Arsenic rejection from lead concentrate using aluminosulfate

• The separation process of arsenic from lead concentrate involves the pulp oxidation process and the application of an arsenic depressant.
• Aluminosulfate depresses the arsenic of lead concentrate oxidized with H2O2.
• Ettringite is formed on the surface of arsenopyrite depressed with aluminosulfate during flotation.

Arsenic in base metal sulfide ores is highly penalized owing to high costs for its control in metallurgical processing. This study developed a flotation process involving additions of pH modifier and arsenic depressant, and oxidation scheme for the removal of arsenic from lead concentrate containing arsenopyrite. The addition of Na2CO3 as pH modifier caused to produce high lead concentrate, assayed at about 65.2% Pb and 0.8% As. The lead concentrate containing 80.7% Pb and assaying 0.25% As could be obtained with the addition of aluminosulfate as an arsenic depressant to the oxidized lead concentrate.