The dissolution of stibnite(Sb2S3)is an important source of antimony in the aqueous environment,and the toxicity,mobility and bioavailability of dissolved antimony in water are closely related to its morphology,but the current understanding of the morphological distribution of antimony in the dissolution products of stibnite is not consistent,and the understanding of the particular form of antimony,thioantimonate,is particularly controversial.In this context,it systematically investigated the dissolution process of stibnite and its effect on the formation of thioantimonate under different aqueous conditions,to provide a basis for the accurate evaluation of the environmental effects of stibnite dissolution.The results show that the dissolution of stibnite under acidic-weak alkaline conditions does not lead to the formation of thioantimonate,while under alkaline conditions trithioantimonate and tetrathioantimonate can be formed;the dissolution of stibnite is unlikely to lead to the formation of poly-thioantimonate when the initial total antimony content in the reaction system is comparable to that in natural water.In addition,the coexistence of different types of reduced sulfur or moderate amounts of orpiment and an increase in the ionic strength of the water can promote the formation of thioantimonate,which is inhibited by excess orpiment.The S(-Ⅱ)/Sb molar ratio in water is an important factor in controlling the formation of thioantimonate;the S(-Ⅱ)/Sb molar ratio is a key indicator to be considered when examining the environmental impact of stibnite leaching in natural water environments and the potential for thioantimonate formation during leaching.
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