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Arsenic Poisoning through Ages
Published in M. Manzurul Hassan, Arsenic in Groundwater, 2018
Arsenic is a metalloid that exhibits both metallic and nonmetallic chemical and physical properties. Arsenic does not often form in its elemental state, but more commonly it is found either in primary arsenic-bearing minerals or adsorbed on to various mineral phases such as iron and aluminum oxides, clays, and iron sulfides. Worldwide, most arsenic is produced as a by-product of copper and lead smelting. Native arsenic is found in the environment in small quantities, usually in ores containing gold, silver, cobalt, nickel, and antimony. The most common arsenic-bearing minerals are arsenopyrite (FeAsS), orpiment (As2S3), realgar (As2S2), scorodite (FeAsO4 ⋅ 2H2O), löllingite (FeAs2), and tennantite ([Cu,Fe]12As4S13), of which arsenopyrite is the most common (Table 1.2). Other arsenic-bearing minerals include enargite (Cu3AsS4), cobaltite (CoAsS), niccolite (NiAs), arsenolite (As4O6), claudetite (As2O3), and erythrite (Co3(AsO4)2 ⋅ 8H2O). However, these mostly occur as accessory minerals in ore deposits (Grund et al., 2005; Mason and Berry, 1978; Ravenscroft et al., 2009: 26) and are not known to be responsible for any cases of arsenic pollution.
The Fate of the Arsenic Species in the Pressure Oxidation of Refractory Gold Ores: Practical and Modelling Aspects
Published in Mineral Processing and Extractive Metallurgy Review, 2023
Wei Sung Ng, Yanhua Liu, Qiankun Wang, Miao Chen
Arsenic oxides in nature commonly take the form of arsenic trioxide as arsenolite (As4O6) or claudetite (As2O3) and occur primarily through the weathering and oxidation of realgar and orpiment (Đorđević et al. 2019). Other forms of arsenic oxides, such as arsenic dioxide (As2O4) and pentoxide (As2O5), rarely occur readily in nature. Due to the conditions of its formation, it is rare for arsenic oxides to be present in gold-bearing sulfide deposits in more than trace quantities.