Beneficiation studies with a pyrite-pyrrhotite sample from Saladipura, Rajasthan

A 100 ton pyrite-pyrrhotite sample was received by NML from M/s Pyrites, Phophates and Chemicals Ltd., with a request to study the feasibility of producing a pyrite-pyrrhotite assayed 39% S, to be used in the fertiliser plant. The sample, as received, assayed 23% S with coarse grained pyrite and pyrrhotite were 93%-200 mesh (TSS) grind with 0.24 kg/tonne of potassium ethyl xanthate, 0.045 kg/tonne of pine oil and 3.0 kg/tonne of H2SO4 (pH 5.2-5.7). Under these conditions, concentrate obtained was 53.3% by weight assaying 40.5% S with 91.8% S recovery. Attempts to preconcentrate the ore by gravity methods did not yield encouraging results. Pilot plant tests were conducted under the optimum conditions and also studying the variables. Test results indicated that 85%-200 mesh (TSS) grind with 0.22 kg/tonne of KEX, 0.03 kg/tonne of pine oil and 3.0 kg/tonne of sulphuric acid along with reclamated water were the optimum conditions under which a concentrate weighing 48.5% and assaying 41.5% S with a recovery of 94.9% was produced. (P.D. Prasada Rao, C. Satyanarayana, K. Vijayaraghavan and G. P. Mathur, National Metallurgical Laboratory