from mixing between the mantle-derived mafic magma and the crust-derived felsic magma during the subduction of the Paleo-Pacific Plate, resulting in the formation of the Langqi doleritic veins, granites, and MMEs. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
44. Mineralogy and trace element geochemistry of hydrothermal sulfides from the Ari vent field, Central Indian Ridge.
- Author
-
Choi, Sun Ki, Pak, Sang Joon, Kim, Jonguk, Shin, Ji Young, Yang, Seungjin, Jang, Hwimin, and Son, Seung-Kyu
- Subjects
SULFIDE minerals ,PYRITES ,MAGNETITE ,LASER ablation inductively coupled plasma mass spectrometry ,MINERALOGY ,GEOCHEMISTRY ,TRACE elements ,SULFIDES - Abstract
The Ari vent field (AVF) is an ultramafic-hosted seafloor massive sulfide (SMS) deposit in the middle part of the Central Indian Ridge. In this paper, we describe the detailed mineralogy and geochemistry of hydrothermal sulfide samples from the AVF, which can be classified into Fe–Cu- and Cu-rich types based on the major sulfide minerals. Sulfide mineralisation of the former type comprises: (1) stage I, early deposition of magnetite, pyrrhotite, isocubanite, chalcopyrite, and subhedral–euhedral pyrite under high-temperature fluid conditions (> 335 °C); (2) stage II, deposition of colloform pyrite, sphalerite, galena, and electrum from low-temperature fluids (< 200 °C) during the later mineralisation stage; and (3) stage III, seawater alteration that caused the precipitation of uraninite and chalcocite. This indicates that the fluids in the AVF had decreasing temperature and ƒS
2 and increasing ƒO2 as mineralisation proceeded. The Cu-rich sulfide samples have mineral assemblages and a paragenesis similar to those of the Fe–Cu-rich sulfide samples, but the higher proportion of isocubanite is indicative of relatively high-temperatures and reducing conditions during mineralisation. Bulk chemical compositions of the AVF sulfides are characterised by high U contents (up to 51.9 ppm) and a distinct Sn distribution (2.1–86.4 ppm) between the two different types of hydrothermal samples, which differ from those of other ultramafic-hosted sulfide deposits. The U content is controlled mainly by the precipitation of discrete uraninite grains (< 1 μm in size) on altered surfaces of pyrite and hematite. The oxidative alteration of Fe-bearing minerals caused the fixation of seawater-derived U. Laser ablation–inductively coupled plasma–mass spectrometry analysis showed that most trace elements occur in solid solution in the sulfide minerals, mainly controlled by the physicochemical conditions of the hydrothermal fluids (e.g. temperature, ƒS2 , and ƒO2 ). In particular, a comparative analysis of other mid-ocean ridge systems shows that the ultramafic-hosted sphalerite and pyrite are more enriched in Sn as compared with those hosted by basaltic rocks. However, the Fe–Cu-rich sulfide samples of the AVF are Sn-poor (< 10.2 ppm), because pyrite is substantially depleted in Sn (mostly < 1 ppm) as compared with sphalerite, regardless of the effect of the ultramafic-hosted mineralisation. This indicates that in situ trace element analysis of sphalerite and pyrite, especially for Sn, can provide insights into the different hydrothermal mineralisation in basaltic- and ultramafic-hosted systems, which cannot necessarily be inferred from bulk analysis. Our comparison also suggests that the Sn contents of ultramafic-hosted SMS deposits would be a possible source of Sn for the ultramafic-hosted volcanogenic massive sulfide (UM-VMS) deposit. The δ34 S values (+ 6.2 to + 8.5‰) of the pyrite record thermochemical sulfate reduction of seawater, which suggests that sulfur and most metals were predominantly leached from the associated host rocks with a contribution (29–40%) from reduced seawater sulfur. In conclusion, the AVF is a rock-dominated system that contains ultramafic-hosted mineralisation in the Central Indian Ridge. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
45. Photochromism, UV-Vis, Vibrational and Fluorescence Spectroscopy of Differently Colored Hackmanite.
- Author
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Song, Chuchu, Guo, Qingfeng, Liu, Yang, Rao, Yinghua, and Liao, Libing
- Subjects
FLUORESCENCE spectroscopy ,PHOTOCHROMIC materials ,PHOTOCHROMISM ,COLORS ,COLOR ,FLUORESCENCE - Abstract
Because of the rich fluorescent color and unique photochromic properties, hackmanite has attracted many mineralogists. In this paper, the basic gemmological characteristics and photochromic and fluorescence mechanisms of four different colors of hackmanite are further investigated through the study of their structural, compositional, and spectroscopic features. The results show the change in the color of hackmanite in photochromism is caused by the joint action of the F-center and the oxygen hole centers. The change in the UV-Vis spectra may be caused by the superposition of two peaks. Under 365 nm UV excitation, the peak of fluorescence spectra of 662 nm is related to the
2 ∏g →2 ∏u transition of S2 − , the blue emission at 441 nm is caused by the3 P0.1 →1 S0 transition of s2 ions (Pb2+ , Tl+ , Sn2+ Sb2+ ), and at 541 nm is caused by the Mn2+ center. The results are helpful in deepening the understanding of photochromism, fluorescence mechanism, and its structure, expanding the application of hackmanite. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
46. Study on precipitation and plugging mechanism in CO2 + O2 in-situ leaching of uranium in Nalinggou uranium deposit
- Author
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Chen, Ting, Liu, Jinhui, Yang, Yihan, Zhang, Jianjun, Xu, Qi, and Zhu, Liping
- Published
- 2024
- Full Text
- View/download PDF
47. Phreatic overgrowths on speleothems (POS) from the Mallorca caves: Morphology, mineralogy, and crystal fabric classification.
- Author
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Entrena, Ana, Auqué, Luis F., Gimeno, María J., and Fornós, Joan J.
- Subjects
CALCITE crystals ,CRYSTAL morphology ,GLOBAL warming ,MINERALOGY ,STALACTITES & stalagmites ,SPELEOTHEMS - Abstract
Phreatic overgrowths on speleothems (POS) are unique precipitates that are found in a small number of coastal caves around the world, like those in the Mallorca Island. Their growth is directly related to the water level of the brackish lakes connected to the sea characteristic of these caves and, therefore, they can be very reliable indicators of past sea levels. The study presented here characterizes and classifies an important number of POS samples collected in the coastal caves of Mallorca. The characterization includes not only the observations made on 117 handheld samples and on 102 thin sections from POS, but also the study of their mineralogy and their location in the caves. This study has provided the basis for a systematization of all these characteristics, some of which are reported here for the first time in POS samples. The results indicate that (1) most of the POS precipitate on stalactites, (2) calcite POS show branched internal and external texture and their most common crystal fabric is mosaic calcite and (3) aragonite POS show globular external texture and fan‐shaped internal texture, and their principal crystal fabric is needle‐like. All the aragonitic samples have been found above or at the same heights as the current sea level, which indicates that they have probably formed during warmer climates. The calcite POS have been found at heights above and below the present sea level and are interpreted as to have formed during cold and rainy periods. The systematization proposed in this paper could be applied and checked in other POS worldwide. Additionally, the combination of these results with the information obtained from studies on the present precipitation of these phreatic speleothems in some Mallorca caves has provided an insight on their formation conditions which will enlarge the utility of these speleothems as palaeoenvironmental indicators. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
48. Certification of Meissen Granite IAG GMN‐1 Using the GeoPT Proficiency Testing Certification Protocol.
- Author
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Potts, Philip J., Webb, Peter C., Gowing, Charles J.B., and Renno, Axel D.
- Subjects
- *
REFERENCE sources , *GRANITE , *MATERIALS testing , *MINERALOGY , *HOMOGENEITY - Abstract
Following a full assessment of the GeoPT proficiency testing scheme against the recommendations in ISO Guide 35:2017 for the use of proficiency testing in the certification of reference materials, this paper presents the first application of the GeoPT certification protocol in the characterisation of a new geochemical CRM, IAG GMN‐1, Meissen Granite. This protocol is applied to the measurement results reported in Round 51 of the GeoPT programme in which the candidate CRM was used as the test material, together with an established CRM (CGL 008 MGT‐1 Granite) to provide validation of the results. Following the presentation of mineralogy, grain‐size analysis and homogeneity testing data for IAG GMN‐1, certified values for nine major elements and thirty‐nine trace elements are reported. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
49. Thermal Activation of Kaolin: Effect of Kaolin Mineralogy on the Activation Process †.
- Author
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Kosmidi, Dimitra, Panagiotopoulou, Chrysa, Angelopoulos, Panagiotis, and Taxiarchou, Maria
- Subjects
HEAT ,KAOLIN ,MINERALOGY ,X-ray diffraction ,FOURIER transform infrared spectroscopy - Abstract
Kaolin is an industrial mineral used in a wide variety of applications due to its crystalline structure, mineral and elemental composition. After kaolin undergoes heat treatment in a specific temperature range, metakaolin, which exhibits a strong pozzolanic reaction, is formed. This paper examines the effects of different kaolin qualities on the thermal activation process of metakaolin production. The qualities of kaolin depend on the impurities they contain, such as mica, feldspar and quartz. In this study, four different samples of kaolin are investigated. Each sample was heat treated in a lab-scale rotary kiln in order to study the chemical, structural and morphological changes that occurred and their influence on pozzolanic activity. The parameters being considered in the experimental process were the temperature and the duration of the treatment. Thus, the calcination process for each of the four kaolin types was carried out at 600, 650 and 700 °C for 3 h. The occurred changes were monitored using XRD, FTIR and DTA analysis. Additionally, the reactivity of all thermally treated samples was evaluated based on the Chapelle test. The results showed that the fewer the impurities, the easier the transformation of the material to metakaolin. The optimum result was the metakaolin, which originated from the purest quality of kaolin and was comparable to the commercial product. Finally, the pozzolanic activity of the thermally activated samples also depended on the purity of the kaolin. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
50. Physicochemical Properties of Combustion Ashes of Some Trees (Urban Pruning) Present in the Neotropical Region.
- Author
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Gelves-Díaz, John Freddy, Dorkis, Ludovic, Monroy-Sepúlveda, Richard, Rozo-Rincón, Sandra, and Romero-Arcos, Yebrail Alexis
- Subjects
COMBUSTION ,PRUNING ,LIGNOCELLULOSE ,OXIDATION ,SCANNING electron microscopes - Abstract
Secondary lignocellulosic biomass has proved to be useful as an energy source through its oxidation by means of combustion processes. In accordance with the above, in this paper, we wanted to study the ash from urban pruning residues that are generated in cities in the Neotropics. Species such as Licania tomentosa, Azadirachta indica, Ficus benjamina, Terminalia catappa, Leucaena leucocephala, Prosopis juliflora and Pithecellobium dulce were selected because they have been previously studied and showed potential for thermal energy generation. These materials were calcined in an oxidizing atmosphere and characterized by X-ray diffraction and fluorescence, scanning electron microscopy with microchemistry, BET surface area, thermal gravimetric analysis, and differential scanning calorimetry. The pH and apparent density were also established. The results show high basicity materials (average pH 10), a behavior associated with the presence of chemical elements such as calcium, potassium, magnesium, chlorine, phosphorus, and sulfur. Structurally, these materials have a very significant amorphous fraction (between 49% and 74.5%), the dominant crystalline phases are calcite, arcanite, sylvite, and hydroxyapatite. These ashes have low surface area and do not exceed 13 m2/g. Two characteristic morphological aspects were observed in these ashes: a morphology of rounded grains where silicon content is highlighted, and lamellar morphologies where the presence of chlorine is highlighted. Thermally, these ashes show four significant mass loss events (400°C, 430°C, 680°C, and 920°C), causing mass losses that vary between 25% and 40%. Through this study, it was possible to establish that, from a chemical point of view, these ashes are less dangerous in comparison with those of a mineral coal that was used as a reference. However, they require additional treatments for their disposal due to their high basicity. Because of their composition, these ashes have the potential to be used in the ceramic and cement industries, and in the manufacture of fertilizers. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
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