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Electrochemical Interactions Between Mineral and Grinding Media and Their Effects on Flotation and Media Wear.
PhD Dissertation Univ Minnesota-Minneapolis Contract No G1125149-2702 (G1125149-2702):155 pages
This report describes the electrochemical nature of mineral grinding media interactions in the wet grinding of one-and two-sulfide mineral ores with regard to the corrosive wear of the media and the flotation behavior of the minerals. Pyrite and pyrrhotite and mild steel, high carbon forged steel, and austenitic stainless steel were used to represent the sulfide minerals and the grinding media, respectively. Rest and combination potentials, galvanic currents, and polarization behaviors under abrasive and nonabrasive conditions were correlated with data from marked ball wear tests, hallimond tube flotation tests, and with scanning electron photomicrographs and energy dispersive x-ray spectra. Corrosion currents obtained by superposition of polarization curves of sulfide mineral grinding media systems were in good agreement with corrosion currents estimated from ball wear data. Freshly abraded metallic debris particles generated by abrasive wear of the grinding media lowered the corrosive wear of the media by affecting the electrochemical behavior of the minerals, particularly for a magnetic mineral such as pyrrhotite. The adverse effect of mineral-grinding media interactions on the flotabilities of pyrite and of pyrrhotite in the single-mineral systems was partially reversed in a two-mineral grinding media combination. A parallelism was found between these flotability changes and the galvanic behaviors of the minerals in the two- and three-electrode systems.
Ph.d. Dissertation, Univ. Minnesota-Minneapolis Contract No. G1125149-2702
Page last reviewed: April 12, 2019
Content source: National Institute for Occupational Safety and Health Education and Information Division