Reverse Flotation of Magnesite by Dodecyl Phosphate from Dolomite in the Presence of Sodium Silicate

Abstract Magnesite and dolomite are two salt‐type minerals. They show similar flotation behavior due to the same crystal structure, similar chemical composition, and high solubility. It is difficult to achieve effective flotation of magnesite from dolomite in a single stage. The present study was performed to develop a new and better flotation scheme for magnesite from dolomite. The flotation tests show that there exists a significant difference in flotability between magnesite and dolomite when dodecyl phosphate synthesized with dodecanol, phosphorus oxychloride, and other chemicals is used as collector. Modifiers are necessary to improve flotation selectivity. It was found that sodium silicate selectively depressed magnesite at a pH of 4.5 to 7.5. The flotation mechanism was investigated by characterizing surface electrical properties and measuring the adsorption density of the reagents on magnesite and dolomite.