Leaching Coarse Native Copper Ore With Dilute Ammonium Carbonate Solution.
Groves-RD; Jeffers-TH; Potter-GM
Solution Min Symp 103D AIME Ann Mtg 2/74 Am Inst Min Metal & Petrol Eng Pp381-89 :9 pages
Experiments on ammonium carbonate leachng of native copper ores crushed to 1-inch size showed that in 30 days 55 percent of the copper was extracted from 0.7 percent copper conglomerate-type ore, and 85 percent was extracted from 2.1 percent copper amygdaloid-type ore. Cupric ions were not necessary to initiate leaching, and dilute solution containing only 2.2 Grams per liter nh3 and 1.9 Grams co3--was a suitable solvent. Copper was recovered from the leach liquor by solvent extraction and electrolysis of the strip solution. Cyclic testing of the leach-solvent extraction- electrolytic procedure is in progress on a 6-ton charge of minus 12- inch conglomerate-type ore assaying 2.2 percent copper. Oxygen is metered to the closed leach vessel as required by the leaching reaction. Initial copper dissolution was much slower than from minus 1-inch ore, but the leaching rate then markedly improved.
Solution Min. Symp., 103D AIME Ann. Mtg., 2/74, Am. Inst. Min., Metal. & Petrol. Eng., Pp381-89