Acid Leaching of Malachite Ore and Separation of Cu(II) by di-(2-Ethylhexyl) Phosphoric Acid and Tributyl Phosphate in Acetate Buffer Solution

摘要

Copper extraction from malachite ore by leaching and solvent extraction was examined. The leaching experiments were performed by sulphuric acid, hydrochloric acid and mixed reagent system. The iron impurity in the leach liquor had adverse effects on the copper extraction, therefore, iron separation from sulphate and mixed sulphate/chloride leach liquors was done using Tri-n-butyl-phosphate (TBP) and methyl-iso-butyl-ketone (MIBK). This indicated that it was possible to remove more than 95 % of iron content using 70 % TBP and 30 % MIBK. After iron removal, copper extraction was performed for various temperatures at different pH values from aqueous acetate buffer solutions with di-(2-ethylhexyl) phosphoric acid 20 % (V/V) dissolved in hexane. The results indicated that acetate ion had the maximum effect at pH 4.5. Thus, it could be mentioned that pH was the most important factor and that it was possible to recover more than 90 % of the copper from leach liquor under the optimum leaching condition.