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Abstract  

The changes in specific surface area and structure disorder of mechanically activated arsenopyrite were investigated. The rate of nonoxidative decomposition of mechanically activated arsenopyrite was increased almost 10-times when compared with nonoxidative decomposition of a non-activated sample. An empirical linear relationship was found (r=0.996) between the rate constant of decomposition and the ratio of specific surface to transmission of the absorption band of arsenopyrite at
\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $$\bar \nu = 370 cm^{ - 1}$$ \end{document}
. This relationship enables us to arrange the reaction 4FeAsS→4FeS+As4 among structure-sensitive reactions.
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-yellow color and distributed at all size classes. BSE image and EDX data of the studied galena were presented at Fig. 9a . Fig. 9. BSE images and EDX spectra of sulfide minerals; (A) Pyrite, (B) Arsenopyrite, (C) Galena, and (D) Molybdenite Arsenopyrite is an

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Abstract  

A method has been worked out of multi-elemental instrumental neutron-activation analysis INAA of small weights some mg of monomineral fractions of sulfide minerals pyrites, galenites, chalcopyrites, arsenopyrites, bornites, chalcosines and quartzes. The samples were irradiated in a nuclear reactor under a flux of 1.3·1013 n·cm−2·s−1. For measuring the gamma radiation of the exposed samples Ge(Li) gamma-spectrometers with semiconductor detectors were used. Determined in sulfide monofractions were the elements: Co, Sc, Ag, Se, Sb, Cr, Fe, Zr; rare-earth elements: Ce, Sm, Eu and others at content levels of 10−1−10−4%. In quartzes they were: Mn, Na, Sb, Cr, Sc, Fe, Co at content levels of 10−5−10−7% and Au to n×10−9%. A special method has been worked out for the determination of In in sulfides with the irradiation of samples in a cadmium screen. An example is cited of using the method for studying some peculiar features of the genetics of copper pyrite deposits. The data on the distribution of admixture elements in sulfide monofractions produced in this work made it possible to conclude that the oreformation in the deposits has a stage-by-stage character.

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Abstract  

Gold has been mined on a large scale at Yellowknife located in the sub-arctic North West Territories of Canada since 1938. The gold is associated with arsenopyrite ores, with necessitates the oxidation of the arsenic and sulphur by roasting at two Yellowknife smelters. Other metals are also present in the ore, notably antimony. As2O3 and SO2 are emitted into the atmosphere. Large quantities of arsenic were liberated in the past and despite improvements in emission control, significant emission still occur. In order to assess the amount and extent of arsenic contamination in the local environment and the potential exposures and sources to man, soil samples and samples of the native vegetation were collected in and around the town of Yellowknife and the two smelters. Arsenic and antimony analyses were done by instrumental neutron activation analysis using the SLOWPOKE facility at University of toronto. Air-dried plant samples were bombarded at a neutron flux of 1·1012n cm2s and soil samples at 2.5·1011n cm2s for 6 minute periods. The122Sb and76As-ray emissions at 559 keV were analysed after decay periods of 24–48 hours and compared with standard solutions and NBS standards. Zinc, copper, lead and cadmium analyses were done by atomic absorption spectrophotometry. Arsenic was found to be accumulated in the soils in the vicinity of the two smelters to levels of several thousand ppm. Concentrations greater than 500 ppm occurred in the soil of Yellowknife townsite, and greater than 50 ppm occurred at all sites sampled within 15 km of the town. Antimony levels were about 10% of arsenic and were highly correlated with arsenic. Zinc occurred to 500 ppm around the smelters. Compared with background levels, the foliage of several native species showed substantial arsenic accumulation, up to several hundred ppm in birch. Only 5–25% of this arsenic could be removed by careful washing. Evidence suggests the arsenic is taken up from the soil creating an ongoing arsenic contamination problem. Soil arsenic levels are also sufficiently high to inhibit root growth in soils over a very extensive area.

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-sulfide, arsenopyrite mine-waste using micro X-ray diffraction . Canadian Mineralogist , 43 : 1243 – 1254 . 10.2113/gscanmin.43.4.1243 Hedenquist , J.W. , Arribas , A.R. , and Gonzales-Urien , E. ( 2000 ) Exploration for gold deposits . In: Hagemann , S

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, and indium. Primary mineralization includes pyrite, chalcopyrite, sphalerite, and cassiterite; secondary minerals are arsenopyrite, galena, gold, silver, and tennantite [Sistema de Informação de Ocorrências e Recursos Minerais Portugueses (SIORMINP

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