Oxidation of sulphide minerals-III determination of sulphate and thiosulphate in oxidised sulphide minerals.

A method has been developed to determine sulphate and thiosulphate in small amounts of the oxidation products of sulphide minerals. The sample is treated with ammonium sulphide solution to promote ion-exchange between sulphide ion and the sulphur-bearing anions of the oxidation products. Sulphate is determined alone and then all other sulphoxy anions are oxidized to sulphate and determined as such. The non-sulphate anions are reported as thiosulphate. The relative error is about 10% or less for 2 mg or more of sulphoxy anion. Although this method does not yield exact results with respect to sulphite or polythionates, a clearer understanding of the oxidation of sulphide minerals is now available.