Influence of grinding conditions on the pulp chemistry and flotation of oxidised pyrite

The influence of grinding conditions on the pulp chemistry of oxidised pyrite and its subsequent flotation behavior was studied in this paper. The oxidised pyrite particles were ground with forged steel or 30% chrome steel either in atmosphere or in a nitrogen-rich environment in a Magotteaux Mill (R). The in-situ pulp chemistry (i. e., dissolved oxygen, Eh, pH) was measured during grinding. The amount of iron and sulfur oxidation species in the solid and aqueous phases of the grinding slurry was determined using the EDTA (ethylene diaminetetra acetic acid) extraction technique. The flotation recovery of the dry grinding products and the grinding discharge in the absence and presence of a collector was determined. The results show that the flotation recovery of the ground samples relies on both the surface chemistry of the pyrite particles and the pulp chemistry of the discharge, which varies greatly between different grinding conditions. Grinding with forged steel under atmospheric environment and grinding with 30% chrome steel in a nitrogen-rich environment created a suitable pulp chemistry or produced little iron oxidation species, which are found to be the optimal grinding conditions for pyrite flotation.

Automated summary

This paper studied the influence of grinding conditions on the pulp chemistry of oxidised pyrite and its subsequent flotation behavior. The results showed that both the surface chemistry of the pyrite particles and the pulp chemistry of the discharge had a significant impact on the flotation recovery of the ground samples, and different grinding conditions led to variations in these chemical properties.