METHOD FOR OBTAINING A NON-STOICHIOMETRIC ARSENIC POLYSULFIDE COMPOUND INSOLUBLE IN GROUNDWATER Russian patent published in 2023 - IPC C01G28/00 C01B17/20 B09B3/00 

FIELD: mining industry.

SUBSTANCE: invention relates to the mining, metallurgical and chemical industries, as well as to environmental protection and can be used as part of a hardening filling mixture to fill exhausted spaces in mines that are not flooded by groundwater. Non-stoichiometric arsenic polysulfide compounds insoluble in groundwater are obtained by mixing and sintering sulfide-arsenic cake with powdered elemental sulfur, the consumption of which is 15-20, wt. %, of the cake. The cake is pre-dried to a residual humidity of no more than 1.5%. Sintering is carried out at a temperature of 330-340°C for 2.0-2.5 hours. The resulting vitreous product consists of approximately 99% non-stoichiometric arsenic polysulfide, similar in composition to As₂S₅.

EFFECT: invention makes it possible to neutralize and dispose of dangerous and toxic sulfide-arsenic cakes, as well as to exclude their ingress into the environment, including groundwater.

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