Scholarly record

EFFECT OF SODIUM CHLORIDE ON COPPER BIOLECHING FROM SULFIDE MINERALS AND CONCENTRATES

А. Г. Булаев

Abstract

Pyrometallurgical processing of arsenic containing polymetallic ores and concentrates poses a problem due to the emission of toxic gases. Hydrometallurgical methods including bioleaching may be used as alternative approach to treat this type of mineral raw material. To perform effective hydrometallurgical processing of mineral raw materials, factors affecting leaching efficiency should be studied. The goal of the present work was to study the effect of sodium chloride on copper bioleaching from arsenic-containing minerals and chalcopyrite as well as from arsenic-containing polymetallic concentrates. Chalcopyrite (CuFeS2), enargite (Cu3AsS4), and tennantite (Cu12As4S13) as well as two copper-zinc concentrates containing arsenic were subjects of the study. First concentrate contained 6.2% of copper, 7.3% of zinc, and 1.7% of arsenic. Second concentrate contained 16% of copper, 5.3% of zinc, and 1.36% of arsenic. Pyrite, chalcopyrite, tennantite, and sphalerite were the main minerals of the concentrates. Bioleaching was performed using mixed culture of acidophilic microorganisms oxidizing ferrous iron and sulfur compounds (Sulfobacillus thermosulfidooxidans SH-1, Acidithiobacillus caldus MBC-1, and Acidiplasma sp. MBA-1). The experiments were carried out in flasks with 100 mL of mineral nutrient medium containing salts of nitrogen and phosphorus supplemented with 0.02% of yeasts extract as carbon source and 2 g of milled minerals (P100 75 ?M) or concentrates on a rotary shaker at 50°C for 30 days. In one variant of the experiment, nutrient medium was supplemented with 100 mM NaCl to evaluate the effect of sodium chloride on bioleaching. In control variant, NaCl was not added to the medium. It was shown that NaCl addition increased rate of copper extraction from chalcopyrite but led to the decrease in copper extraction from enargite and tennantite. Copper extraction rates from chalcopyrite, enargite, and tennantite in control and in the experiments with NaCl addition were 25 and 33%, 14 and 5.9%, and 18 and 13%, respectively. Sodium chloride addition made it possible to increase zinc extraction rate from the concentrates. Zinc extraction rates from the first and second concentrates increased from 71 to 84% and from 69.8 to 100%, respectively. In the same time, copper extraction from the concentrates was less affected by sodium chloride addition. Copper extraction rates from the first and second concentrates in control and in the experiments with NaCl addition increased from 44.3 to 44.8% and from 51.8 to 59.1%, respectively. Thus, it was shown that sodium chloride addition makes it possible to increase rates of chalcopyrite and sphalerite leaching that is well-known fact. In the same time, sodium chloride addition did not increase copper extraction rate from arsenic containing minerals.

Publication Impact Profile

• Citations
• CrossRef - Citation Indexes: 3

• Captures
• Mendeley - Readers: 2

PLUMX see details

DOI resolver: doi.org/10.5593/sgem2019/1.3/s04.102

Publication details

Back to publication list