Effect of sodium metabisulfite and slaked lime on the floatability and surface properties of chalcopyrite

In the flotation of complex copper ores containing chalcopyrite in seawater, sodium metabisulfite (SMBS) has been widely used as a pyrite depressant. Here, calcium ions in seawater or in process water because of pH control using lime (CaO) or slaked lime (Ca(OH)(2)) can affect the floatability of chalcopyrite. However, the effect of SMBS on the floatability of chalcopyrite in the presence of calcium ions is unknown. Therefore, the current study investigated the flotation behavior and surface properties of chalcopyrite after treatment with SMBS in the absence and presence of Ca(OH)(2). The flotation experiments demonstrated that both SMBS treatment and the addition of Ca(OH)(2) exhibited a depressing effect on the natural floatability of chalcopyrite. This depressing effect of SMBS and Ca(OH)(2) on the floatability of chalcopyrite was significantly decreased in the presence of potassium amyl xanthate (PAX). However, the combination of SMBS treatment and Ca(OH)(2) formed calcium sulfite (CaSO3) on the surface of chalcopyrite, which significantly reduced the recovery of chalcopyrite from 97% to 66% when in the presence of PAX and at a pH of 9.

Automated summary

The flotation behavior and surface properties of chalcopyrite after treatment with sodium metabisulfite (SMBS) in the presence of calcium ions were investigated. The results showed that both SMBS treatment and the addition of calcium hydroxide (Ca(OH)(2)) had a depressing effect on the floatability of chalcopyrite, which was reduced in the presence of potassium amyl xanthate (PAX). However, the combination of SMBS treatment and Ca(OH)(2) resulted in a significant decrease in the recovery of chalcopyrite.