Research features of opening of refractory arsenopyrite concentrates by using low-temperature roasting

Abstract

The article describes an alternative pre-treatment method of refractory arsenopyrite concentrates using low temperature roasting. The process consists of carrying out oxidative roasting in the temperature range of 200-400 C - relatively low for traditional process. The calculation results of the equilibrium composition of roasting products are presented on the example of a flotation gold-bearing concentrate of the Uderey's deposit in the HSC Chemistry 6 program. The main concentrate minerals containing gold arepyrite (FeS2) and arsenopyrite (FeAsS). In addition, the concentrate of the Uderey's deposit is characterized by the presence of antimony in the form of Sb2S3. During the calculations of the equilibrium composition, the optimal conditions for low-temperature roasting were selected. It was found that under these conditions, the dissociation of higher sulfides occurs, arsenic goes into the form of trisulfide (As2S3) and some of the iron goes into the form of sulfate (FeSO4). All this suggests that the process of low-temperature roasting allows to open the refractory concentrate and get a cinder, the further processing of which will not cause special problems: the non-volatile form of arsenic trisulfide will not cause complications when cleaning exhaust gases, and iron sulfate will simplify further leaching processes. © Published under licence by IOP Publishing Ltd.