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Ultra-High Molecular Weight Polyethylene (UHMWPE) polymers have been used in biomedical applications due to its biocompatibility, durability, toughness and high wear resistance. To enhance the mechanical properties, various types of minerals are commonly utilized as fillers in UHMWPE. One of the minerals is dolomite, which has been recognized as a valuable mineral with versatile applications, particularly in the field of biomedical applications. This paper presents the tensile properties of UHMWPE composites that filled with dolomite and treated-dolomite at various filler loading (i.e., 1-5 wt.%). Nitric acid and diammonium phosphate were used to treat the dolomite. From the results, the peaks of the FTIR spectrum displays carbonate (CO3–2), phosphate (PO4–3) and hydroxyl (OH–) groups in the ct-dolomite powder sample while the XRD pattern reveals that using dolomite treated with 1M nitric acid resulted in the presence of calcium hydroxide phosphate (Ca10(PO4)5(OH)) and MgO. For tensile strength, UHMWPE/ct-dolomite composites show better tensile strength than the pure UHMWPE composites. Treated improve the dolomite filler and resulted in significantly better matrix-filler interfacial interactions and improve the properties.

In the paper, changes of pH value during 20 days of soil interaction with the solution have been traced. Differences in the reaction rate using ameliorants of different chemical nature for liming have been established. It was revealed that the ameliorative effect of using materials of silicate nature in the experiment was lower than that of carbonate nature. According to the effect all ameliorants used in the experiment can be arranged in the following descending order: dolomite flour (DF), crushed stone sieve (CSS) > conversion chalk (CC), dolomitized limestone flour (DLF) > blast furnace slag (BFS) > oil shale ash (OSA). For all lime fertilizers empirical models of pHKCL value change over the whole experimental interval were developed. Clustering of separate variants of the experiment, produced by different ameliorants on their influence on the index rNKCL on the whole interval of study was carried out.

In the first part of this paper the occurrence of dolomite in B&H karst, as well as active and potential dolomite deposits for dimension stone with different trade names ("Rujan" , "San", "Gradac") are presented, with the available results of their testing. The final section of the paper gives a brief historical overview of the applications of dolomite as dimension stone in Herzegovina, which is attested by many tombstones, but also some religious and residential buildings. However, with its beauty of textures and colors and quality in workmanship, in the last several decades it has been widely used in the interior and exterior cladding of numerous buildings in Herzegovina, as well as in several regional architectural projects along the Adriatic coast, in the Republic of Croatia and Republic of Montenegro. The final section of the paper provides relevant conclusions related to the application of dolomite as dimension stone.

Although archaeological excavations have recovered a large number of vessels used to hold perfumes or ointments in ancient Rome, little is known about the chemical composition or origin of the substances they contained. Most available information pertains to ointment and/or cosmetic bases rather than to essences. The discovery in 2019 of an ointment jar (unguentarium) made of rock crystal (quartz) that was sealed with a stopper and contained a solid mass in a Roman tomb in Carmona (Seville, Spain) was a rather unusual finding. This paper reports the results of an archaeometric study of the unguentarium stopper and its contents. Based on them, and on comparisons with commercially available patchouli and nard oil standards, the perfume held in the unguentarium was probably patchouli. To our knowledge, this may be the first time a perfume from Roman times has been identified, which is a major advance in this field. The unguentarium stopper consisted of dolomite, a material also unknown in this type of use, and bitumen was used to seal the unguentarium with the stopper.

Flotation is the main method to improve the quality and reduce the impurity of calcium magnesium phosphate ore. However, the similar surface physical and chemical properties of dolomite and fluorapatite make it difficult to separate efficiently. With the development of quantum mechanics and computational chemistry, molecular simulation has gradually become an effective tool for studying the flotation of calcium magnesium phosphate ore. It provides a new method for studying the crystal chemical properties of the main minerals in calcium-magnesium phosphate ore and the interaction between mineral interfaces. On the basis of reviewing the research, especially the wettability, surface electricity and surface adsorption characteristics, this paper summarizes the methods of molecular simulation, and the application of density functional theory(DFT)and molecular dynamics simulation(MDS)in the flotation separation of fluorapatite and dolomite, including the chemical properties of crystals, the interaction of water molecules and reagents with mineral surfaces. In addition, the application prospects of molecular simulation in phosphate ore flotation research are also discussed.

Acid treatment is one of the main methods of stimulating the near wellbore area of the wells opening the carbonate reservoirs. Despite the extensive experience of using this technology both in Russia and abroad, as well as a significant number of studies, the success rate is hardly ever estimated at over 30%. One of the reasons for the low success rate is neglect to the changes in the physical properties of fluids during injection, interaction with the rock and the properties of the reaction products in the wellbore and the near wellbore area during the acid treatment planning. This paper discusses the main chemical reactions occurring during the interaction of hydrochloric acid with limestones and dolomites. The quantities of the substances resulting from a chemical reaction between 15% aqueous solution of acid and the carbonates have been determined. The properties (phase state, solubility, dependences of viscosity and density on pressure and temperature) of water, carbon dioxide, nitrogen, 15% aqueous solution of acid, solutions of calcium and magnesium chloride salts in the range of possible pressures and temperatures during the acid treatment were evaluated. Due to the diversity of additives used in acid solutions, the paper proves the necessity of conducting laboratory experiments to evaluate their properties under the conditions expected during the acid stimulation. Based on laboratory studies, the reaction time of 15% solution of hydrochloric acid with calcium carbonate was estimated. The impact of the chemical diverter used for primary treatments at the Badra oilfield (Iraq) on the properties of the acid solution and the reaction time was determined. The changes in the solution viscosity depending on the acid temperature and concentration were determined. The results provided in the work were used for the purposes of forecasting and evaluating the efficiency of acid treatment performed on the wells of the Badra oilfield.

Smithsonite, dolomite, and calcite are carbonate minerals. The crystal structures and spatial distribution characteristics of their common surface metal sites are similar, leading to difficulty in the flotation separation of smithsonite from these carbonate gangues. In this paper, the floatability of smithsonite, dolomite, and calcite in sodium oleate, salicylhydroxamic acid, and their combined-collector system were systematically studied through single-mineral flotation tests, respectively. The results showed that it was difficult to obtain a noticeable recovery difference between smithsonite–calcite and smithsonite–dolomite in a single-collector system of sodium oleate and salicylhydroxamic acid, both at the same time. In the combined-collector system of salicylhydroxamic acid and sodium oleate with total dosage of 6 × 10−4 mol/L, molar ratio of 3:1, and pH of 8.0, the recovery difference of smithsonite–calcite and smithsonite–dolomite could reach the highest values of 38.46% and 37.98%, respectively, while obtaining the highest smithsonite recovery of 88.19%. The adsorption mechanism of the combined collectors was investigated via Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, a collector adsorption test, and zeta potential measurements, respectively.

In the field of mineral processing, the successful flotation of target minerals requires sufficient liberation through grinding. The aim of this paper is to compare and evaluate the performance of ball versus short cylindrical media for comminution of dolomite by point and line contact, respectively. The results of the grinding experiments indicate that short cylinders generate more angular particles with intermediate sizes and exhibit a higher grinding efficiency compared to balls. The Population Balance Model demonstrates the distribution of broken fragment sizes during the breaking stage for each size range. The results of the DEM (discrete element method) grinding simulation are consistent with the experimental findings in terms of the distribution of particle sizes, the shape of the particles, and the distribution of broken fragment sizes. Furthermore, short cylinders selectively produce more active {104} crystal surface of dolomite, which possess a higher adsorption capacity with collectors and are preferentially floated as the concentrate. In reverse flotation for removal of dolomite, tests confirm that the products obtained from grinding with short cylinders exhibit a higher flotation recovery of dolomite compared to those obtained from ball grinding. This study provides a reference scheme for optimizing the grinding and flotation processes of valuable minerals.

Geopolymer is widely studied nowadays in various scope of studies. Some of the ongoing studies are the study of the various materials towards the geopolymer strength produced. Meanwhile, some of the studies focus on the mixing of the geopolymer itself. This paper discussed the phase analysis of metakaolin/dolomite geopolymer for different solid to the liquid ratio which was, 0.4, 0.6, 0.8, and 1.0, and the properties that affected the geopolymer based on the phases. The constant parameters in this study were the percentage of metakaolin and dolomite used. The metakaolin used was 80% meanwhile dolomite usage was 20%. Besides that, the molarity of NaOH used is 10M and the alkaline activator ratio used is 2.0. All the samples were tested at 28 days of curing. The results show that the 0.8 solid to the liquid ratio used gave better properties compare to other solid to liquid ratio. The phases analyzed were quartz, sillimanite, mullite, and faujasite. The 0.8 S/L ratio shows the better properties compared to others by the test of phase analysis, compressive strength morphology analysis, and functional group analysis.

The depletion of ore deposits, the increasing demand for raw materials, the need to process low-grade, complex and finely disseminated ores, and the reprocessing of tailings are challenges especially for froth flotation separation technologies. Even though they are capable of handling relatively fine grain sizes, the flotation separation of very fine and ultrafine particles faces many problems still. Further, the flotation of low-contrast semi-soluble salt-type minerals with very similar surface properties, many complex interactions between minerals, reagents and dissolved species often result in poor selectivity. This study investigates the flotation beneficiation of ultrafine magnesite rich in dolomite from desliming, currently reported to the tailings. The paper especially focuses on the impact of the depressant sodium hexametaphosphate (SHMP) on the following: (i) the froth properties using dynamic froth analysis (DFA), (ii) the separation between magnesite and dolomite/calcite, and (iii) its effect on the entrainment. As a depressant/dispersant, SHMP has a beneficial impact on the flotation separation between magnesite and dolomite. However, there is a trade-off between grade and recovery, and as well as the dewatering process which needs to be considered. When the SHMP increases from 200 g/t to 700 g/t, the magnesite grade increases from 67% to 77%, while recovery decreases massively, from 80% to 40%. The open circuit with four cleaning stages obtained a concentrate assaying 77.5% magnesite at a recovery of 45.5%. The dolomite content in the concentrate is about 20%, where 80% of dolomite was removed and importantly 98% of the quartz was removed, with only 0.3% of the quartz in the final concentrate. Furthermore, the application of 1-hydroxyethylene-1,1-diphosphonic acid (HEDP) as a more environmentally friendly and low-cost alternative to SHMP is presented and discussed. Using only 350 g/t of HEDP can achieve a similar grade (76.3%), like 700 g/t of SHMP (76.9%), while obtaining a 17% higher magnesite recovery as compared to 700 g/t of SHMP. Interestingly, the proportion of hydrophilic quartz minerals ending up in the concentrate is lower for HEDP, with only 1.9% quartz at a recovery of 21.5% compared to the 2.7% of quartz at a recovery of 24.9% when using SHMP. The paper contributes in general to understanding the complexity of the depressant responses in froth flotation.

Heavy metal pollution derived from the oxidation of sulfides in Pb-Zn mine tailings has been a common public concern. Although the oxidative dissolution of sphalerite will release cadmium into the soil environment, it is still unclear whether other minerals contain a large amount of cadmium and how much these minerals contribute to the surrounding environmental media. In this paper, XRD, particle size analyzer, SEM-EDS and improved BCR sequential extraction method were used to analyze cadmium rich zinc mine tailing and adjacent farmland soil in Duyun, Guizhou Province. The results show that the average contents of Pb, Zn, and Cd in tailing are 214 ± 71 mg/kg, 2668 ± 773 mg/kg, and 37.5 ± 9.97 mg/kg respectively. While in the surrounding soil, they were 519 ± 280 mg/kg, 3,779 ± 2614 mg/kg, and 30.8 ± 14.4 mg/kg respectively. The mineralogical composition of tailing is mainly dolomite and less pyrite. Cadmium in tailing is mainly in weak acid extractable state, indicating that cadmium mainly exists in dolomite of tailing. Pyrite in tailing generates acid through oxidation, which accelerates the dissolution of dolomite, thus releasing Cd from minerals and migrating to surrounding farmland, resulting in soil cadmium pollution. This study reveals an important process that has been neglected. Carbonate minerals play an important role in the migration of cadmium in the tailing of the Mississippi Valley-type (MVT) lead-zinc mine and the soils affected by the tailing.

The removal of hazardous heavy metals that have been released into the environment due to industrial activities has become an important issue in recent years. The presented study concerned the removal of copper(II) ions from aqueous solutions using dolomites. Dolomite is a very attractive adsorbent due to its wide availability, low cost, good adsorption, and environmental compatibility. The paper describes the properties of D-I and D-II dolomites from two different open-cast mines in Poland. The properties of natural adsorbents were determined based on point of zero charges (PZC), elemental analysis of the adsorbent composition, FT-IR, XRD, and SEM spectra analysis. Depending on the initial concentration of the solution used, the adsorption efficiency of copper(II) ions was 58–80% for D-I and 80–97% for D-II. The adsorption mechanism in the case of D-II dolomite was mainly based on ion exchange, while chemisorption dominated the D-I dolomite surface. Considering the possibility of the regeneration and reuse of the adsorbent, dolomite D-II is a better material (the desorption efficiency of copper(II) ions was 58–80%). The adsorption behavior of dolomites has been described using six adsorption isotherms. The best fit was obtained for the Redlich–Peterson, Jovanović, and Langmuir isotherms, indicating that monolayer adsorption occurred. The maximum adsorption capacity for copper(II) was 378 mg/g of D-I and 308 mg/g of D-II.

Reasonable matching structure of sintering flux has great effect on improving the sinter quality and reducing energy consumption. In this paper, the feasibility of replacing part or all of quick lime in sintering production with limestone, dolomite, light burnt magnesium powder and light burnt dolomite is studied by sinter pot test in the lab. The result shows that when with 5,47 % of light burnt dolomite replacing part of the quick lime, the results such as the weighted average of sinter granularity, the production yield, the utilization coefficient, the tumbler index and the reduction degree meet the actual production requirements.

The paper presents research results of heavy metal ions sorption from a model solution and wastewater of an electroplating enterprise under static conditions. The purpose of this work is to develop a technology of tertiary treatment of electroplating production wastewater from heavy metals to achieve MPC levels for fresh fishery water bodies using local powder sorption materials. The authors examined such sorbents as modified clay (MC) obtained by thermal modification of its natural components (montmorillonite, kaolinite, peat, dolomite), as well as certain primary components and their mixtures without thermal modification. The studies were conducted at low initial concentrations of heavy metals (from 0.002 to 2.8 mg/l) characteristic of wastewater subjected to tertiary treatment. The concentration of heavy metals in wastewater was determined by inductively coupled plasma optical emission spectrometry on Avio™ 200. The research demonstrated that the contact time required to achieve the equilibrium of the treated wastewater and the modified clay sorbent varied from 60 to 120 minutes for the investigated heavy metals. Taking into account the time required to reach the MPCs of heavy metals for fresh fishery water bodies, the estimated contact duration of 90 minutes was recommended. The calculated dose of the modified clay sorbent, sufficient for tertiary treatment of acid-base wastewater of electroplating production to the MPC, was 1 g/l. Experiments with unmodified materials conducted on a multicomponent model solution showed that montmorillonite had the best sorption properties, ensuring the achievement of MPC for all metals, except aluminum, at doses from 0.1 to 0.9 g/l. Peat was the most effective in extracting nickel to MPC with its estimated dose being 0.1 g/l. Dolomite turned out to be the only material that provided the removal of aluminum to MPC at a dose of 1 g/l. The obtained results suggest that it is possible to increase the efficiency of heavy metals removal by selecting sorbent mixture without thermal modification and with mixed sorbent dose of 1–1.6 g/l. The authors recommend a technology of tertiary treatment of acid-base wastewater of electroplating production. This technology is to carry out the sorption process under static conditions using powder sorbents based on local natural materials, followed by separation of the spent sorbent with a precoat cartridge filter.

In this paper, the Johnson-Holmquist concrete (JHC) constitutive model is adopted for modeling and simulating the fracture of dolomite. A detailed step-by-step procedure for determining all required parameters, based on a series of experiments under quasi-static and dynamic regimes, is proposed. Strain rate coefficients, failure surfaces, equations of state and damage/failure constants are acquired based on the experimental data and finite element analyses. The JHC model with the obtained parameters for dolomite is subsequently validated using quasi-static uniaxial and triaxial compression tests as well as dynamic split Hopkinson pressure bar (SHPB) tests. The influence of mesh size is also analyzed. It shows that the simulated fracture behavior and waveform data are in good agreement with the experimental data for all tests under both quasi-static and dynamic loading conditions. Future studies will implement the validated JHC model in small- and large-scale blasting simulations.

Worldwide, the known recoverable heavy oil and bitumen reserves make up more than 64% of the total reserves, of which more than 60% are trapped in carbonates. Air injection has immense potential for hydrocarbon recovery from various reservoirs. While most of the successful air-based techniques are performed within carbonate reservoirs containing light oil, theoretically, in situ combustion (ISC) has also shown great potential for recovering heavy oil and bitumen. Carbonates are complex in terms of geology and are often associated with fractures and vugs that affect the fluid flow, pressure propagation and progression of the ISC reactions. This paper describes the first experiment in which the triple-porosity concept was applied to simulate heterogeneity through artificially induced vugs, core matrix and fractures. This approach was used to study the feasibility of the ISC recovery technique for heavy oil (14° API) within a dolomite reservoir using a combustion tube (CT) in an experiment performed at 1740 psig. The combustion front advanced through 78% of the core length prior to the termination of air injection, producing 80% of the initial oil. To differentiate between the various sources of the CO2 gas (a product of carbonate decomposition vs. the combustion reaction) the atomic ratios of (CO2 + CO)/CO = 6 and (CO2 + CO)/N2 = 0.21 were applied. Additionally, partial upgrading of the produced heavy oil was observed.

The paper focuses on the theoretical description of the cleaning of syngas from biomass and waste gasification using catalytic methods, and on the verification of the theory through experiments. The main obstruction to using syngas from fluid gasification of organic matter is the presence of various high-boiling point hydrocarbons (i.e., tar) in the gas. The elimination of tar from the gas is a key factor in subsequent use of the gas in other technologies for cogeneration of electrical energy and heat. The application of a natural or artificial catalyst for catalytic destruction of tar is one of the methods of secondary elimination of tar from syngas. In our experiments, we used a natural catalyst (dolomite or calcium magnesium carbonate) from Horní Lánov with great mechanical and catalytic properties, suitable for our purposes. The advantages of natural catalysts in contrast to artificial catalysts include their availability, low purchase prices and higher resilience to the so-called catalyst poison. Natural calcium catalysts may also capture undesired compounds of sulphure and chlorine. Our paper presents a theoretical description and analysis of catalytic destruction of tar into combustible gas components, and of the impact of dolomite calcination on its efficiency. The efficiency of the technology is verified in laboratories. The facility used for verification was a 150 kW pilot gasification unit with a laboratory catalytic filter. The efficiency of tar elimination reached 99.5%, the tar concentration complied with limits for use of the gas in combustion engines, and the tar content reached approximately 35 mg/mn3. The results of the measurements conducted in laboratories helped us design a pilot technology for catalytic gas cleaning.

Employing dolomite in the capacity of a sorbent for generator gas purification is of considerable interest nowadays, as it is the impurity of generator gas that causes the major problem for creating cheep and effective co-generator plants. Designing gas purification systems employs simple but physically adequate macrokinetic models of dolomite thermal decomposition. The paper analyzes peculiarities of several contemporaneous models of dolomite and calcite thermal decomposition and infers on reasonable practicality for creating compact engineering dolomite-decomposition macrokinetic models and universal techniques of these models parameter reconstruction for specific dolomite samples. Such technics can be founded on thermogravimetric data and standard approximation error minimizing algorithms.The author assumes that CO2 evacuation from the reaction zone within the particle may proceed by diffusion mechanism and/or by the Darcy filtration and indicates that functional dependence of the thermal-decomposition rate from the particle sizes and the temperature differs for the specified mechanisms. The paper formulates four macrokinetic models whose correspondence verification is grounded on the experimental data. The author concludes that further work in this direction should proceed with the dolomite samples investigation and selecting the best approximation model describing experimental data in wide range of temperatures, warming up rates and the particle sizes.

In heat transfer applications, heat pipes are widely- preferred because of some characteristics such as low cost, being able to be produced in any size and low maintenance cost make them superior. Moreover, the working fluid to be employed substantially affects the heat transfer characteristics of a heat pipe. In this paper, effects of nanoparticle addition into the ethylene glycol on heat pipe’s thermal performance were analysed experimentally. Every test was done using two variant working fluids, ethylene glycol and dolomite nanoparticles-doped ethylene glycol, respectively. Dolomite nanoparticles (2% by weight) and Sodium Dodecyl Benzene Sulfonate (0.5% by weight) were doped into the ethylene glycol while preparing the dolomite/ethylene glycol nanofluid. After filling in the heat pipe, experiments were realized under changing working conditions. Using experimental data, efficiency and thermal resistance of the heat pipe were examined. Viscosity of the each working fluid was determined. The contact angle –wettability measurements were also performed to specify the effects of surface active agent addition. The obtained findings revealed that nanoparticle inclusion inside the base fluid, i.e. ethylene glycol, improved the thermal performance (efficiency) and decreased the heat pipe’s thermal resistance substantially. ©2020. CBIORE-IJRED. All rights reserved

Carbonate rocks contain about 60 % of global oil and gas reserves. Stimulation of wells tapping into carbonate reservoirs is often performed using hydrochloric acid treatments based on the chemical reaction of hydrochloric acid with carbonate minerals. Carbonate reservoirs generally exhibit significant inhomogeneity, therefore the acid being injected into the formation causes uneven rock dissolution in the near-wellbore region, resulting in the emergence of highly conductive flow channels (wormholes) with complex geometry. They ensure a good hydrodynamic connection between the well and the formation. Each specific rock-acid compound system has an optimum injection rate which can help form long weakly ramified wormholes at minimum acid injection volume. The optimum injection rate value is influenced by many factors, such as pressure, temperature, acid concentration, solution composition, mineral composition of rock etc. As of today, laboratory research is the main method to determine the optimum parameters for treating the near-wellbore formation region with acid. The paper summarises the results of the analysis examining the influence of various factors on the optimum injection rate and the amount of injected pore volumes of an acid compound until a wormhole breakthrough. It is shown that the factors have a cumulative effect on the effectiveness of the acid treatment and have to be considered simultaneously in laboratory tests. The results of the performed analysis have been taken into account when planning further laboratory research. Within the design scope of hydrochloric acid treatments in wells of one of Iraq’s carbonate fields, laboratory tests have been conducted to assess the impact of acid concentration and injection rate on the effectiveness of acid stimulation in the conditions that were expected in case of the hydrochloric acid treatment. The determined injection parameters help obtain an optimum structure of wormholes at a minimum acid injection volume. The results of the performed research have been successfully used to design hydrochloric acid treatments in wells of the field under study.

Introduction Mississippi Valley-Type (MVT) deposits are epigenetic zinc and lead deposits with minor copper hosted by dolostone, limestone, and locally sandstone in platform carbonate sequences inboard of major orogenic belts (Leach and Sangster, 1993; Leach et al., 2010). The Irankuh-Ahangaran Belt, which is the most important Pb-Zn mineralized zone of Iran, is situated within the Sanandaj-Sirjan tectonic zone. This belt is 400 km in length and 100 km in width. Three deposits including Irankuh mininig district, Ahangaran and Hosseinabad deposits were studied in this article (Fig. 1). The aim of this research is study of thermal gradient of subducted slab and age of formation of Pb-Zn deposits at Irankuh-Ahangaran belt, which is contrary information has been published so far on the type and their formation. Also, chemistry of ore-fluid in MVT deposits and impact of dolomitic and shale host rock on paragenesis, alteration, style, reserves and grade of deposits were discussed.These parameters will certainly be useful for exploration of the hidden MVT type deposits in the Irankou-Ahangan belt. Result and Discussion The Irankuh mineralization is hosted by Cretaceous dolostone and minor Jurassic shale rocks as epigenetic. The constructive thrust fault, which has been cut the Jurassic and Cretaceous host rocks, has played a major role in the rising of fluid and formation of mineralization. Mineralization is occurred as replacement and open space filling (fault breccia, veinlets and cavity of rock) in dolostone and breccia, veinlet and open space filling in shale host rock. The mineral assembelages are Fe-rich sphalerite, Fe- and Mn-rich dolomite, ankrite, galena, minor pyrite, bituminous, calcite ± quartz ± barite within carbonate host rocks, whereas quartz, pyrite, Fe-rich sphalerite, galena, minor chalcopyrite, low Fe-dolomite, bituminous, ± barite ± calcite are important primary minerals at clastic hos rocks (Karimpour et al., 2018). The Ahangaran deposit is very similar to Irankuh in host rock, alteration, paragenesis, and form of mineralization. Thrust fault has a constructive role for occurrence of mineralization and later destructive strike slip and normal faults have caused the displacement and destruction of mineralization. The Hosseinabad deposit is hosted by Jurassic shale, siltstone, and sandstone rocks as vein-veinlets, breccia and open space filling with structural control. Alteratin consists of silicification, chlorite, bituminous, and minor siderite, dolomite and ankerite similar to mineralization hosted by shale in Irankuh district. The mineral assemblages are galena, Fe-rich sphalerite, pyrite, chalcopyrite and minor phyrotite. Due to the lack of a proper dolostone unit in the Husseinabad deposit, mineralization is concentrated in particular areas with low-grade and low-reserves. Based on lithology, alteration, mineralization style, structural control by thrust faults, mineral paragenesis, and comparison with differnet types of Pb-Zn deposits, all deposits of Irankuh-Ahangaran belt are MVT-type. Deep-seated thrust faults formed during the early stages of subduction (~ 70 to 75 Ma), and played an important role in the upward migration of hydrothermal fluids from the basement to shallow depths. The geochronology of pyrite in Irankuh district based on Re-Os method indicate age of Irankuh Pb-Zn mineralization is 66.5 ± 1.6 Ma (Liu et al., 2019). Since the thrust faults have been cut the Jurassic to Upper Cretaceous rocks, and according to the absoulte age determined in Irankuh, the mineralization of this belt have been formed in the age range of 66 to 56 million years ago, mainly in the Paleocene (Fig. 15). Karimpour and Sadeghi (2018) suggested the hydrothermal fluid originated from the dehydration of a hot and young oceanic subducted slab, which liberated Pb, Zn, and other metals, and may have removed metals from rocks and organic material of the continental crust. More than 90% of all the water within the oceanic slab was released in the depth zone of the forearc region (depth of 30 to 50 km) (Karimpour and Sadeghi, 2018). In the depth zone, Mg-rich silicate minerals (such as antigorite, hornblende, chlorite, talc) have broken and the produced fluid is rich in Mg and Fe (Fig. 17). The ore-fluid of MVT deposits is Si-poor and Fe- and Mg- rich. Such fluid is mineralized on the hosts of the dolstone (Irankuh and Ahangaran) or Shale-Siltstone (Hossein Abad, and part of Irankuh and Ahangaran). There are significant differences in the type of paragenesis, alteration, shape, dimensions, reserves and grade in the deposits of this belt, which is controlled by the host rock type. Based on all lithological evidence, alteration, shape of mineralization, existence of thrust faults, mineral paragenesis and specific geological and geographic location, it can be used to exploration of the hidden MVT deposits in this belt. References Karimpour, M.H., Malekzadeh Shafaroudi, A., Esmaeili Sevieri, A., Shabani, S., Allaz, J.M. and Stern, C.R., 2018b. Geology, mineralization, mineral chemistry, and ore-fluid conditions of Irankuh Pb-Zn mining district, south of Isfahan. Journal of Economic Geology, 9(2): 267–294. (in Persian with English abstract) Karimpour, M.H. and Sadeghi, M., 2018. Dehydration of hot oceanic slab at depth 30–50 km: KEY to formation of Irankuh-Emarat Pb-Zn MVT belt, Central Iran. Journal of Geochemical Exploration, 194: 88–103. Leach, D.L. and Sangster, D., 1993. Mississippi Valley-type lead-zinc deposits. Geological Association of Canadian. Specific Paper, 40: 289–314. Leach, D.L, Taylor, R.D., Fey, D.L., Diehl, S.F. and Saltus, R.W., 2010. A Deposit Model for Mississippi Valley-Type Lead-Zinc Ores, Chapter A of Mineral Deposit Models for Resource Assessment. U.S. Geological Survey, Reston, Virginia, Scientific Investigations Report 2010–5070–A., 64 pp. Liu, Y., Song, Y., Fard, M., Zhou, L., Hou, Z. and Kendricke, M.A., 2019. Pyrite Re-Os age constraints on the Irankuh Zn-Pb deposit, Iran, and regional implications. Ore Geology Reviews, 104: 148–159.

Lower Cambrian Xiaoerblak Formation is one of the major exploration targets in Cambrian pre-salt Tarim Basin; however, the exploration breakthrough is restricted by insufficient understanding of its sedimentary evolution and reservoir genesis. In this paper, based on a systematic description of the outcrop in the Xiaoerblak section, northwestern Tarim Basin, some samples were selected for tests of stable carbon and oxygen isotopic compositions, strontium isotopic composition, order degree, trace and rare earth elements, U-Pb isotopic age and clumped isotope. It is found that the Xiaoerblak Formation mainly develops nine types of dolomites, i.e., laminated microbial dolomite, thrombolite dolomite, stromatolite dolomite, foamy microbial dolomite, grain dolomite, etc. According to the lithofacies associations, it can be divided into three members: Xi 1, Xi 2, and Xi 3, of which member Xi 2 is subdivided into three submembers. The characteristics of lithofacies assemblage formed bottom to top indicate that it can be described as a third-order sequence. The Xiaoerblak Formation was deposited in a nearshore shallow seawater environment characterized by high water salinity and temperature under a warm and humid climate during the Early Cambrian, giving rise to the sedimentary sequence of inner ramp lagoon, subtidal microbial mound shoal and tidal flat in the carbonate ramp setting from bottom to top. Its dolomitization occurred in the penecontemporaneous–shallow burial period when the temperature was relatively low and high-salinity seawater acted as the main dolomitizaiton fluid. The reservoir space mainly comprises primary microbial framework pores and vugs formed by the atmospheric freshwater dissolution. Reservoirs were controlled by lithofacies, high-frequency sequence boundary and early dolomitization. The research results are of great significance for presalt Cambrian lithofacies paleogeographic mapping and reservoir prediction.

Inorganic ceramic membranes have attracted much attention due to their advantages of long life, acid and alkali corrosion resistance, and easy cleaning, but they have not been widely used due to the high cost. In order to obtain a ceramic membrane with low cost and good performance, in this paper, loess-based ceramic membrane support was prepared by using loess as raw material, bauxite as aluminum source, dolomite as pore-forming agent and talc as plasticizer. Response surface optimization was used to determine the optimal addition parameters of ingredients. In addition, the factors affecting the performance of the supports were analyzed in terms of material composition, microscopic morphology, and porosity. The results show that the addition of talc conduced to avoid the negative impact of the pore-forming effect of dolomite on the mechanical strength of the support, and the optimum proportioning parameters are 48.85 wt% of bauxite, 9.93 wt% of dolomite and 8 wt% of talc. Under this condition, the bending strength was 42.24 MPa, the pure water flux was 8323.73 l·m ^−2 ·h ^−1 ·MPa ^−1 , and the average pore throat radius was 5.15 μ m. The performance of the best sample reaches the application performance of porous ceramic supports, which provides a theoretical basis for the wide application of low-cost ceramic membrane supports.

The potential of catalytic pyrolysis of biomass for hydrogen and bio-oil production has drawn great attention due to the concern of clean energy utilization and decarbonization. In this paper, the catalytic pyrolysis of pine sawdust with calcined dolomite was carried out in a novel moving bed reactor with a two-stage screw feeder. The effects of pyrolysis temperature (700–900 °C) and catalytic temperature (500–800 °C) on pyrolysis performance were investigated in product distribution, gas composition, and gas properties. The results showed that with the temperature increased, pyrolysis gas yield increased, but the yield of solid and liquid products decreased. With the increase in temperature, the CO and H2 content increased significantly, while the CO2 and CH4 decreased correspondingly. The calcined dolomite can remove the tar by 44% and increased syngas yield by 52.9%. With the increasing catalytic temperature, the catalytic effect of calcined dolomite was also enhanced.

The paper describes the research of efficiency of natural and modified sorbents used for purification of industrial sewage from ions of heavy metals (Fe, Cd, Zn, Cu, Cr). Sorbents of various structures are produced on the basis of waste of the mining and processing works (MPW), nonmetallic materials (montmorillonite, dolomite) and modified by humic compounds with thickness of applied layer from 50 nanometers to 100 microns. The choice of structure of the modified sorbents has been determined by the aim to use positive properties of all components as much as possible: their high sorption and regeneration properties. Besides, application of the humic compounds disengaged from peat and waste of brown coal on surface of sorbents caused significantly increased adsorptive activity due to existence of broad set of groups and fragments in structure of humates. These groups and fragments (acid, amino-acid, spirit, carbohydrate, phenolic, amino-keto-alcohol, etc.) form complexes practically with all heavy metals. Use of three main specified components as a part of sorbents resulted in synergetic effect and also allows receiving the highly effective and at the same time inexpensive, rather universal materials with high sorption properties.

The paper presents an aluminum foam experimental technique using the microwave energy. The raw material was recycling aluminum waste processed by ecological melting and gas atomizing to obtain the fine powder required in the foaming process. The powder mixture was completed with dolomite as a foaming agent. The products had a fine and homogeneous porous structure (pore size between 0.4-0.9 mm). The density (1.17-1.19 g/cm3), the compressive strength (6.83-7.01 MPa) and the thermal conductivity (5.71-5.84 W/m·K) had values almost similar to the foams made by conventional methods.

The paper presents an aluminum foam experimental technique using the microwave energy. The raw material was recycling aluminum waste processed by ecological melting and gas atomizing to obtain the fine powder required in the foaming process. The powder mixture was completed with dolomite as a foaming agent. The products had a fine and homogeneous porous structure (pore size between 0.4-0.9 mm). The density (1.17-1.19 g/cm3), the compressive strength (6.83-7.01 MPa) and the thermal conductivity (5.71-5.84 W/m·K) had values almost similar to the foams made by conventional methods.

Using first-principles calculation method and comparing the difference between the free energy, the binding energy and electronic energy, the paper obtained CanOn-1S clusters is possible by the presence of CaO to CaS desulfurization process. Compared with the (CaO) n clusters, CanOn-1S clusters is in the lower energy side and the reaction has a tendency to lower energy spontaneously. As an excessive state, CanOn-1S clusters forms before the nucleation CaS. According to analyze HOMO-LUMO energy difference, its chemical activity is higher than (CaO) n.

Accurate lithofacies-paleogeographic reconstruction is of great significance in predicting the dolomite reservoir distribution of the middle assemblage of Ordovician Majiagou Fm in the Ordos Basin. In this paper, the controlling effects of palaeotectonic background over sedimentation were first analyzed. Then the sedimentary mode of the middle assemblage was established and the lithofacies-paleogeography was reconstructed objectively for three intervals (Ma55, Ma57 and Ma59), based on the observation results of a large number of drilling cores and rock sections, together with the results of logging interpretation of rock composition and structure, single factor maps analysis and seismic data interpretation. The following findings were obtained. First, the middle assemblage of Majiagou Fm presents the uplift-depression alternation; two secondary low uplift zones extending in NS, i.e. Wushen Banner–Wuqi and Shenmu–Yulin–Yan'an, are developed in the eastern side of the central paleo-uplift, between which there is intraplatform depression, and lagoons are deposited in the Mizhi area in the east of the basin. Second, in the Ordos Basin, four NE-trending rift troughs are developed in the Proterozoic, which greatly affects the Ordovician sedimentary pattern and controls the distribution of intraplatform grain banks. Third, influenced jointly by the uplift-depression alternation and the intraplatform rift troughs of the Proterozoic, the intraplatform grain banks in the middle assemblage are mainly developed in the two low uplift zones, i.e. Shenmu–Yulin–Yan'an and Wushen Banner–Wuqi, trending NE in a similar echelon distribution. In conclusion, the two low uplift zones are the main development areas for high-quality carbonate reservoirs within the middle assemblage of Majiagou Fm in the basin.

Abstract The genesis of the fine crystalline dolomites that exhibit good to excellent reservoir properties in the upper fourth member of the Eocene Shahejie Formation (Es 4 s ) around the Sikou Sag, Bohai Bay Basin, is uncertain. This paper investigates the formation mechanisms of this fine crystalline dolomite using XRD, SEM, thin section analysis and geochemical data. The stratigraphy of the Sikou lacustrine carbonate is dominated by the repetition of metre-scale, high-frequency deposition cycles, and the amount of dolomite within a cycle increases upward from the cycle bottom. These dolomite crystals are 2–30 μm in length, subhedral to anhedral in shape and typically replace both grains and matrix. They also occur as rim cement and have thin lamellae within ooid cortices. Textural relations indicate that the dolomite predates equant sparry calcite cement and coarse calcite cement. The Sr concentrations of dolomites range from 900 to 1200 ppm. Dolomite δ18O values (−11.3 to −8.2 ‰ PDB) are depleted relative to calcite mudstone (−8.3 to −5.4 ‰ PDB) that precipitated from lake water, while δ13C values (0.06–1.74 ‰ PDB) are within the normal range of calcite mudstone values (−2.13 to 1.99 ‰ PDB). High 87Sr/86Sr values (0.710210–0.710844) indicate that amounts of Ca2+ and Mg2+ have been derived from the chemical weathering of Palaeozoic carbonate bedrocks. The high strontium concentration indicates that hypersaline conditions were maintained during the formation of the dolomites and that the dolomites were formed by the replacement of precursor calcite or by direct precipitation.

This paper provides strong evidence for the contribution of the phylum Firmicutes in mediating the primary precipitation of Mg-rich carbonates (hydromagnesite, dolomite, magnesite, and nesquehonite) in recent microbialites from a highly alkaline and ephemeral inland lake (Las Eras, Central Spain). The carbonate mineral precipitation occurs sequentially as the microbial mats decay. Scanning electron microscopy (SEM) provided solid proof that hydromagnesite nucleation is initiated on the exopolymeric substances (EPS) and the microbial cells associated to the microbial mat degradation areas. The progressive mineralization of the EPS and bacterial cells by hydromagnesite plate-like crystals on their surface, results in the entombment of the bacteria and formation of radiating aggregates of hydromagnesite crystals. The hydrous phases, mostly hydromagnesite, were produced at a high percentage in the first stages of the microbial degradation of organic matter. When the availability of organic substrates declines, the heterotrophs tend to reduce their number and metabolic activity, remain dormant. At this stage, the anhydrous phases, dolomite and magnesite, nucleate on bacterial nanoglobules and/or collapsed cells. Evidence for the sequential formation of the Mg-rich carbonates trough the decay of organic matter by a fermentative EPS-forming bacterium isolated from the microbialites, Desemzia incerta, is drawn through a comparative analysis of carbonate formation in both natural and experimental settings. This study will help to constrain potential mechanisms of carbonate formation in natural systems, which are of fundamental importance not only for understanding modern environments but also as a window into the geologic past of Earth and potentially Mars.

The paper presents the basic problem related with practical application of carbonate rocks in construction: are carbonate aggregates produced from such rocks favorable for building engineering, particularly for road design and construction? To resolve this problem, (1) the geological-engineering properties of aggregates are presented, (2) the correlation between petrographic and engineering parameters is shown, and (3) a strict correlation between the geological-engineering properties and the freezing-thawing and crushing resistance is recognized. This knowledge has allowed to assess the usefulness of asphalt concrete (AC) made from dolomite and limestone aggregates in the design and construction of road surface structures. The petrography was characterized using optical microscopy and scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscope (EDS). Engineering properties were determined in accordance with European and Polish norms and guidelines. Statistical and design calculations were performed using dedicated software. The petrographic properties, and selected physical and mechanical parameters of the aggregates, were tested to show their influence on the freezing–thawing and crushing resistance. Strong functional relationships between the water adsorption, and the freezing–thawing and crushing resistance have been observed. Aggregate strength decreased after saturation with increasing concentrations of salt solutions. Calculations of AC fatigue durability and deformation allow for reducing the thickness of the road surface structure by about 20% in comparison to normative solutions. This conclusion has impact on the economy of road design and construction, and allows for a rational utilization of rock resources, which contributes to sustainable development of the construction industry.

Some of the more recent methods to produce biodiesel are based on heterogeneous catalysis, which has the advantage of easy separation of catalyst from the final product. In this paper, the heterogeneous transesterification of rapeseed oil with methanol is studied. The aim of this work was to investigate the possibilities of using natural catalysts in biodiesel synthesis and to determine the optimal conditions for this process. After the evaluation of catalytic effectiveness of rocks containing calcium and magnesium carbonates, it was determined that dolomite is the most effective catalyst in heterogeneous biodiesel synthesis. The optimal conditions of dolomite preparation are the following: heating at 850 °C for 5 h. The rapeseed oil transesterification was optimized by the application response surface methodology. Optimal conditions for the production of rapeseed methyl esters using dolomite as catalyst are the following: molar ratio of methanol to rapeseed oil of 11.94:1, reaction temperature of 64 °C, dolomite content of 6 wt%, reaction time of 5 h.

This paper analyzes the influence of sodium phosphate salts with different chain lengths as depressants on the flotation behavior of magnesite and dolomite through single mineral flotation test, contact angle test, and theoretical analysis. Flotation tests show that depressants should be added for the flotation separation of magnesite and dolomite. The inhibition of sodium phosphate salts on dolomite is significantly stronger than magnesite, and the flotation difference of minerals is affected by the chain length of phosphate depressants. The order of flotation separation enhancement of different sodium phosphate depressants is sodium hexametaphosphate ≈ sodium tetrapolyphosphate > sodium tripolyphosphate > sodium pyrophosphate. This result could also be supported by the contact angle measurement.

Confirming thick hydrocarbon generation center and discovering thick porous reservoirs are two key factors to start the Permian gas exploration of the Western Sichuan Depression. In this paper, the Sinian-Cambrian structures of this area were studied by adopting the layer-flattening technology and the Lower Paleozoic thickness map was prepared in order to describe the Permian hydrocarbon generation center. Then, combined with seismic facies analysis and field outcrop bioherm discovery, the distribution of Middle Permian reef flat reservoirs were predicted. Finally, the favorable conditions for reef flat reservoir dolomitization were analyzed based on fault features. The study indicates that: (1) Sinian top represents a huge depression in the profile flatted by the reflecting interface of Permian bottom, with normal faults filled by thick Lower Paleozoic sediments at both sides, revealing that a aulacogen formed during the Khanka taphrogeny exists in the Western Sichuan Depression, where very thick Cambrian strata may contain hydrocarbon generation center, making Permian strata have the material conditions for the formation of large gas pools; (2) the Middle Permian strata in the Western Sichuan Depression exhibit obvious abnormal response in reef flat facies, where three large abnormal bands are developed, which are predicted as bioherm complex combined with the Middle Permian bioherm outcrop discoveries in surface; and (3) deep and large extensional faults are developed in reef flat margin, manifesting as favorable conditions for the development of dolomite reservoirs. The results show that the Middle Permian traps in the Western Sichuan Depression contain resources up to 7400 × 108 m3, showing significant natural gas exploration prospects. By far, one risk exploration well has been deployed.

The Middle Permian system in the Sichuan Basin represents favorable conditions for the formation of natural gas reservoirs. However, only fracture-vuggy limestone gas reservoirs were discovered in early exploration, whose scales and results were limited. In 2014, a high-yield industrial gas flow was produced there in Well Shuangtan 1, the major risk-exploration well, which means a great breakthrough in natural gas exploration in the Middle Permian system, Sichuan Basin. This plays a strategically important and guiding role in oil and gas exploration in ultra-deep marine formations. This paper illustrates the deployment background of Well Shuangtan 1, major exploration achievements and its significance in the gas exploration in the Middle Permian system, Sichuan Basin. Moreover, exploration potential and subsequent exploration targets of Middle Permian are analyzed in terms of its hydrocarbon source conditions, sedimentary characteristics, reservoir characteristics and areal extension, resources and favorable exploration zones. It is concluded that the Middle Permian system in the Sichuan Basin is a continent-connected carbonate platform with carbonate deposits being dominant. There are three types of reservoirs, including pore dolomite, karst fracture-vuggy, and fracture, which present considerable natural gas resources and huge exploration potential. Favorable exploration zones classification of Middle Permian in the Sichuan Basin indicates that the most favorable exploration zones are mainly distributed in the central-western Sichuan Basin. In particular, the northwestern Sichuan Basin is the most favorable exploration area which is characterized by the most excellent hydrocarbon source conditions, developed dolomite reservoirs and zonal distribution of structures.

Surface roughness has an important influence on the wettability of particles. This paper is an innovative exploration to control the surface wettability of apatite and dolomite from the perspective of roughness in the background of phosphate flotation. Roughness characteristics of apatite and dolomite particles and its effects on wettability were investigated with surface roughness, contact angle measurements, and SEM analysis. The relationship between surface energy and wettability of different roughness surfaces was also discussed. The results indicated that the influence of roughness on apatite and dolomite particles showed the same regularity, and wettability increased with the increasing roughness for hydrophilic surfaces, while the wettability decreased for hydrophobic surfaces. The influence of roughness on wettability can be well explained by Wenzel and Cassie models, and the surface energy of different rough surfaces had a strong correlation with their wettability. When sodium oleate was added after acid treatment, the apatite was hydrophilic, while the dolomite was hydrophobic; the difference in wettability between them became greater as surface roughness increased. Thus, it can be predicted that the selective separation of dolomite and apatite under acid reverse flotation conditions can be strengthened by increasing the mineral surface roughness during comminution.

This paper deals with the solubilization behavior of the tailings produced by the floatation of a complex low grade phosphate ore. The composition of the tailings was essentially dolomite (52.04%) with minor amounts of phosphate, iron and aluminium oxides (10.4 and 0.5% respectively). The presence of these products created uncontrolled land pollution and severely affected groundwater. An initiative has been taken up for utilization of this waste to generate an eco-friendly product. First step towards this panorama is incorporation of suitable microorganisms for the biodegradation of this effluent. Sulphur oxidizing bacteria Acidithiobacillus thiooxidans produces sulphuric acid which neutralizes the dolomitic tailings and convert it into plant available forms. The solubilization activity was tested in sulphur medium with 5, 10, 15 and 20% concentration of tailings. The solubilization is graded on the basis of pH, Electrical conductivity (EC), soluble calcium and magnesium and soluble phosphate. The results from ex-situ experiments showed that the treatment with 15% tailings ended with highest solubilization. The values of pH, EC, soluble calcium and magnesium and soluble phosphate for this treatment were 4.92, 31.6 dS/m, 10.8 mL EDTA and 17.24 µg/mL respectively. Also, the results proved that sulphur oxidizing bacteria Acidithiobacillus thiooxidans is capable of solubilizing dolomitic tailings from the Jhamarkotra mines. Finally, an important factor taken into account was solubilization of residual phosphate along with dolomite in the tailings. This combined action affects the solubilization behaviour of the residue, which was also showed successfully with the assayed laboratory studies.

In the present paper, we examine the influence of micrite types, autochthonous or allochthonous, on the dolomitization processes. The recrystallized and dolomitized Carnian samples from Rifugio Vallandro and Alpe di Specie erratic boulders (South Tyrol, Italy) offer a unique example for studying the relationship between microbialites and dolomitization processes. The comparison between the carbonates of the well-preserved erratic boulders of Alpe di Specie and the isochronous, recrystallized, and dolomitized, samples of Rifugio Vallandro, allows for hypothesizing the role of microbialites on dolomitization processes. The Rifugio Vallandro samples represent variously dolomitized boundstone (made of corals, sponges, and peloidal crusts) with a fine texture (aphanodolomite) which contain organic matter relics, suggesting microbial-mediated mineralization. Geomicrobiological characterization of the microbialites from Alpe di Specie indicates that they formed through microbial metabolic activity of sulfate-reducing bacteria, which thrive on organic matter accumulated in the suboxic to anoxic interspaces of the skeletal framework. Similar processes can be hypothesized for the microbialite precursor of Rifugio Vallandro. Extracellular polymeric substance (EPS) and other organic compounds trapped inside the fine crystal matrix can have a role in the dolomitization processes of the microbialites. High pH and high alkalinity, derived from the degradation of organic matter, may be critical in promoting the dolomitization of microbialites because the high pH increases the concentration and activity of the dissolved CO32−, thereby increasing the dolomite supersaturation and reaction rates. This process produces very fine dolomite (aphanodolomite) that replaces the original organic-rich micrite, while the fine crystalline dolomite forming larger euhedral crystals seems to derive from the allochthonous micrite due to the presence of a large amount of siliciclastics and the absence of organic remains.