Effect of pre-oxidation on copper-lead bulk concentrate flotation separation with sodium polyacrylate as galena depressant

Abstract

In this work, adsorption and flotation tests were performed to investigate the suitability of sodium polyacrylate (PAAS) as a galena depressant in a Cu-Pb separation system and the effect of pre-oxidation on it. Adsorption studies show that PAAS effectively adsorbed on galena in the pH range 8–9, during the interaction between (R-COO-)n and Pb(OH)+. However, the adsorption of PAAS on chalcopyrite was approximately 6.8-fold less than on galena. Insoluble lead oxides formed on the galena surface after pre-treated with hydrogen peroxide (H2O2), which promoted the adsorption of Pb(OH)+ on galena, thereby providing additional adsorption sites and enhancing the adsorption of PAAS on galena. For Cu-Pb bulk concentrate containing 3.03 % Cu and 62.32 % Pb, the use of PAAS combined with H2O2 as a galena depressant for flotation separation yielded a Cu concentrate with 28.02 % Cu and a recovery of 82.56 %, containing 5.54 % Pb. The separation efficiency reached 65.44 %, comparable to that of potassium dichromate (K₂Cr₂O₇, 68.84 %). Compared with traditional chromium-containing depressants, this work avoids the pollution of metal chromium to humans and the environment, and provides a better reference for similar research.