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Palygorskite is an aluminum and magnesium silicate characterized by its fibrous morphology, providing it with great versatility in industrial applications, including pharmaceuticals. Although most of the reserves are in the United States, in recent years occurrences of commercially exploited deposits in Brazil have been recorded, mainly in the country's northeast region. This has motivated this study, which analyzes raw Brazilian palygorskite compared to a commercial sample (Pharmasorb® colloidal) to demonstrate its pharmaceutical potential. The chemical and mineral composition of the samples were evaluated for surface properties, granulometry, morphology, crystallography, thermal analysis, and spectroscopy. Raw palygorskite presented 67% purity, against 74% for Pharmasorb® colloidal. The percentage purity relates to the presence of contaminants, mainly carbonates and quartz (harmless under conventional conditions of pharmaceutical use). Furthermore, it was possible to confirm the chemical composition of these phyllosilicates, formed primarily of silicon, aluminum, and magnesium oxides. The crystallographic and spectroscopic profiles were consistent in both samples, showing characteristic peaks for palygorskite (2θ = 8.3°) and bands attributed to fibrous phyllosilicates below 1200 cm−1, respectively. The thermal analysis allowed the identification of the main events of palygorskite, with slight differences between the evaluated samples: loss of water adsorbed onto the surface (~85 °C), removal of water contained in the channels (~200 °C), coordinated water loss (~475 °C), and, finally, the dehydroxylation (>620 °C). The physicochemical characteristics of raw palygorskite align with pharmacopeial specifications, exhibiting a high specific surface area (122 m2/g), moderately negative charge (−13.1 mV), and compliance with the required limits for heavy metals and arsenic. These favorable technical attributes indicate promising prospects for its use as a pharmaceutical ingredient in the production of medicines and cosmetics. [ABSTRACT FROM AUTHOR]

Soybean is one of the main agricultural species cultivated in Brazil, but it may have reduced yield due to the incidence of pests and diseases. This study aimed to evaluate the effect of silicon spray at different soybean phenological stages on the severity of Asian rust (AR), the soybean caterpillar population, and the yield of soybean. The experiment was conducted in the 2012/2013 crop season through a randomized complete block with five replications and factorial scheme (2x5). The factors were two soybean cultivars (Anta 82 RR and CD 2737 RR) and five treatments for AR management (T1-negative control; T2-aluminum silicate in R1 + R4; T3-aluminum silicate in V5 + R1 + R4; T4-aluminum silicate in V5 + R1 + R4 + R5.1; and T5-positive control: trifloxystrobin + prothioconazole in R1 + R4). Defoliation, disease severity, area under the disease progress curve (AUDPC) and yield were evaluated. Soybean caterpillar population was monitored weekly using a beating sheet. Sprays of aluminum silicate reduced the severity of AR and AUDPC in relation to the control, but it was less effective than the positive control. Grain yield increased when three and four aluminum silicate sprays were performed, and the population level of soybean caterpillars was not reduced by silicon. [ABSTRACT FROM AUTHOR]

Abstract: To investigate the effect of the soil passage through the gut of earthworms (Pontoscolex corethrurus) on the forms of Pb and Mn, casts and soil samples were analyzed by sequential extraction procedure. Soil samples were collected in an area under direct influence of mining and metallurgy of Pb in the Parana state, Brazil. The earthworms were incubated with the soils to collect castings. The Pb and Mn concentrations were determined in seven sequential phases: soluble; exchangeable; carbonate; organic matter; Fe and Mn oxides; Al oxides and aluminosilicates; residual. There was intense contamination with Pb in the area, mainly in the clayish soil surrounding the factory by the deposition of suspended material coming from the chimneys (maximum concentration 9716 mg kg−1). On the other hand, total concentration of soil Mn was little influenced by the mining and metallurgy activities in the area. The earthworms significantly reduced the amount of Pb in the soluble and exchangeable forms in the soil, considered environmentally more bioavailable. There was also a significant increase in Pb bound in Fe and Mn oxides in the casts (specific absorption), which is desirable for soil bioremediation. [Copyright &y& Elsevier]

The article presents a study that evaluates the physical, chemical and mineralogical characteristics of the kaolin wastes processed from Capim and Jari region in Brazil. It explores the method of the study that uses X-ray diffraction analysis, differential thermal analysis, and infrared spectroscopy to accurately determine the components of the element. The result of the study indicates that kaolin wastes can be good raw materials for the production of high reactive metakaolin.

Carbon dioxide-rich fluid and carbonate-rich aluminosilicate melt inclusions in tantalite-(Mn) from the Alto do Giz pegmatite in the Borborema Pegmatite Province, northeastern Brazil were investigated to constrain the formation of the host crystals. The results demonstrate that in the Alto do Giz pegmatite, water- and alkaline carbonate-rich fluids and melts are responsible for the transport and deposition of tantalite-(Mn) at temperatures around 600°C and about 4 kbar. Moreover, evidence is presented to show that during crystallization of the tantalite-(Mn), three different components coexisted, which are now trapped as separate inclusions: two immiscible silicate melts (types A and B melt inclusions) and a CO-rich aqueous fluid. We hypothesize that immiscible fluid separation may have been a critical factor in producing the water- and alkaline carbonate-rich fluids and melts necessary for Ta and Nb transport. Since the tantalite-(Mn) crystallized during pegmatite formation, this mechanism must also have implications for pegmatite genesis in general. [ABSTRACT FROM AUTHOR]

The research presents a study conducted to address the second stage, binary mixtures of clays Ceramic Santa Rita and the Cooperative of Artisans from Foz do Iguacu, Brazil, in different weight percentages, for making specimens by uniaxial pressing. Proportions of 4, 8, 12 and 16% of the waste sludge were added in order to add mass in compositions among the clays that were better at processing.

Air pollution caused by the lime production industry has become a serious problem with potential effects to human health, especially in developing countries. Colombo is a city included in the Metropolitan Region of Curitiba (capital of Paraná State) in South Brazil. In Colombo city, a correlation has been shown between the lime production and the number of persons who need respiratory treatment in a local hospital, indicating that the lime industry can cause deleterious health effects in the exposed workers and population. This research was conducted to deal firstly with the characterization of the size distribution and chemical compositions of particles emitted from lime manufacturing and subsequently to assess the deposition rate of inhaled dolomitic lime aerosol particles in the human respiratory tract. The elemental chemical composition and particle size of individual atmospheric particles was quantitatively elucidated, including low-Z components like C, N and O, as well as higher-Z elements, using automated electron probe microanalysis. Information concerning the bulk composition is provided by energy-dispersive X-ray detection. The majority of the respirable particulate matter identified was composed of aluminosilicates, Ca–Mg oxides, carbon-rich particles, mixtures of organic particles and Ca–Mg carbonates, soot and biogenic particles. In view of the chemical composition and size distribution of the aerosol particles, local deposition efficiencies in the human respiratory system were calculated, revealing the deposition of CaO·MgO at extrathoracic, tracheobronchial and pulmonary levels. The results of this study offer evidence to the threat of the fine and coarse particles emitted from dolomite lime manufacturing, allowing policy-makers to better focus their mitigation strategies in an effective way, as well as to the dolomite producers for the purpose of designing and/or implementing improved emission controls. [Copyright &y& Elsevier]

Four sand pit lakes, at the Rio de Janeiro Sand Mining District, were monitored from November 2003 to November 2005, in order to characterize their hydrogeochemistry aiming to provide information to their possible use as fishponds at the end of mining activities. The results show diluted waters (low electrical conductivity) with low pH (<4) and relatively high sulfate and aluminum concentrations. The major water components (in particular Fe, Mn, SiO2, Al and SO4) are related to water acidity, since it controls solubility of aluminum silicate minerals and Mn and Fe oxides. Fe, Mn and Al availability in these waters are probably associated to organic colloids formation. On the other hand, the SiO2 content, as well as the decrease of sand mining in rainy season, may partially control Al availability by the formation of hydroxi-aluminum silicates. These geochemical processes together with the interruption of sand mining in the rainy season and the dilution of sand pit lakes water by rainwater can support the use of these pit lakes as fishpond for aquaculture. [ABSTRACT FROM AUTHOR]

High-quality kaolins are produced from two sites in the Capim River area in Pará State, northern Brazil. One mine is operated by Rio Capim Caulim (RCC) owned by Imerys and the other by Pará Pigmentos S.A. (PPSA) owned by Caemi (CVRD Group). The kaolin deposits are located on low-relief plateaux with a lateritic cap. The kaolin strata are in the Ipixuna Formation of Upper Cretaceous Age. There are two distinct kaolin layers, a 4–5 m thick soft kaolin which is overlain in the southern portion of the basin by a 4–5 m thick hard kaolin. The soft and hard designations refer to particle size, with the soft kaolin being relatively coarse and the hard kaolin very fine. The kaolin is mined, partially beneficiated, and pumped through pipelines to the port at Barcarena on the Guama River, a large tributary of the Amazon River. The PPSA kaolin is fully processed at the plant near the mine site and pumped to Barcarena where it is spray dried. The RCC kaolin is only partially processed at the mine site. This partially processed kaolin is pumped to Barcarena where it is beneficiated. The finished kaolin is high quality and is shipped to North and South American, European, and Asian paper-coating markets. More than 1.6M tons were shipped from Barcarena in 2005. [ABSTRACT FROM AUTHOR]

Abstract: Widespread intensive land use in the seasonal tropics can damage the physical stability of aggregates. Similar damage can be expected from wetting and drying cycles causing aggregate fragmentation and, consequently, leading to an increase in their specific area and exposure of internal electric charges. Thus, we hypothetised that the influence of wetting and drying cycles is dependent on the mineralogical composition of oxisols (latosols) and it is higher in soils with low aggregate stability. A greenhouse experiment was carried out to test this hypothesis in highly weathered soils from Brazil, all with variable-charge clays and highly stable aggregates. Wetting and drying cycles were defined from the quantity of water available between field capacity and the permanent wilting point. Soil columns were submitted to 0, 2, 6, 9, 12, 15 and 18 wetting and drying cycles. After each number of wetting and drying defined physical and chemical properties were determined. Statistical analysis, such as simple and multiple linear regression and Pearson''s correlation were performed, showing significantly correlated WDC contents with wetting and drying cycles. The obtained results led to the conclusion that there was a close interdependence among mineralogical composition, aggregate stability and WDC influenced by wetting and drying cycles. Soils of reduced aggregate stability like kaolinitcs made them more susceptible to the action of wetting and drying on the WDC. Changes in the WDC with wetting and drying cycles showed correlated with eletrochemical properties. [Copyright &y& Elsevier]

Abstract: This work presents the results of a study concerning the processing of red wall tile composed of clay, calcareous, and quartz from Brazil. The formulation prepared by dry process was optimized depicting the effect of the calcareous addition (12–18mass%) on the densification behaviour during the firing process. The samples were unidirectionally dry pressed in a die with rectangular cavity and fired in air at temperatures ranging from 1080 to 1200°C using a fast-firing cycle. The samples were characterized before and after firing. The development of the microstructure was followed by XRD and SEM. The densification was measured by three parameters: linear shrinkage, water absorption, and flexural strength. The results revealed that the red wall tile bodies containing abundant calcareous fired above 1000°C form gehlenite and anorthite. Moreover, the densification behaviour was found to be influenced by the calcareous content and sintering temperature. The microstructure is constituted of a network of small dense zones interconnected with a porous phase. It was also found that the requirements specified in the Brazilian tile standards concerning the BIII class tiles were fulfilled, depending on calcareous content and sintering temperature. [Copyright &y& Elsevier]

During the industrial processing of kaolin, the ore material is submitted to bleaching treatments with sulfuric and phosphoric acids and metallic zinc, in order to remove colored iron-rich minerals. The effluent waste is initially strongly acidic, and is chemically neutralized with calcium oxide and left to dry in open pits dug out in the terrain surrounding the industrial plant. The dried residue is then accumulated in deposits so as to produce the “solid reject”. The Fe in these reject deposits precipitates as poorly crystalline iron-bearing compounds, which are difficult to identify by conventional X-ray diffraction techniques, and must be further characterized by complementary 57Fe Mössbauer analysis. 298 and 80 K Mössbauer spectra of the whole sample collected from the solid reject deposit of the Caolim Azzi industrial plant, in the city of Mar de Espanha, MG, Brazil, revealed that Fe3+ is mainly in octahedral sites of silicates. After treating this whole sample with NaOH, the Mössbauer parameters at 298 and 80 K indicated mainly the presence of iron oxide (hematite; ideal formula, αFe2O3) and oxyhydroxides, such as lepidocrocite (γFeOOH), goethite (αFeOOH) and iron hydroxysulphate, as jarosite (MFe3(SO4)2(OH)6; M = mono or divalent cation). [ABSTRACT FROM AUTHOR]

In order to evaluate the metal contamination from kaolin industry discharges into rivers in the State of Minas Gerais, Brazil, samples of river water and fluvial sediment were collected up- and down-river from the industries and analysed to detect metal inputs. The metal examined included zinc, iron, and aluminium among others, being selected due to their toxicity and occurrence in waste waters. Metal inputs in the samples analysed appeared to be related to effluent discharges into the rivers. The river water showed high concentrations (in μg mL-1) of Zn (355), Fe (354) and Al (303). Sediment investigations indicated heavy enrichment (SEF = 9.4) for Zn. The Geoaccumulation Index for this element accounted for 3 (moderately to heavy polluted). River water pH of the sample collected near the effluent discharge site reached 3.7, suggesting inadequate treatment. [ABSTRACT FROM AUTHOR]

Musca domestica L. is a cosmopolitan nuisance of high sanitary importance. Entomopathogenic fungi are innovative and attractive tools for integrated control of the housefly to overcome insufficient levels of control caused by increasing resistance of this pest against chemical insecticides. High virulence of a fungal strain is a prerequisite to develop a mycoinsecticide, and the present study investigated the potential of hypocrealean fungi from the genera Beauveria, Clonostachys, Cordyceps, Akanthomyces, Metarhizium, and Tolypocladium, isolated from mosquitoes in Central Brazil against M. domestica. The highest mortalities (larvae, pupae, and adults) were caused by Metarhizium humberi IP 478 (98%) and IP 421 (90%), Metarhizium anisopliae IP 432 (85%), Beauveria bassiana IP 433 (82%), and Tolypocladium cylindrosporum IP 425 (68%) after a 23-day exposure of initially pre-pupating third instar larvae to conidia mixed with vermiculite. Lethal concentrations to kill 90% of adults of IP 433 and IP 478 were 5 × 10 7 and 10 8 conidia g -1 substrate, respectively. Fifty percent of adults were killed within 4 to 5 days of exposure initially as pupae close to emergence to substrate treated with conidia of IP 478 or IP 433 at 1.1 × 10 8 conidia g -1 , respectively. The other fungal strains tested were less virulent. The results demonstrate high potentials for conidial preparations in vermiculite of IP 433 and IP 478 as candidates for the biological control of both pre-pupating larvae, pupae, and emerging adults of houseflies., (© 2022. Sociedade Entomológica do Brasil.)

The article discusses the gemological properties of the small selection of faceted light bluish green kyanites obtained by Luciana Barbosa of the Gemological Center in Minas Gerais, Brazil, and were shown at the 2005 Tucson gem shows. Included in each stone was a single, transparent, dark yellowish brown crystal, which was well-formed with chisel-point terminations and a diamond-shaped cross-section. Barbosa stated that the inclusions were pseudo-orthorhombic crystals of staurolite, a monoclinic iron-aluminum silicate.

This study aimed to evaluate the sorption-desorption and leaching of aminocyclopyrachlor from three Brazilian soils. The sorption-desorption of 14 C-aminocyclopyrachlor was evaluated using the batch method and leaching was assessed in glass columns. The Freundlich model showed an adequate fit for the sorption-desorption of aminocyclopyrachlor. The Freundlich sorption coefficient [K f (sorption) ] ranged from 0.37 to 1.34 µmol (1-1/n) L 1/n kg -1 and showed a significant positive correlation with the clay content of the soil, while the K f (desorption) ranged from 3.62 to 5.36 µmol (1-1/n) L 1/n kg -1 . The K f (desorption) values were higher than their respective K f (sorption) , indicating that aminocyclopyrachlor sorption is reversible, and the fate of this herbicide in the environment can be affected by leaching. Aminocyclopyrachlor was detected at all depths (0-30 cm) in all the studied soils, where leaching was influenced by soil texture. The total herbicide leaching from the sandy clay and clay soils was <0.06%, whereas, ∼3% leached from the loamy sand soil. The results suggest that aminocyclopyrachlor has a high potential of leaching, based on its low sorption and high desorption capacities. Therefore, this herbicide can easily contaminate underground water resources.

The quality of recycled aggregates from construction and demolition waste (CDW) is strictly related to the content of porous and low strength phases, and specifically to the patches of cement that remain attached to the surface of natural aggregates. This phase increases water absorption and compromises the consistency and strength of concrete made from recycled aggregates. Mineral processing has been applied to CDW recycling to remove the patches of adhered cement paste on coarse recycled aggregates. The recycled fine fraction is usually disregarded due to its high content of porous phases despite representing around 50% of the total waste. This paper focus on laboratory mineral separability studies for removing particles with a high content of cement paste from natural fine aggregate particles (quartz/feldspars). The procedure achieved processing of CDW by tertiary impact crushing to produce sand, followed by sieving and density and magnetic separability studies. The attained results confirmed that both methods were effective in reducing cement paste content and producing significant mass recovery (80% for density concentration and 60% for magnetic separation). The production of recycled sand contributes to the sustainability of the construction environment by reducing both the consumption of raw materials and disposal of CDW, particularly in large Brazilian centers with a low quantity of sand and increasing costs of this material due to long transportation distances., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

The interaction between the Brazilian pioneer legume Sesbania virgata and its microsymbiont Azorhizobium doebereinerae leads to the formation of nitrogen-fixing nodules on roots that grow either in well-aerated soils or in wetlands. We studied the initiation and development of nodules under these alternative conditions. To this end, light and fluorescence microscopy were used to follow the bacterial colonisation and invasion into the host and, by means of transmission electron microscopy, we could observe the intracellular entry. Under hydroponic conditions, intercellular invasion took place at lateral root bases and mature nodules were round and determinate. However, on roots grown in vermiculite that allows aerated growth, bacteria also entered via root hair invasion and nodules were both of the determinate and indeterminate type. Such versatility in entry and developmental plasticity, as previously described in Sesbania rostrata, enables efficient nodulation in both dry and wet environments and are an important adaptive feature of this group of semi-tropical plants that grow in temporarily flooded habitats., (© 2012 German Botanical Society and The Royal Botanical Society of the Netherlands.)

A challenge of metagenomic studies is in the extraction and purification of DNA from environmental samples. The soils of the Cerrado region of Brazil present several technical difficulties to DNA extraction: high clay content (>55% w/w), low pH (4.7) and high iron levels (146 ppm). Here we describe for the first time the efficient recovery and purification of microbial DNA associated with these unusual soil characteristics and the construction and validation of two metagenomic libraries: a 150,000 clones library with insert size of approximately 8 kb and a 65,000 clones library with insert size of approximately 35 kb. The construction of these metagenomic libraries will allow the biotechnological exploitation of the microbial community present in the soil from this endangered biome.