Selective adsorption of carbonate ion on quartz in the presence of calcium ion from calcium minerals

The objective of this study was to determine the adsorption of carbonate ions on quartz mineral by using the following mineral binary mixtures: fluorite - quartz, scheelite - quartz and calcite - quartz. Zeta potential of each mineral was determined by measuring the electrophoretic mobility, and the solubility of the calcium minerals by measuring total calcium concentration in solution. The results indicated that, for different binary mixtures and for a conditioning time of 30 minutes, the total concentration of calcium ion in solution is approximately the sum of the calcium in the individual suspensions. It was also observed that the carbonate ion markedly modified the zeta potential of quartz, while this potential is slightly modified in the calcium minerals. It is concluded that the carbonate ion is selectively adsorbed on the quartz mineral. Also, its presence favors the efficiency in the separation of the quartz from ores bearing fluorite, scheelite, and calcite minerals, in both flotation or flocculation processes.