Enhanced flotation separation of phosphate and dolomite using a new amphoteric collector

Abstract

Among the impurities present in phosphate ore, dolomite is the most difficult to remove. This is because dolomite and phosphate have similar chemical compositions and because the dissolved species of dolomite is adsorbed on the surface of the phosphate mineral. A new amphoteric surfactant was found to be a suitable collector for the separation of dolomite and phosphate. Flotation results showed that the new amphoteric collector had a high flotation selectivity for dolomite over a wide pH range. Studies on the flotation of francoIhe and dolomite in each other’ s supernatant demonstrated that the dissolved ions had little effect on the selectivity of the new collector. It was found, however, that the dissolved ions were detrimental to the flotation separation using sodium oleate as collector. From a mixture of francolite and dolomite containing 26.2% P2O5, a phosphate concentrate containing 35.2% P2O5 with a 90% recovery was obtained using 290 g/t of the amphoteric collector. The rejection of MgO was 81.41%.