Inhibition performance and adsorption of polycarboxylic acids in calcite flotation

Abstract

As a common gangue mineral, the inhibition of calcite is very important to enrich the valuable minerals by flotation. With the increasing complexity of mineral properties and higher requirements for environmental protection, developing a newly eco-friendly depressant for calcite flotation is necessary. In this study, the effects of polyaspartic acid (PASP), polyepoxysuccinic acid (PESA), and hydrolytic polymaleic anhydride (HPMA) on the flotation performance of calcite using sodium oleate as the collector were investigated through flotation experiments. The results showed that all the three depressants exhibited strong inhibition to calcite, and the inhibition capabilities decreased in the order of PASP > HPMA > PESA. The results of zeta potential measurement, contact angle measurement and X-ray photoelectron spectroscopy indicated that the adsorption of sodium oleate on calcite surface was greatly decreased as the addition of the depressant. To investigate the inhibition selectivity, three depressants were used in fluorite flotation, and the results suggested that sodium oleate could still adsorb on fluorite surface in the presence of PASP. The flotation separation of fluorite from calcite could be therefore realized with PASP on the basis of the best selectivity among the three depressants.