Performance of residual potato starch as depressant in the direct anionic flotation of phosphate ore

Abstract

The search for environmentally friendly reagents with high efficiency, high selectivity, and low cost has intensified in the mining sector in recent years. The use of depressants from alternative and renewable sources is an option to be considered. Thus, the purpose of this study was to evaluate the use of residual potato starch pulp (RPSP) generated by the food industry as a depressant in phosphate ore flotation by comparing its performance with that of commercial, waxy corn starch (CWCS), rich in amylopectin. To this end, eight flotation tests were performed in duplicate using the Denver mechanical cell. The results showed significant variations for flotation in the collector dosage and starch-type parameters. The increase from 150 to 350 g/t in the collector dosage promoted an approximately 18% increase in metallurgical recovery using 500 g/t of RPSP starch (an increase from 73.09% to 86.16%). The response optimization statistical tool showed that RPSP and collector dosages should be 500 and 226.77 g/t, respectively, to maximize the P2O5 content and metallurgical recovery. These results suggest that it is feasible to use RPSP in phosphate ore flotation, opening new fields of investigation regarding the use of more accessible and economical depressants.