Geochemistry Of Tin Research Articles

Geochemistry of tin (Sn) in Chinese coals.

Based on 1625 data collected from the published literature, the geochemistry of tin (Sn) in Chinese coals, including the abundance, distribution, modes of occurrence, genetic types and combustion behavior, was discussed to make a better understanding. Our statistic showed the average Sn of Chinese coal was 3.38mg/kg, almost two times higher than the world. Among all the samples collected, Guangxi coals occupied an extremely high Sn enrichment (10.46mg/kg), making sharp contrast to Xinjiang coals (0.49mg/kg). Two modes of occurrence of Sn in Chinese coals were found, including sulfide-bounded Sn and clay-bounded Sn. In some coalfields, such as Liupanshui, Huayingshan and Haerwusu, a response between REEs distribution and Sn content was found which may caused by the transportation of Sn including clay minerals between coal seams. According to the responses reflecting on REEs patterns of each coalfield, several genetic types of Sn in coalfields were discussed. The enrichment of Sn in Guangxi coals probably caused by Sn-rich source rocks and multiple-stage hydrothermal fluids. The enriched Sn in western Guizhou coals was probably caused by volcanic ashes and sulfide-fixing mechanism. The depletion of Sn in Shengli coalfield, Inner Mongolia, may attribute to hardly terrigenous input and fluids erosion. As a relative easily volatilized element, the Sn-containing combustion by-products tended to be absorbed on the fine particles of fly ash. In 2012, the emission flux of Sn by Chinese coal combustion was estimated to be 0.90×10(9)g.

Mineralogy and geochemistry of tin- and germanium-bearing copper ore, Barrigão re-mobilized vein deposit, Iberian Pyrite Belt, Portugal

The Barrigão re-mobilized copper vein deposit, Iberian Pyrite Belt, southern Portugal, is located about 60 km south of Beja and 10 km southeast of the Neves Corvo ore deposit, in Alentejo Province. The deposit is structurally associated with a NE–SW striking fault zone inferred to have developed during late Variscan deformation. The copper ore itself is a breccia-type ore, characterized by up to four ore-forming stages, with the late stages showing evidence of fluid-driven element re-mobilization. The ore is dominated by chalcopyrite + tennantite-tetrahedrite, with minor arsenopyrite, pyrite, and löllingite. The supergene paragenesis is composed mainly of bornite, covellite, and digenite. Whole-rock analyses show anomalous tin and germanium contents, with averages of 320 and 61 ppm, respectively. Electron microprobe analysis of Barrigão ores revealed the germanium and tin to be restricted to chalcopyrite, which underwent late-stage hydrothermal fluid overprint along distinct vein-like zones. The measured zonal enrichment of tin and germanium is related to limited element re-mobilization associated with mineral replacement, which resulted in distinctive mineral disequilibrium. Fluid-driven element zoning affected chalcopyrite and tennantite coevally. The average contents of germanium and tin in chalcopyrite are of 0.19 and 0.55 wt.%, respectively, as confirmed through additional micro-proton-induced X-ray emission (micro-PIXE) analysis. The distribution of tin and germanium in chalcopyrite correlates strongly with iron. Tin and germanium covary. Minute sub-microscopic inclusions of an unknown Cu–Sn–Ge sulphide phase have been detected in chalcopyrite and in small vugs therein. These inclusions hint at a stanniferous sulphide as the most possible host for tin and germanium in chalcopyrite, although the idea of limited incorporation of these two elements through element substitution cannot be completely excluded.

Geochemistry of tin in rivers and estuaries

On the basis of measurements from a large number of rivers from pristine and polluted regions, we estimate the riverine fluxes of tin to the oceans to be 0.76 × 10 6 mol yr −1 for the dissolved fraction and 300–600 × 10 6 mol yr −1 for the paniculate fraction. The paniculate flux agrees with the flux calculated from denudation rates. Estuaries were found not to have a large effect upon the transport of tin to the oceans. Evidence for the remobilization of tin was found in an estuary that is highly polluted with tin from mining and smelting activities. Monobutyltin was found to be present in polluted estuaries and is presumed to be a degradation product of tributyltin additives to antifouling paint.

Geochemistry of tin, tungsten and molybdenum in Swedish proterozoic granitoids: Their potential use in regional mineral exploration

Abstract The primary aim of this broad regional study is to statistically determine the Li-Sn-W-Mo-bearing potential of various granitoids using geochemical criteria. Computer based, univariate and multivariate statistical methods are applied to major- and trace-element data from about 660 granitic rock samples and over 800 major element analyses, selected from the Swedish geological literature. The granitoids are subdivided following earlier geotectonic chronologic and newer geochemical-statistical principles. Most granite types occurring in known Sn-W mineralized areas, except the granites around the W deposit of Baggetorp, were identified as potentially W-Sn-bearing. That is, they show significantly high mean and variance values for W and/or Sn as well as promising values of the probability parameters for these elements, compared to corresponding statistics for a calculated Swedish average granitoid (SAG). Evidence of very high total variability of Li, Sn and W within the individual granite types suggests the need for further tests, to control the variability errors due to sampling and preparation and errors of chemical analysis. These sources of error may obscure natural elemental heterogeneity of the granite type that is of interest in geochemical prospecting. Interpretations of Sn, W and Li frequency distribution patterns, petrochemical trends and multivariate similarity tests suggest that the primary chemistry of the granitoids is overprinted by (a) postmagmatic processes of broad regional nature, which have similarly affected the individual granite types, and (b) a wide variety of secondary alterations of local character. These conclusions imply that potential Sn and W deposits may be sought within all Swedish Proterozoic granitoids and their within all Swedish Proterozoic granitoids and their immediate sorroundings, where susch processes have redistributed and concentrated these where such processes have redistributed and concentrated these elements. However, the granites which are highly differentiated, Sn-W-Li-U-Th-F-enriched, and strongly and strongly magnetic are particularly promising target areas for further, extensive rock-geochemical prospecting and other exploration surveys. rock-geochemical prospecting and other exploration surveys.

Tin ore potential of the South Island, New Zealand

Abstract The distribution of cassiterite and its obvious assoCIatIOn with granitic rocks in the South Island suggests the possibility of the existence of commercial concentrations of tin ore. The formation of tin ore deposits in general is briefly described, in particular to show how knowledge of the geochemistry of tin can aid exploration. The known occurrence and distribution of cassiterite in the South Island are reviewed, exploration methods are discussed, and suggestions are made for a comprehensive investigation of the tin ore potential.

The geochemistry of tin

In order to obtain more reliable and comprehensive geochemical figures about tin. neutron activation analyses were undertaken for widely selected materials of geochemical interests. Analyses are given for 35 silicic (av. 3.6 ppm Sn). 19 intermediate (av. 1.5 ppm). 3 mafic (av. 0.9 ppm) and 4 ultramafic rocks (av. 0.35 ppm). Data for 10 red clays (av. 4.9 ppm), 3 globigerina oozes (av. 1.5 ppm) and 4 volcanic muds (av. 1.4 ppm), all of them collected from the Pacific Ocean, and 3 red clays of the Japan Sea (av. 4.1 ppm) are also given. Our results on the abundance values for tin in various types of igneous rocks, as well as of red clays. confirm the figures given by Onishi and Sandell (1957). Contrary to the previous information about the geochemistry of tin, we found that tin should be thought of as being distributed as a “trace element” rather evenly throughout the erustal rocks. Pelagic sediments do not show any marked enrichment of tin compared with igneous rocks. The striking similarity in the concentrations of tin in the pelagic argillaceous sediments, terrestrial clays and igneous rocks suggests a mainly terrigenous origin for the deep-sea sediments rather than one involving the submarine weathering of volcanics and pyroclastics. Sea water samples of the Pacific Ocean give the value of 0–81 /tg Sn/1. as an average. The enrichment factor for tin for marine animals is estimated to be about ~2400 to a good order of magnitude.