Effect of Surfactants and Carbon Nanomaterials on the Electroflotation Extraction of the Disperse Phase of Cobalt Hydroxides

Abstract

The effect of surfactants and carbon nanomaterials (CNMs) on the electroflotation extraction of the disperse phase of cobalt(II) and (III) hydroxides at pH 6 and pH 10 was studied. It is shown that at pH 6 in the absence of surfactants, the efficiency of cobalt extraction in various electrolytes is low and does not exceed 15–25%. In the surfactant–CNM–electrolyte system, the degree of extraction α increases in the chloride, nitrate, and sulfate solutions compared with the solutions containing no surfactants. The electroflotation extraction of cobalt was more efficient at pH 10: α reached 80–96% in the absence of surfactants, 70–97% in the surfactant–electrolyte system, and 60–97% in the surfactant–CNM–electrolyte system. The optimum conditions of the electroflotation extraction of cobalt hydroxides from solutions containing various inorganic electrolytes were determined. The effect of the sodium chloride content on the degree of cobalt extraction at pH 6 was studied. When the NaCl concentration increased from 0 to 10 g/L, the efficiency of cobalt extraction increased to 92%; when the flocculant was added and an additional stage of filtration was used, cobalt was extracted almost completely.