Investigation into the impact of Mn2+ and its interaction with calcite in the flotation of rhodochrosite
The unavoidable Mn 2+ ions in pulp were considered in the flotation of rhodochrosite, and its effect and relative interaction mechanism on the floatability of calcite served as a typical gangue mineral were investigated through microflotation tests, zeta potential measurements, SEM-EDS detection, solution chemistry calculation, adsorption experiments, FTIR and XPS analyses. There exhibited a good separation performance of rhodochrosite against calcite with OHA collector, but in the presence of Mn 2+ ions, the floatability of calcite was closed to rhodochrosite within a pH of 8.0–10.0, which resulted in the separation difficulty between them. As evidenced, the surface of calcite could be modified by Mn 2+ ions, its isoelectric point shifted positively from 8.91 to 10.06, and Mn 2+ species detected on calcite surfaces were in close proximity to rhodochrosite. It indicated that MnCO 3 precipitates were generated on the surface of calcite. After modified by Mn 2+ , the calcite surface became more active and obviously increased the adsorption amount of OHA. It was verified from zeta potential and XPS analyses that Mn species on the surface of calcite were active sites for OHA adsorption, likely the hydroxamate group of OHA collector chelated with Mn species to form hydrophobic compounds. As a result, Mn 2+ ions in pulp would reduce the flotation selectivity of rhodochrosite from calcite, thus it is necessary to eliminate the disadvantage of Mn 2+ for strengthening flotation.
危险品化学品经营许可证（带存储）