Separation of copper-sulfur using sodium polyacrylate as pyrite depressant in acidic pulp: Floatability and adsorption studies

Abstract

This study aimed to investigate the suitability of sodium polyacrylate (PAAS) as a pyrite depressant in a Cu-S separation system through flotation and adsorption experiments. Micro-flotation tests showed that chalcopyrite was selectively separated from pyrite using PAAS as a pyrite depressant in the pH range 2–4. A satisfactory separation effect, a copper concentrate with 30.02% Cu and a recovery of 94.16% was obtained in artificial mixed minerals tests. Adsorption studies showed that PAAS selectively adsorbed on pyrite in the pH range 2–4, while the adsorption on chalcopyrite was weaker, about 6.6 times lower than that on pyrite. PAAS adsorption on pyrite occurred through the interaction between (R-COO−)n and Fe(OH)n(3−n)+ at the solid/liquid interface. Oxidation pretreatment promoted the adsorption of Fe(OH)n(3−n)+ on pyrite, thus providing additional adsorption sites for PAAS and enhancing the adsorption of PAAS on pyrite. After PAAS adsorption, the weak floatability of pyrite in the presence of xanthate was due to the strong hydrophilicity imparted to pyrite by PAAS rather than hindering xanthate adsorption on pyrite.