The relationship among pyrite fine grinding by stirred ball mill and tumbling ball mill, the properties of the product and the flotation behavior

Abstract

With the increasing complexity of ore texture and refinement of mineral dissemination size, fine grinding has become increasingly necessary. Different types of mills produce grinding products that affect flotation performance differently. Therefore, the relationship among fine grinding mills, the physical and chemical properties of the products, and subsequent flotation performance still needs to be established and understood. In this study, two distinct types of mills, stirred ball mill (SBM) and tumbling ball mill (TBM), with different grinding mechanisms, were employed for pyrite fine grinding. The results of grinding kinetics indicated that both SBM and TBM can produce fine particles, with SBM requiring much less time. When the grinding fineness of both was 90 % passing 25 µm, compared to TBM products, the pyrite obtained using SBM exposed more (2 0 0) surface, had lower particle roundness and more elongated shape. Furthermore, the pyrite surfaces treated with SBM contained lower concentrations of hydrophilic components, Fe-O/OH, O²⁻, and SO₄²⁻, and more hydrophobic components, S²⁻, S₂²⁻, and S_n²⁻/S⁰. Consequently, the change of the chemical and physical properties of the products in SBM caused a 10 % increase in the flotation recovery of fine-ground pyrite compared to TBM. The results of this study provide a fundamental understanding for industry mill selection and subsequent flotation performance.