METHOD OF ACQUIRING THE COPPER FROM THE SULPHIDE CUPROUS MINERALS

摘要

1404243 Recovering copper ANACONDA CO 6 March 1973 [7 March 1972] 10688/73 Heading C1A Copper is recovered from sulphidic minerals by leading a slurry of the minerals in aqueous solution containing ammonium sulphate and free ammonia in one, or sequentially in a series of closed leaching vessels at low pressure (<10 p.s.i.g.) at a temperature of 50-80‹ C., whilst recirculating oxygen bearing gas from above the slurry to below the surface thereof, vigorously agitating the slurry with a power input of 0À05 hp./cu.ft. of slurry and introducing fresh oxygen into the slurry, and withdrawing from the vessels a solution containing the copper complexed with the ammonia. Free ammonia may be added to at least the first of the vessels at a rate equal to its consumption, and the concentration of the ammonia may be correlated with the slurry temperature which gradually rises through the series whilst the pH decreases from about 10 to 9À5. The solution may be treated to recover the copper and form ammonium sulphate solution which may be recycled to the leachy. The copper containing solids residue may be subjected to a secondary leaching under substantially the same conditions as the initial leaching.