Copper recovery from iron contg sulphidic ore or concentrate - by oxidising weakly acidic extract to ppte ferric hydroxide and sulphur

摘要

Copper is extracted from ores or concentrates contg. Cu and Fe by dispersing the ore or concentrate (pref. a sulphidic ore, esp. chalcopyrite, malachite or azurite) in an electrolyte soln. contg. Cl- ions, heated to a temp. between 50 degrees C and the b. pt. of the soln.; and introducing finely disposed air or another O2-contg. gas into the suspension whilst maintaining the pH at 1.5-7.0, whereby iron is pptd. as Fe(OH)3 whereas copper remains in the soln. as Cu2+ ions. In the case, when a sulphidic ore or concentrate is used, elemental sulphur is pptd. The pH is maintained with in the above range by addition of HCl or by anodic oxidation of water. Copper is subsequently recovered from the soln by chemical displacement with iron or by electrolytic deposition. The one-stage process is less expensive than the conventional multistage process. There is no pollution of the surrounding atmos. The process is carried out at atmospheric press. (Fe(OH)3 and elemental sulphur are valuable by-products.