INTERACTIVE EFFECTS OF THE SULPHITE ION, pH, AND DISSOLVED OXYGEN ON THE FLOTATION OF CHALCOPYRITE AND GALENA FROM BLACK MOUNTAIN ORE.
At low additions of sulfurous acid as the pH regulator, flotation rate increased with increasing dissolved oxygen. The recovery of chalcopyrite dropped below a pH value of about 6. 5 at 25 p. p. m. of dissolved oxygen and below a pH value of about 6 at a dissolved-oxygen concentration of 8. 2 p. p. m. The rest and pulp potentials indicated that dixanthogen is the dominant species formed on chalcopyrite surfaces during flotation with sodium ethyl xanthate. The same species might have formed on galena surfaces in the pulp after the ore had been milled under nitrogen. Increased additions of sulfurous, sulfuric, and hydrochloric acids increased the rest potentials while the addition of sodium sulfite decreased these potentials.