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ArticleName Simulations and studies of the influence of calcium ions on molybdenite floatability
DOI 10.17580/or.2019.03.04
ArticleAuthor Pestryak I. V., Morozov V. V.

National University of Science and Technology (NUST) MISIS (Moscow, Russia):

Pestryak I. V., Associate Professor, Candidate of Engineering Sciences, Associate Professor,
Morozov V. V., Professor, Doctor of Engineering Sciences, Professor,


In conditions of closed water circulation, the floatability of molybdenite decreases. Similarly, the recovery of molybdenite into the bulk concentrate is reduced when dosing lime in the grinding operation. To establish the reasons for the decline in technological indicators, the influence of calcium ions on the state of the surface and floatability of molybdenite in the conditions of grinding and collective flotation was investigated. Thermodynamic calculations show the possibility of formation under grinding conditions (pH = 7.2–8.5) on the surface of the calcium molybdate mineral. The formation of insoluble compounds is indicated by a decrease in the oxidation rate of the mineral with an increase in the concentration of calcium and molybdenum ions in the aqueous phase. X-ray spectroscopic studies have shown that an excess of calcium ions leads to chemical interaction and fixation of calcium compounds on the surface of molybdenite. In the pH range from 7.6 to 8.5, calcium molybdenum prevails, and in the pH range from 8.5 to 10.3 calcium carbonate prevails It has been established that with an increase in the pH of the medium to 10.3, characteristic of the flotation process, calcium molybdate becomes calcium carbonate, which hydrophilizes the surface of molybdenum and reduces its floatability. To prevent the negative influence of calcium and molybdat ions on the flotation of molybdenum, it is proposed to use water sources with a reduced concentration of these components. It is possible to reduce the formation of hydrophilic coatings on the surface by reducing the rate of oxidation of molybdenum or to prevent the formation of calcium molybdat on it by regulating the pH of the aqueous phase.

keywords Copper-molybdenum ores, molybdenite, calcium ions, thermodynamic modeling, hydrophilization, grinding, flotation

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