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The paper presents the results of experimental study of the adsorption characteristic of the IM-50 and tall oil fatty acids (TOFA) collector reagents on cassiterite. UV-spectrophotometric method, scanning electron and laser microscopy were applied to analyze the adsorption of the reagents. SHIMADZU UV 1800 was used to obtain the UV spectra of aqueous solutions of IM-50 reagents and saponified TOFA at varied concentrations. IM-50 has not got characteristic adsorption maxima in ultraviolet and visible spectrum. TOFA has a weakly pronounced maximum absorption in the range of 233-244 nm. Microscopic photographs of cassiterite sections were obtained with LEO 1420VP INCA equipped OXFORD ENERGY 350 analyzer. Reagent IM-50 and TOFA collector reagent, Newly formed organic matter phases of IM-50 and TOFA were detected. X-ray spectra characterized the increased carbon content indicating adsorption on the surface of cassiterite IM-5- and TOFA. By measuring the surface relief parameters of polished cassiterite, using KEYENCE VK-9700 scanning laser microscopy and VK-Analyzer software, a qualitative and quantitative assessment of the IM-50 and TOFA reagent layer on the cassiterite surface was performed. Measurements were performed in the several fields of view and showed the degree of IM-50 coating varied from 40.5 to 42.6% of the surface area, and TOFA average coating was 38.5%. Subsequent washing with water does not remove the reagents from the surface of the mineral and indicates a strong fixation of IM-50 and TOFA on cassiterite, which can have a positive effect on flotation extraction of sludge tin fractions. Qualitative and quantitative results of the reagent adsorption helped to make a forecast of their floatability by the studied collectors. This study is supported by the Russian Science Foundation (project No. 17-17-01292). [ABSTRACT FROM AUTHOR]

The Huanggang iron–tin polymetallic skarn deposit is located in the southern Great Xing'an Range. According to the ore types and mineral assemblages, the paragenetic sequence of the Huanggang deposit can be divided into three stages, and these magnetite grains were mainly formed at the retrograde and sulphide skarn stages. The magnetite (sample HG12‐13) from the early retrograde stage is represented by fine‐grained magnetite cutting across coarse‐grained magnetite surrounded by quartz and calcite. The magnetite (sample HG12‐73) from the late retrograde stage is locally replaced by haematite along the margin or interior and is surrounded by calcite. The magnetite (sample HG12‐88) from the early sulphide stage is characterized by obvious core–rim textural features. The magnetite (sample HG‐62) from the late sulphide stage is featured by zone‐like magnetite occurring along the margin and interior of the primary magnetite. Laser ablation inductively coupled plasma mass spectrometry was used to obtain trace element concentrations of magnetite from the different mineralization stages in order to better understand the geochemical variations in the ore‐forming process. Some magnetite grains have abnormally high Mg, Al, K, Cu, Zn, and Sn due to the presence of numerous inclusions (e.g., chlorite, sylvite, chalcopyrite, sphalerite, and cassiterite). In general, magnetite grains from the different mineralization stages demonstrate similar bulk continental crust normalized trace elements patterns, suggesting that they share a similar origin. The increasing Si + Al/Mg + Mn ratios and decreasing Mg + Mn contents for magnetite show an increasing fluid–rock ratio from the retrograde to sulphide stage. Co contents of magnetite decrease abruptly from the retrograde stage to the sulphide stage, whereas Mn contents show the reverse trend, which is affected by minerals coprecipitating with magnetite. A zoned magnetite from the sulphide stage shows decreasing Ti and V contents from core to outer rim; the variation of Ti and V may be related to the temperature or oxygen fugacity. Magnetite compositions from the Huanggang deposit are similar to those from Fe, Cu‐polymetallic, or other skarn deposits, but display more variable compositions than previously presented. Our study demonstrates that the evolution of magnetite in the skarn deposit and trace element of magnetite could be a powerful tool in determining the origin of skarn iron deposit. [ABSTRACT FROM AUTHOR]

The southwestern South China Block, composed of southwestern China and northeastern Vietnam, is one of the most important Sn-polymetallic ore districts in the world. The Dulong skarn Sn-polymetallic deposit, which is closely related to Late Cretaceous granitic magmatism, contains 5.0 mt Zn, 0.4 mt Sn, 0.2 mt Pb, and 7 kt In, and is one of the largest Sn-polymetallic deposits in the region. Sn mineralization occurs mainly as cassiterite at the contact zone between the Laojunshan granitic pluton and carbonates of the Cambrian Tianpeng Formation. The Laojunshan granitic pluton consists of three: medium- to coarse-grained two-mica monzonitic granite, medium- to fine-grained two-mica monzonitic granite, and granite porphyry, with zircon U–Pb ages of 87.5 ± 0.6 Ma, 85.3 ± 1.1 Ma, and 82.8 ± 1.6 Ma, respectively. Zircon grains from these three phases show ε Hf (t) values from −9.5 to −2.5, typical of a mantle origin. All samples exhibit strongly peraluminous and high-K calc-alkaline affinities, and show trace element patterns characterized by enrichment in Rb, Ta, La, Zr, and Hf, and depletion in Ba, Nb, and Ti, typical of S-type granites. Three main alteration/mineralization stages are recognized within the mineralized contact zones: (1) skarn stage; (2) sulfide mineralization stage; and (3) supergene stage. Cassiterite grains from the skarn alteration stage yield a 207 Pb/ 206 Pb– 238 U/ 206 Pb concordia age of 89.4 ± 1.4 Ma, suggesting that mineralization was associated with the Laojunshan granitic pluton. Regionally, the Sn-polymetallic mineralization in the southwestern South China Block took place within a narrow time span from 97 to 79 Ma. The causative granitic magmas can be produced by partial melting of the Paleoproterozoic–Mesoproterozoic pelitic basement rocks during large-scale lithospheric thinning and asthenospheric upwelling. [ABSTRACT FROM AUTHOR]

The recently discovered Sanjiaowo Sn deposit is located in eastern Guangdong, SE China. The Sn mineralization, hosted in granite porphyry and the Lower Jurassic Jinji Formation low-grade metamorphic wall rocks, is considered to be granite-related. Zircon U–Pb dating of the granite porphyry yielded concordant ages of 140.5 ± 1.4 Ma, which is consistent with the cassiterite U–Pb age of 139.8 ± 5.0 Ma, indicating a temporal link between the emplacement of granitic plutons and Sn mineralization. The granite porphyry samples are weakly peraluminous and show an A-type geochemical signature with high Na 2 O + K 2 O (7.19–8.51 wt.%), REE (261–308 ppm), Zr + Nb + Ce + Y (353–476 ppm) contents, FeO T /MgO (0.93–0.99), and Ga/Al (2.65–3.42) ratios. They display bulk rock initial 87 Sr/ 86 Sr of 0.7110 to 0.7165, εNd(t) of −5.90 to −4.04, and zircon εHf(t) values from −8.36 to −4.16 with Mesoproterozoic T DM2 ages for both Nd and Hf isotopes. Detailed elemental and isotopic data suggest that the Sanjiaowo Granite porphyry belongs to the A 2 -subtype and were formed by partial melting of a crustal source of Mesoproterozoic overall residence age with minor input of mantle materials. The low calculated zircon Ce 4+ /Ce 3+ (6.5–81.2) and Eu N /Eu N ∗ (0.05–0.24) ratios demonstrates that the Sanjiaowo granitic magma had a low oxygen fugacity, which may have facilitated the Sn enrichment and played a key role in the Sn mineralization. Lead isotopes indicate that there is no difference for 206 Pb/ 204 Pb, 207 Pb/ 204 Pb, and 208 Pb/ 204 Pb ratios between the granite porphyry and the sulfide minerals from the orebodies. Moreover, the sulfur isotopic compositions for the sulfides (pyrite and pyrrhotite: δ 34 S = −1.6–1.0‰, average = −0.32) is similar to magmatic δ 34 S, but different from the δ 34 S in the Jinji Formation strata. Consequently, these data favor of a magmatic-hydrothermal origin for the Sn mineralization in the Sanjiaowo deposit. Integrating new and published data on the tectonic evolution, we suggest that the granite porphyry and associated Sn mineralization in the Sanjiaowo deposit formed in a back-arc extensional environment at ∼141 Ma, related to the rollback of the paleo-Pacific Plate. [ABSTRACT FROM AUTHOR]

The proven global tin reserves were reported to be approximately 4.7 million tons (Mts) in 2016, and among these resources, only approximately 2.2 Mts can be recovered economically. The original tin deposits will be exhausted in several years, therefore, tin-bearing secondary resources, such as tin alloy, tin anode slime, e-wastes, tin slag and tin-bearing tailings, will become the primary source from which tin can be extracted. Many investigations have been conducted on the recovery of tin from these tin-bearing materials. However, the separation and recovery approaches of tin vary significantly, since the content and phase compositions of tin are totally different in these secondary resources. This paper reviews these methods of extracting and separating tin from different kinds of tin-bearing secondary resources. [ABSTRACT FROM AUTHOR]

The recently discovered Jinkeng deposit, located in eastern Guangdong Province, SE China, is a granite-related cassiterite–sulfide-type Sn–Cu–Pb–Zn deposit in the Cathaysia Block. Zircon U–Pb dating of the biotite granite and fine-grained granite associated with the deposit yielded concordant ages of 144.7 ± 0.8 Ma and 141.1 ± 1.3 Ma, respectively. These ages are consistent, within error, with the molybdenite Re–Os isochron age of 139.3 ± 2.5 Ma for the deposit, indicating a temporal link between the emplacement of granitic plutons and polymetallic Sn mineralization. Combined with the regional mineralization ages, we propose that the 145–135 Ma interval represents another significant period of Sn–W mineralization in southern China, in addition to those already recognized. The biotite granite and fine-grained granite have similar geochemical characteristics; both are weakly peraluminous, high-K and calc-alkaline, containing abundant Si, Na, and K, and low concentrations of Fe, Mg, Ca, and P. Compared to primitive mantle and unfractionated granitoids, they are enriched in Rb, Th, U, K, and Pb, have relatively high Rb/Sr and low K/Rb values, are depleted in Ba, Sr, and Ti, and have prominent negative Eu anomalies (δEu = 0.05–0.19), characteristic of highly fractionated I-type granites. Zircons from these granites have ε Hf (t) values ranging from − 9.2 to − 3.3, and Hf model ages (T DM2 ) of 1776–1406 Ma, suggesting that the granites formed by the partial melting of Proterozoic basement material, and contain a minor mantle-derived component. Highly fractionated and reduced ( f O 2 below NNO) magma facilitated the enrichment of Sn. Existing knowledge on the tectonic evolution of this region and new data from this study, indicate that the granites and associated Sn mineralization in the Jinkeng deposit formed in an extensional environment at ~ 140 Ma, likely related to the rollback of the paleo-Pacific Plate. [ABSTRACT FROM AUTHOR]

The Gejiu tin-copper polymetallic ore field, located at the westernmost end of the Cathaysia Block in South China, is one of the largest tin polymetallic ore fields in the world. It is associated with magmatic-hydrothermal ore-forming processes triggered by deeply seated structures and concealed granites. The Bi-dimensional empirical mode decomposition (BEMD) was used to decompose gravity data covering an area including the Gejiu tin-copper polymetallic ore field in the west and the Bozhushan silver-lead-zinc polymetallic ore field in the east, which yielded three two-dimensional intrinsic mode function (BIMFs) images and one residue ( Res ( m , n )) image that depict four layers of geological architectures at different wavelengths within the study area. The high-pass filtered gravity component image (BIMF 1 ) is interpreted to depict the shallow geological architecture, which indicates that the skarn alteration and tin-copper mineralization with positive gravity anomalies are distributed around the granites characterized by negative gravity anomalies. The band-pass filtered gravity component image (BIMF 2 ) is interpreted to depict the middle-shallow geological architecture, which indicates that the outcropped granites in the western Gejiu ore field bounded by the Gejiu fault may extend to the eastern Gejiu ore field to form one integrated granitic complex in the subsurface. The other band-pass filtered gravity component image (BIMF 3 ) is interpreted to depict the middle-lower geological architecture, which indicates that there may be an EW-trending granite zone with negative gravity anomaly at middle-lower depth connecting the Gejiu tin-copper polymetallic field to the Bozhushan silver-lead-zinc polymetallic field, displaying the existence of an EW-trending regional polymetallic ore-forming zone within the study area. The low-pass filtered gravity component image ( Res ( m , n )) is interpreted to depict the lowest geological architecture within the study area, which reflects that there may be a pair of the NW-trending uplift zone of the mantle and/or the basement with positive gravity anomaly and the depression zone of the mantle and/or the basement with negative gravity anomaly. The Gejiu tin-copper polymetallic deposits and the related granites are located at the transitional zone between the uplift and depression, whereas the Bozhushan silver-lead-zinc polymetallic deposits and the related granites are situated within the depression zone, which implies that the diversity of the Late Yanshanian granites and the related polymetallic deposits in the study area may be controlled by the complexity of the crust-mantle interaction at depth. [ABSTRACT FROM AUTHOR]

Monazite [(Ce,Th)PO4] from the Llallagua tin ore deposit in Bolivia is characterized by low radiogenic element contents. Previously reported field evidence and mineral associations suggest the mineral formed via direct precipitation from hydrothermal fluids. Monazite compositions thus may provide insight into characteristics of the fluids from which it formed. Chemical compositions of three Llallagua monazite grains were obtained using Electron Probe Microanalysis (EPMA, n = 64) and laser ablation mass spectrometry (LA-ICP-MS, n = 56). The mineral has higher amounts of U (123 ± 17 ppm) than Th (39 ± 20 ppm) (LA-ICP-MS, ±1σ). Grains have the highest amounts of fluorine ever reported for monazite (0.88 ± 0.10 wt %, EPMA, ±1σ), and F-rich fluids are effective mobilizers of rare earth elements (REEs), Y, and Th. The monazite has high Eu contents and positive Eu anomalies, consistent with formation in a highly-reducing back-arc environment. We speculate that F, Ca, Si and REE may have been supplied via dissolution of pre-existing fluorapatite. Llallagua monazite oscillatory zoning is controlled by an interplay of low (P + Ca + Si + Y) and high atomic number (REE) elements. We suggest monazite compositions provide insight into fluid geochemistry, mineral reactions, and tectonic settings of ore deposits that contain the mineral. [ABSTRACT FROM AUTHOR]

In the present work microstructural and chemical analysis of tin and slag that resulted from three smelting experiments reconstructing prehistoric conditions are presented. Cassiterite ores were collected from northwestern (NW) Iberian deposits and were smelted in a small open pit. Results show that the loss in tin can be very high, up to 80%, mainly as a result of volatilization of Sn species. The experiments show that using handmade leather bag bellows and clay tuyeres, temperatures can easily reach >1200°C. The tin produced was a very pure (Sn) solid solution, with the presence of dispersed inclusions or phases of various composition. These included FeSn and FeSn2 intermetallics and small metallic W inclusions. Slags could be grouped into three types based on their physical characteristics, and bulk chemical analysis could relate each type as being a product from the reaction of ore material or a product from the reaction with the crucible material. Generally, it was found that in spite of very low recovery rates, the tin produced by this simple technique would have been adequate for a domestic small-scale production. [ABSTRACT FROM AUTHOR]

To investigate the potential of tourmaline as a geochemical monitor, a comprehensive dataset on major, minor and trace element concentrations as well as Fe 3+ /ΣFe ratios of tourmaline is presented. The dataset includes samples from five plutonic complexes related to diverse magmatic to hydrothermal stages of the Cornubian Batholith (SW England). Tourmaline composition found in barren and cassiterite-bearing samples include all three primary tourmaline groups and tourmaline species with the general endmembers schorl, dravite, elbaite, uvite, feruvite, foitite and Mg-foitite. Based on textures and compositions, it is possible to distinguish not only between late-magmatic and hydrothermal tourmaline, but also between several formation stages. Hence, tourmaline monitors late-magmatic processes and the partitioning of elements during exsolution of an aqueous phase. For example, in hydrothermal tourmaline Sn is strongly enriched, while Ti, Cr, V and Sc are depleted compared to late-magmatic tourmaline of the same sample. Several tourmaline generations that precipitated from magmatic fluids can be distinguished with differing major and minor elements and REE patterns depending on the composition of the melt from which they were expelled from. Strongly zoned tourmaline allows for unraveling the hydrothermal history of a distinct location including ore precipitation. The precipitation of SnO 2 in the study area was probably caused by mixing between acidic, reduced, Sn-bearing magmatic fluids and oxidized meteoric fluids, which is in agreement with London and Manning (1995) and Williamson et al. (2000) . Hence, the ability of tourmaline composition to monitor changes in Sn concentration and redox conditions in hydrothermal fluids has potential as an exploration tool. [ABSTRACT FROM AUTHOR]

Gravity separation is typically used in the beneficiation of tin ores as the density difference between the valuable and associated gangue minerals is significant. In the present investigation, a cassiterite sample collected from the Uljin deposit in South Korea has been subjected to different gravity separators to evaluate the separation efficiency. The selection of gravity units has been made based on performance evaluation following heavy liquid separation and assessment of grade/recovery curves and Tromp curve methods. In addition, a gravity separation index (GSI) has been proposed that is simpler than other methods for assessing the performance of gravity separators. [ABSTRACT FROM AUTHOR]

The recently installed and unique PIXE (particle-induced X-ray emission) set-up at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) is mainly dedicated to applications for a detailed overview of elemental composition over large sample areas within a short time even at trace level. The so-called High-Speed-PIXE (HS-PIXE), a combination of a pnCCD-based pixel-detector with polycapillary X-ray optics, offers simultaneous imaging of sample areas up to 12 × 12 mm 2 with a lateral resolution better than 100 μm. Each of the 264 × 264 individual pixels detects X-ray photons in an energy range from 2 keV to 20 keV with an energy resolution of 152 eV (@Mn-K α ). A high precision sample manipulator offers the inspection of areas up to 250 × 250 mm 2 . During first experiments the determined resolution is (76 ± 23) μm using a sample of well-known sharp-edged chromium patterns. Trace element analysis has been performed using a geological sample, a tin ore, with an average Ta-concentration below 0.1 at.%. Fine-zoned structures became visible in the Ta-L α intensity map within only 45 min. The High-Speed-PIXE closes a gap in the analytical process flow chain especially for geoanalytical characterisations. It is a unique and fast detection system to identify areas of interest in comparably short time at large-area scale for further analysis. [ABSTRACT FROM AUTHOR]

In northern and central Portugal, there are different tin-bearing granites. Most of them are of S-type, others have mixed characteristics of I-type and S-type granites and a few are of I-type. Tin-tungsten deposits are commonly associated with Hercynian tin-bearing S-type granites. Some quartz veins with wolframite are associated with an I-type granite, which has a low Sn content. In suites of tin-bearing S-type granitic rocks, Sn content increases as a function of the degree of fractional crystallization. Greisenizations of two-mica S-type granites associated with tin-tungsten mineralizations are accompanied by an increase in SiO2, H2O+, Sn, W, Nb, Ta, Rb, Zn, and Pb and decrease in MgO, Na2O, V, Sc, Zr, and Sr. The granite associated with the Jales gold deposit is of S-type and strongly differentiated like the tin-bearing S-type granites, but it has a very low Sn content. During fractional crystallization, Si, Rb, Sn, Pb, Au, As, Sb, and S increase. During increasing degree of hydrothermal alteration of this granite at the gold-quartz vein walls, there are progressive increases in K2O, H2O+, Sn, Cs, Cu, Pb, Au, Sb, As, and S.

Cassiterite is the main ore mineral of Sn deposits, and may be used to date tin mineralization processes/processes. Both isotope dilution thermal ionization mass spectrometer (ID-TIMS) and laser ablation multi-collector inductively coupled plasma mass spectrometer (LA-MC-ICP-MS) have been applied to cassiterite U–Pb dating. Here we show that cassiterite U–Pb dating results using LA-ICP-MS are comparable to those using LA-MC-ICP-MS. Our results also show that Tera–Wasserburg U–Pb intercept age is far better than the previously used 206 Pb/ 207 Pb versus 238 U/ 207 Pb “isochron” age because the latter weighted data points with low proportions of common Pb more heavily, such that introducing larger errors. Moreover, 206 Pb i / 207 Pb changes with age and 238 U/ 207 Pb ratios, such that yields results younger than the real ages with larger errors. Samples with multiple common Pb sources are difficult to date. Nevertheless, multiple common Pb in cassiterite are often associated with fluid inclusions that may be identified and avoided. The precisions of cassiterite U–Pb ages are not as good as zircon ages, but they provide direct dating on the mineralization processes/processes. Therefore, coupled studies on zircon and cassiterite dating may provide constraints on the relation between magmatism ± hydrothermal activities and mineralization. [ABSTRACT FROM AUTHOR]

The article presents an outlook for the chemicals industry in Malaysia as of November 2015. Topics covered include the country's evolution from a commodities-based economy into a technology and engineering hub, the industrial-scale tin ore mining, and the Malaysian economy as the third biggest in Southeast Asia. Also mentioned are the natural rubber production and the introduction of synthetic rubber.

The South Caucasus was a major center of metal production in the Late Bronze and Early Iron Ages. Nowhere is this more clear than in the hills and mountains in the southeastern Black Sea region (ancient Colchis), where exceptionally large numbers of metal production sites have been found. Chemical and microscopic analysis of slagged technical ceramics at these sites illuminates several aspects of both raw copper and tin bronze alloy production. Copper ores were smelted in a complex multi-stage process designed to extract metal from sulfide ores. Technical ceramics served as containers for a range of different reactions, from the first phase of smelting, in which the copper sulfides were likely consolidated into a matte, though later stages of matte processing and metal copper production in smaller crucibles. In addition, a single crucible fragment, recovered from a late 2nd millennium BC slag heap, demonstrates that tin bronze was created by the direct addition of cassiterite tin ore, probably of alluvial origin, to metallic copper. The crucible's context, the use of cassiterite ore rather than tin metal, and a review of local geology suggests that the tin used in this crucible came from nearby, with the most likely source being the Vakijvari and Bzhuzhi gorges roughly 10–15 km away. While a single fragment does not speak to the regularity of this practice, at the very least it raises the possibility that the Colchian bronze industry was based on local rather than imported tin. [ABSTRACT FROM AUTHOR]

Granitic rocks obtained during field excursions of the famed mineralized regions of the Erzgebirge, Germany (mainly tin-bearing), and South China (mainly tungsten-bearing) have been geochemically analyzed and their results are compared with similar (mainly tungsten-bearing) granites in the island-arc setting of Southwest Japan. The studied granitoids all belong to the ilmenite-series. The collision-related Erzgebirge granitoids are rich in K2O and P2O5, have high A/CNK ratios (1.11-1.24, i.e. S type), but are also high in Ga/ Al ratio (i.e., having some A-type characteristics). In South China, the Xihuashan granites, in contrast, are very low in P2O5, and have A/CNK slightly above 1.0 (1.01-1.05), indicative of I type granites. The ( Sn-) W-related granites of southwest Japan have similarly low P2O5 and A/CNK ratios, indicative also of I-type. Both in the Xihuashan and southwest Japan, the tungsten-related granites have high whole-rock δ18O values implying involvement of W-rich crustal rocks. Sn and W contents of the unaltered granites are lowest in the island-arc setting where the related Sn- W deposits are smallest in size relative to the collision and continental margin settings of the Erzgebirge and South China. [ABSTRACT FROM AUTHOR]

China is rich in tin resources, and contains many types of tin deposits. Among the tin deposit types, the cassiterite-sulfide type, skarn type and quartz vein type occupy a large proportion of tin resources and reserves. From the aspect of exploitation and utilization, the most important types are cassiterite-sulfide type and quartz vein type. The cassiterite-sulfide type tin deposits are mainly located in Northern Guangxi and Eastern Yunnan, skarn type deposits are mainly distributed in the ore-concentration areas of South Hunan in Middle Nanling, and the quartz vein type tin deposits are mainly distributed in South China, such as Western Fujian, Middle Jiangxi, Northern Guangzhou and Southern Hunan. The most important metallogenic epoch for tin deposits is the Mesozoic era. The metallogenic geotectonic background is mainly continental environments after orogeny process, with strong tectonic changes, interlaced deep fracture and frequent magmatism. And the most distinctive feature is the well developed Mesozoic granites, which have a close relationship with tin mineralization. Based on the detailed study of the data from 873 tin deposits in China, this paper summarized the metallogenic regularity of tin deposits, classified 20 important metallogenic series of tin or tin-associated deposits, and inferred that the cassiterite-sulfide type, skarn type, quartz vein type and greisen type are the main prediction types of tin resources. Forty-four tin-mineralization belts were divided, among which, 19 belts are the most important. In addition, a series of maps about tin metallogenic belts and tin metallogenic regularity were compiled, aiming to provide theoretical basis for potential estimation and prediction of tin mineral resources. [ABSTRACT FROM AUTHOR]

Methylmercury (from fresh-water fish) and ethylmercury [from thimerosal-containing vaccines (TCVs)] are the most prevalent source of neurotoxic exposure during early life in families consuming fish and using these vaccines. But children living in Amazonian mining environments are exposed to additional toxic metals in waste materials. We studied mercury (Hg) exposure and neurodevelopment in 294 children (105 boys and 189 girls) from Bom Futuro (Rondonia, Brazil), the epicenter of a tin-ore open-pit mine. Hair-Hg (HHg) concentrations and total ethylmercury (from TCVs) were taken from infants and respective mothers during pregnancy. We used bivariate analysis to determine the effect of sex and linear mixed models to assess the association of prenatal and postnatal organic Hg exposures with children's Bayley Scales of Infant Development (BSID) as psychomotor developmental index and mental developmental index (MDI) at 6 and 24 months of age as well as milestones achievements (age of walking and age of talking). Significant differences between boys and girls were observed for both MDI score ( p = 0.0073) and MDI score ( p = 0.0288) at 6 months but not at 24 months. Regression analysis showed that only in boys was there a significant interaction between MDI score with family income ( β = 0.288, p = 0.018) and with birth weight ( β = −0.216, p = 0.036) at 6 months; at 24 months, however, only boys showed a significant association of both MDI score ( β = −0.222, p = 0.045) and MDI score ( β = −0.222, p = 0.045) with neonatal HHg. In boys, age of walking was associated with HHg ( β = 0.188, p = 0.019) and breastfeeding ( β = −0.282, p = 0.000), whereas for girls, age of walking was only associated with breastfeeding ( β = −0.275, p = 0.001). In this mining environment, with only a weak association for prenatal Hg exposure, there was a significant sex difference in neurodevelopment, with boys showing more sensitivity related to BSID delays. [ABSTRACT FROM AUTHOR]

This paper considers electrochemical tin deposition for producing contact elements in integrated circuit packaging. We examine the effect of organic additives to sulfate electrolytes on the growth of local vertical structures, with the aim of suppressing lateral growth of the deposit. [ABSTRACT FROM AUTHOR]

In this study we demonstrate the use of elemental precursors (Cu, Fe, Sn, S) to obtain stannite forms by a solid-state one-pot mechanochemical synthesis. In the processing route, we report the kinetics of the synthesis. For the characterization of the unique nanostructures, X-ray diffraction, specific surface area measurements and SQUID magnetometry methods were applied. CFTS polymorphs with the tetragonal body-centered structure with the average crystallite size 18-19 nm were obtained. The weak ferromagnetic properties of the quaternary nanocrystals after maximum milling time were also documented. [ABSTRACT FROM AUTHOR]

Tin is a rare metal that is essential for making bronze, the defining technology of the Bronze Age. The source(s) of tin for Aegean bronze is undetermined but several small Bronze Age tin mines have been documented in the circum-Aegean region. The discovery of Bronze Age archaeological sites in West Serbia near a tin placer deposit on the flanks of Mt. Cer led to an investigation of this site as a potential additional Bronze Age tin mine in the region. Geochemical prospecting of stream sediments flowing from Mt. Cer allowed for categorization of streams based on relative tin grade. Tin grade is highest in the Milinska River, a likely combination of a broad catchment area with multiple ore-bearing tributaries, and a topographic profile that favors the accumulation of placer deposits. A survey of cornfields along the southern pluton margin discovered archaeological sites spanning the Neolithic to the Iron Age. Unlike older and younger sites, those of the Bronze Age were found only along the Milinska and Cernica Rivers where placer tin grades are highest, but appear to be absent where tin is scarce or absent. This suggests that these sites were associated with the exploitation of the tin ore. [ABSTRACT FROM AUTHOR]

The Tengchong-Lianghe tin district in northwestern Yunnan, China, is an important tin mineralization area in the Sanjiang Tethyan Metallogenic Domain. There are three N-S trending granite belts in the Tengchong-Lianghe area, with emplacement ages ranging from Early Cretaceous to Late Cretaceous and Early Cenozoic. Tin mineralization is spatially associated with these granitic rocks. However, the petrogenetic link between the tin deposits and the host granites is not clear because of the lack of age data for the tin mineralization. We investigate the possibility of direct dating of cassiterite from three typical tin deposits in the Tengchong-Lianghe tin district, using laser ablation multicollector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS). In situ LA-MC-ICP-MS dating of seven cassiterite samples from the Lailishan (LLS-1 and LLS-2), Xiaolonghe (XLH, WDS, DSP, and HJS), and Tieyaoshan (TYS) tin deposits yielded well-defined Pb/Pb-U/Pb isochron ages. To assess the accuracy of the in situ U/Pb dating of cassiterite, Ar/Ar dating of coexisting muscovite (in samples LLS-1, DSP, and TYS) was also performed. The cassiterite in situ U/Pb ages (47.4 ± 2.0, 71.9 ± 2.3, and 119.3 ± 1.7 Ma, respectively) are in excellent agreement with the coexisting muscovite Ar/Ar ages (48.4 ± 0.3, 71.9 ± 1.4, and 122.4 ± 0.7 Ma, respectively). The U/Pb ages of cassiterite combined with the Ar/Ar ages of muscovite indicate that there are three tin mineralization events in this district: the Lailishan tin deposit at 47.4 ± 2.0 to 52 ± 2.7 Ma, the Xiaolonghe tin deposit at 71.6 ± 2.4 to 3.9 ± 2.0 Ma, and the Tieyaoshan tin deposit at 119.3 ± 1.7 to 122.5 ± 0.7 Ma. These ages are highly consistent with the zircon U/Pb ages of the host granites. It is su.ggested that the Cretaceous tin mineralization might have taken place in a subduction environment, while the Early Tertiary tin metallogenesis was in a postcollisional geodynamic setting. [ABSTRACT FROM AUTHOR]

The article focuses on the correlation between spatial location of surface ore deposits of the lower Amur River Region in China and Russia with the deep structures of the earth's crust. Topics discussed include three-dimensional gravity models that describes the rheological properties of tectonic media, types of ore layers in North Sikhote Alin in Russia that are characterized by gold, zeolites and polymetallic ores and fluid?magmatic sources of tin ore mineralization.

The structure and texture of the ores and ore-bearing metasomatic rocks at the Pravourmiisky tin-tungsten deposit are discussed. The zonal distribution of various genetic and morphological types of structure and texture has been revealed in vertical sections of the ore zone. The most diversity with a prevalence of cataclastic texture is characteristic of the middle (in section) ore zone segment, where the main economic greisen-type tin mineralization is hosted. Upsection, this mineralization gives way to the quartz-tourmaline Cu ore with widespread exsolution microtextures indicating high-temperature ore deposition. The structural and textural diversity of the ore is caused by the long-term geological history of the deposit under conditions of low-amplitude strike-slip and thrust faulting when compression was repeatedly followed by periods of relative quiescence or weak extension. [ABSTRACT FROM AUTHOR]

We provide a brief outline of the Middle Onon region and characterize the current status of the soils, vegetation and surface waters. We examine the environmental consequences of development of tin and gold deposits in the region, and suggest some avenues for recultivation of technogenically disturbed landscapes. [ABSTRACT FROM AUTHOR]

Abstract: Huashan, Guposhan and Qitianling are three similar and representative metaluminous A-type tin granites in the western Nanling Range, China. They all have a high oxidization state with magnetite as the dominant Fe–Ti oxide. This study presents an understanding of systematic mineralogy of Sn-bearing minerals (biotite, titanite, magnetite and cassiterite) in the three granites. Biotite has an annite composition and both electron-microprobe and LA-ICP-MS analyses indicate trace amounts of tin in biotite (approximately 100–20ppm). Chloritization of biotite is accompanied by formation of Sn-rich rutile and cassiterite. Titanite has a long history of crystallization from the early-magmatic stage through the late-magmatic stage to the hydrothermal stage. Owing to its solid-solution relationship with malayaite (CaSnSiO5), titanite always contains tin to various extents. Early-magmatic titanite contains about 0.5wt.% SnO2, while the late-magmatic titanite is markedly enriched in tin (on average 14.8 and 3.4 SnO2 in titanite from the Qitianling and Huashan granites, respectively). Magnetite grains typically display a trellis structure with ilmenite lamellae, where microinclusions of cassiterite (<1μm in size) are present. This is likely consistent with features of the “oxy-exsolution” process of Sn-bearing titanomagnetite precursor. Cassiterite may be observed as late-magmatic phase, but most commonly appears as an alteration product of other primary minerals. All tin-bearing minerals in the three granites record a complete process of tin mineralization in granite. The features of tin in primary biotite, titanite and magnetite reflect an initial enrichment during the early stage of magmatic crystallization of the Huashan, Guposhan and Qitianling granites. Association of interstitial Sn-titanite and cassiterite suggests further tin enrichment related to fractional crystallization of granitic magmas. Fluids and alteration of primary minerals play an important role in the leaching, concentration and transportation of Sn during hydrothermal processes, which favors vein-type Sn mineralization. [Copyright &y& Elsevier]

Abstract: Indium-bearing tin-polymetallic base metal deposits in Japan (Toyoha, Ashio and Akenobe), China (Dulong and Dachang), and Bolivia (Potosi, Huari Huari, Bolivar and Porco), were studied using femto-second Laser Ablation ICPMS (fsLA-ICPMS) and EPMA analyses for major and minor elements in sphalerite, paying special attention to In concentrations. Sphalerite is a principal mineral in these tin-polymetallic deposits and a broad range of In concentration is measured in the ores. There are distinct differences in mode of occurrence of the sphalerite and the distribution of In. The highest In concentration (up to 18wt.%) occur as a Zn–In mineral within black sphalerite zones in an oscillatory-zoned sphalerite from the Huari Huari deposits. Additionally, jamesonite from the Huari Huari deposit also contains anomalous In values, ranging from several hundreds to thousands μg/g. Sphalerite from the Toyoha and the other Bolivian deposits are characterized by oscillatory and chemical zoning, whereas those from Akenobe and the Chinese deposits are represented by homogeneous distribution of In. The 1000In/Zn values of sphalerite are in good agreement with those of the ore grade for each of the selected tin polymetallic deposits indicating that sphalerite is the principal host of In. The In-bearing sphalerite principally involves the combined coupled substitutions (2Zn2+)↔(Cu+, In3+), (3Zn2+)↔(Cu+, Ag+, Sn4+) and (3Zn2+)↔(2Cu+, Sn4+). The first of these is apparent in sphalerite from Huari Huari and Bolivar, whereas the second is prominent in sphalerite from Toyoha, Ashio, Potosi, Porco and Dachang. Akenobe and Dulong sphalerite features the dominant coupled substitution of (2Zn2+)↔(Cu+ or Ag+, In3+), owing to their poor Sn content. Occasionally, sub-micron inclusions of minerals such as stannite and Pb–Sb-bearing sulfides can occur in sphalerite, contributing to high Cu–Sn and high-Ag contents, respectively. The observed correlations of each element in the In–Cu–Ag–Sn-bearing sphalerite can be proposed as a fundamental reason for the indium enrichment related to sulfur-rich oxidized magmatism. In addition, the Ag content in sphalerite is considered a possible indicator of formation depth, which ranges from plutonic to subvolcanic environments. [Copyright &y& Elsevier]

The Mesoproterozoic Kibara belt (KIB) and the Karagwe-Ankole Belt (KAB) in Central Africa are characterized by the presence of numerous rare metal mineralized Sn-(Nb-Ta) pegmatites and Sn-W mineralised quartz veins that are related to a S-type granite generation formed at 986 ± 10 Ma. Cassiterite concentrates have been studied by different petrographic and mineralogical techniques. The concentrates have been collected from the rock and mineral collection of the Royal Museum for Central Africa (RMCA) and originate from historical exploitations of eluvial and alluvial cassiterite deposits. No quantitative study of the concentrates has been envisaged since no information is available about the history of the samples prior to sampling. Microscopic investigation revealed the presence of cassiterite crystals with metallic and non-metallic luster, of which the latter show growth zoning. The color from the cassiterite crystals can vary from transparent colorless to black non-transparent. The variation in color in a single grain can be as varied as the color variation between grains for an entire concentrate. The mineralogical composition of the cassiterite concentrates contains minerals that are typical gangue and accessory minerals in the primary mineralization and that were liberated dufing weathering. In addition, minerals can be round that result from the weathering from the metasedimentary and doleritic host-rocks of the primary mineralization. Except the occasional presence of a certain mineral or a special color for a certain cassiterite, no systematic variation can be observed between the concentrates from the different locations. Often, the mineral and color variation in one concentrate can be as large as for concentrates round from different locations. [ABSTRACT FROM AUTHOR]

The degree of soil contamination in the impact zone of the Solnechnyi Tin Ore Processing Plant in the Solnechnyi district of the Khabarovsk region was evaluated. It was shown that the air contamination by the waste products of the ore-processing plant is extremely high with respect to the concentrations of toxic dust and heavy metals. The maximum concentrations of these contaminants exceed the background values by 16-80 times. The bulk contents of Pb, Zn, Cu, As, and Hg in the upper soil horizons within the impact zone exceeded the maximum permissible concentrations and the background values by 2-90 times. Abnormally high concentrations of Zn, As, and Pb were observed not only in the surface 10-cm-thick soil layer but also in the underlying (10-20 cm) horizon. The soil contamination transformed the geochemical sequence of heavy metals typical of the background soils (Zn > Pb > As > Cu > Hg) into a new sequence (As > Pb > Cu > Zn > Hg). The statistical data proved that the intensity of the migration of the heavy metals in the soils decreases with a rise in the soil humus content and a drop in the soil acidity. This should be taken into account in the elaboration of soil-protective measures in the investigated region. [ABSTRACT FROM AUTHOR]

Vein-type tin mineralization in the Dadoushan deposit, Laochang ore field, Gejiu district, SW China, is predominantly hosted in Triassic carbonate rocks (Gejiu Formation) over cupolas of the unexposed Laochang equigranular granite intrusion. The most common vein mineral is tourmaline, accompanied by skarn minerals (garnet, diopside, epidote, phlogopite) and beryl. The main ore mineral is cassiterite, accompanied by minor chalcopyrite, pyrrhotite, and pyrite, as well as scheelite. The tin ore grade varies with depth, with the highest grades (~1.2 % Sn) prevalent in the lower part of the vein zone. Muscovite Ar-Ar dating yielded a plateau age of 82.7 ± 0.7 Ma which defines the age of the vein-type mineralization. Measured sulfur isotope compositions ( δS = −4.1 to 3.9 ‰) of the sulfides (arsenopyrite, chalcopyrite, pyrite, and pyrrhotite) indicate that the sulfur in veins is mainly derived from a magmatic source. The sulfur isotope values of the ores are consistent with those from the underlying granite (Laochang equigranular granite, −3.7 to 0.1 ‰) but are different from the carbonate wall rocks of the Gejiu Formation (7.1 to 11.1 ‰). The calculated and measured oxygen and hydrogen isotope compositions of the ore-forming fluids ( δO = −2.4 to 5.5 ‰, δD = −86 to −77 ‰) suggest an initially magmatic fluid which gradually evolved towards meteoric water during tin mineralization. [ABSTRACT FROM AUTHOR]

Results from many years of investigations of the ecological state of environmental sites in Primorie and Priamurie are discussed. It is found that processing wastes of tin ore feed-stock have a negative influence on the ecosphere as a whole. It is found that the levels of ions of ammonium, arsenic, copper and other heavy metals in snow cover exceed maximum permissible concentration (MPC). The study revealed a significant accumulation of total and mobile forms of elements in soils and vegetation. Some recommendations and suggestions are made in order to cope with the ecological problems. [ABSTRACT FROM AUTHOR]

The effect of wastes from tin ore processing on environmental objects is evaluated. Measures aimed at providing environmental and social safety are proposed. [ABSTRACT FROM AUTHOR]

The author's database, which presently includes data from more than 18500 publications on fluid and melt inclusions in minerals and is continuing to be appended, was used to generalize results on physicochemical parameters of the formation of hydrothermal deposits and occurrences of tin and tungsten. The database includes data on 320 tin and tin-tungsten deposits and occurrences and 253 tungsten and tungstentin deposits around the world. For most typical minerals of these deposits (quartz, cassiterite, tungsten, scheelite, topaz, beryl, tourmaline, fluorite, and calcite), histograms of homogenization temperatures of fluid inclusions were plotted. Most of 463 determinations made for cassiterite are in the range of 300-500°C with maximum at 300-400°C, while those for wolframite and scheelite (453 determinations) fall in the range of 200-400°C with maximum at 200-300°C. Representative material on pressures of hydrothermal fluids included 330 determinations for tin and 430 determinations for tungsten objects. It was found that premineral, ore, and postmineral stages spanned a wide pressure range from 70-110 bar to 6000-6400 bar. High pressures of the premineral stages at these deposits are caused by their genetic relation with felsic magmatism. Around 50% of pressure determinations lie in the range of 500-1500 bar. The wide variations in total salinity and temperatures (from 0.1 to 80 wt % NaCl equiv and 20-800°C) were obtained for mineral-forming fluids at the tin (1800 determinations) and tungsten (2070 determinations) objects. Most of all determinations define a salinity less than 10 wt % NaCl equiv. (∼60%) and temperature range of 200-400°C (∼70%). The average composition of volatile components of fluids determined by different methods is reported. Data on gas composition of the fluids determined by Raman spectroscopy are examined. Based on 180 determinations, the fluids from tin objects have the following composition (in mol %): 41.2 CO, 39.5 CH, 19.15 N, and 0.15 HS. The volatile components of tungsten deposits (190 determinations) are represented by 56.1 CO, 30.7 CH, 13.2 N, and 0.01 HS. Thus, the inclusions of tungsten deposits are characterized by higher CO content and lower (but sufficiently high) contents of CH and N. The concentrations of tin and tungsten in magmatic melts and mineral-forming fluids were estimated from analysis of individual inclusions. The geometric mean Sn contents are 87 ppm (+ 610 ppm/−76 ppm) in the melts (569 determinations) and 132 ppm (+ 630 ppm/−109 ppm) in the fluids (253 determinations). The geometric mean W values are 6.8 ppm (+ 81/−6.2 ppm) in the magmatic melts (430 determinations) and 30 ppm (+ 144 ppm/−25 ppm) in the mineral-forming fluids (391 determinations). [ABSTRACT FROM AUTHOR]

The solubility of SnO(cassiterite) was studied at 23±2 °C as a function of time (7 to 49 days) and pH (0 to 14.5). Steady state concentrations were reached in <7 days. The data were interpreted using the SIT model. The data show that SnO(cassiterite) is the stable phase at pH values of < ∼11.7. These extensive data provided a log K value of −64.39±0.30 for the reaction (SnO(cassiterite) +2HO⇄Sn+4OH) and values of 1.86±0.30, ≤−0.62, −9.20±0.34, and −20.28±0.34 for the reaction ( $\mathrm{Sn}^{4+} + n\mathrm{H}_{2}\mathrm{O} \rightleftarrows \mathrm{Sn}(\mathrm{OH})_{n}^{4 - n} + n\mathrm{H}^{+}$) with values of ' n' equal to 1, 4, 5, and 6 respectively. These thermodynamic hydrolysis constants were used to reinterpret the extensive literature data for SnO(am) solubility, which provided a log K value of −61.80±0.29 for the reaction (SnO(am)+2HO⇄Sn+4OH). SnO(cassiterite) is unstable under highly alkaline conditions (NaOH concentrations >0.003 mol⋅dm) and transforms to a double salt of SnO and NaOH. Although additional well-focused studies will be required for confirmation, the experimental data in the highly alkaline region (0.003 to 3.5 mol⋅dm NaOH) can be well described with log K of −5.29±0.35 for the reaction NaSn(OH)(s)⇄NaSn(OH)(aq). [ABSTRACT FROM AUTHOR]

The present work is aimed to compare the physical properties of $\mbox{Sn}_{1-x} \mbox{Fe}_x \mbox{O}_{2-\delta } $ ( x = 0, and 0.05) nanopowders obtained by sol–gel method, mechanochemical alloying, and mechanochemical alloying followed by thermal treatment. The X-ray diffraction of $\mbox{Sn}_{1-x} \mbox{Fe}_x \mbox{O}_{2-\delta } $ samples prepared by sol–gel showed peaks due to the cassiterite phase of SnO2 and thier Mössbauer spectra showed ferromagnetic and paramagnetic signals. The samples obtained by the milling process of SnO2 mixed with $\upalpha $-Fe showed Bragg peaks due to SnO2 (rutile) with a line broadening caused by the reduction of grain sizes and the presence of microstrains. Mössbauer spectra for these samples revealed the presence of Fe3 + as well as unreacted $\upalpha $-Fe. In the case of mechanochemical alloying with thermal treatment, the incorporation of Fe3 + in the SnO2 structure with the presence of impurities was observed. [ABSTRACT FROM AUTHOR]

Abstract: Two granitoid complexes in the eastern Kyrgyz Tien Shan, situated north and south of the Southern Tien Shan Suture, were studied. The suture formed as a result of the closure of the Turkestan Ocean and collision of the Tarim microcontinent in the south with the Middle Tien Shan in the north. The timing of collision is still disputed. The deformed calc-alkaline Terektinsky complex, situated immediately north of the suture, represents one of the largest shear-zone related intrusions in the Tien Shan (130×5–15 km in size). Small stocks of evolved A-type granites of the Inylchek complex, hosting economic tin mineralization, were emplaced immediately south of the suture opposite the Terektinsky complex. Two samples from the Terektinsky complex and 3 samples from three A-type stocks were collected for U–Pb zircon SHRIMP-II geochronology. The ages at 2σ level obtained for the Terektinsky complex north of the suture (294+5 Ma and 291+5 Ma) and ages of the small granite bodies south of the suture (299+4 Ma, 295+4 Ma, 289+6 Ma; Tashkoro, Inylchek and Maida''adir intrusions, respectively) are nearly identical, within error limits. They show that the Southern Tien Shan Suture in the eastern Kyrgyz Tien Shan had already formed by ~295 Ma, and had evolved into a transcrustal mega-shear zone controlling emplacement of granitoids. Geochemical distinction between the two magmatic systems is based on 10 original bulk and trace analyses of rocks from this study and on a large dataset extracted from previously published research and unpublished reports. Geochemically, the rocks of the Terektinsky complex comprise calc-alkaline (high potassium I-type) series while the granites of the Inylchek complex are typical A-type granites with an elevated alumina saturation index and higher boron contents compared to a “standard” A-type rapakivi granite. Contrasting metallogenic features of the two granitoid complexes south and north of the Southern Tien Shan Suture are defined by their sources: a fertile fore-arc complex, and/or passive margin sediments of Tarim to the south, and barren metamorphic Precambrian basement of the Middle Tien Shan to the north. [Copyright &y& Elsevier]

Abstract: The solubility of cassiterite was investigated experimentally in liquid-undersaturated HCl-bearing water vapour at temperatures of 300 to 350 °C and pressures up to 180 bar. Concentrations of tin varied between 0.1 and 32 ppb, depending on experimental conditions, and reached a maximum at 320 °C. These concentrations are at least four orders of magnitude higher than those reported for the water-free system. Positive correlation of the concentrations of tin with f H2O and f HCl indicate that cassiterite solubility is enhanced by solute–solvent interaction, and that this involves the formation of hydrated gaseous species of tin chloride having a tin–chlorine ratio of 1:2, and statistical hydration numbers of 2.9, 2.7, and 2.5 at 300, 320, and 350 °C, respectively. We therefore propose that the solubility of cassiterite in HCl-bearing water vapour is explained by the reaction: Calculations based on this reaction and data for the solubility of tin in aqueous liquids indicate that, under all conditions, tin partitions preferentially into the latter phase. However, in high salinity, two-phase aqueous systems, where vapour pressures can be considerably higher than those in our experiments and chlorinity is not controlled by f HCl, but by NaCl content, tin solubility in the vapour phase may be appreciable. [Copyright &y& Elsevier]

Single phase samples of the compounds Cu2CoSi(Ge,Sn)S4 and Cu2CoGe(Sn)Se4 were prepared. The crystal structures of these compounds were investigated using X-ray powder diffraction. The compounds Cu2CoSi(Ge,Sn)S4 and Cu2CoSnSe4 crystallize in the stannite structure (space group I&4macr;2m) with the lattice parameters: a=0.52644(1) nm, c=1.03160(5) nm (Cu2CoSiS4), a=0.52957(1) nm, c=1.04709(5) nm (Cu2CoGeS4), a=0.53956(8) nm, c=1.0789(3) nm (Cu2CoSnS4) and a=0.56676(2) nm, c=1.13146(9) nm (Cu2CoSnSe4). The atomic parameters were refined in the isotropic approximation (RI=0.0770, 0.0736, 0.0638; and 0.0541 for Cu2CoSiS4, Cu2CoGeS4, Cu2CoSnS4 and Cu2CoSnSe4, respectively). The Cu2CoGeSe4 compound crystallizes in an orthorhombic unit cell (space group F222) with the lattice parameters a=0.55858(6) nm, b=0.55560(6) nm, c=0.54935(5) nm (RI=0.0429). [Copyright &y& Elsevier]

This article presents results of the studies on development of viable process route for quantitative recovery of tungsten and tin values occurring together in the form of a multimineral concentrate of wolframite, scheelite, and cassiterite. The investigations were carried out using a tin–tungsten multimineral ore from Kyrgyzstan (Central Asia). Tungsten minerals in this ore occur both as distinct liberated mineral phases and as composites, viz. ultrafine dissemination of wolframite in scheelite and vice versa. Cassiterite also has similar characteristics, albeit to a lesser extent, with few grains containing ex-solution intergrowth of columbite/tantalite and very fine dissemination of tungsten minerals in its lattice. The complex nature of occurrence of both tungsten and tin minerals necessitated an integrated process comprising physical beneficiation and chemical extraction. The process route that was developed gave a tungsten and tin recovery of about 80 and 90%, respectively, on treating a primary gravity preconcentrate analyzing 16.5% WO3 and 25.7% Sn. [ABSTRACT FROM AUTHOR]

Adsorption and electrokinetic characteristics of tin dioxide (cassiterite) are studied as a function of pH in aqueous NaCl and KCl solutions. The dissociation constants of surface groups, formation constants of ion pairs, and the adsorption potentials of ions are calculated in terms of the 2-pK model; capacities and potentials of the electrical double layer are determined; the dissociation degree of surface groups in the point of zero charge and in the isoelectric point are also estimated. It is shown that the 2-pK model in combination with the Graham model can be applied in the studied systems for describing the experimental results. [ABSTRACT FROM AUTHOR]

Oxygen diffusion into metallic In/Sn films and crystallite growth of thin indium tin oxide (ITO) films were investigated by in situ high temperature grazing incidence X-ray diffractometry (HT-GIXRD) at temperatures ranging from 100 to 300 °C. The investigated films were deposited by dc magnetron sputtering from a metallic target at different oxygen flows and bias voltages. The deposition process influences not only the film properties but also the film reactions during the post-deposition annealing process.The ITO formation is determined by two processes: the diffusion of oxygen into the metallic grains and a fast crystallization process. Kinetic parameters for both processes were derived. A model was developed which allows the determination of the diffusion coefficient D from the time dependence of the integral intensity of the ITO X-ray reflection. Diffusion coefficients as well as the activation energies are influenced by the bias voltage but not by the oxygen flow.According to the Johnson–Mehl–Avrami theory, the crystallization can be described as a two-dimensional process. [Copyright &y& Elsevier]