| 摘要 |
<p>1484976 Copper recovery FREEPORT MINERALS CO 29 Jan 1975 [27 Feb 1974] 3846/75 Heading C1A [Also in Division C7] Copper is recoverable, as copper cathodes, from a copper bearing sulphide ore containing iron, e.g. chalcopyrite concentrate, by leaching an aqueous slurry of the ore at 350‹ to 450‹ F. under an oxygen partial pressure of 50‹ to 500‹ p.s.i. to dissolve the metals as their sulphates and form sulphuric acid and thereafter, at the above temperature and pressure conditions, reducing the acidity of the slurry to preferably between 10 to 20 g.p.l. of sulphuric acid by means of a neutralizing agent, e.g. hydroxide, oxide or carbonate of calcium, strontium or barium, to precipitate substantially all of the iron as Fe 2 O 3 (hematite); the treated slurry comprising an ore gangue and hematite solid phase and an acidic liquid phase of copper sulphate is then flashed to atmospheric pressure and subjected to solids/liquid separation, e.g. filtration, centrifuging or a thickener; the separated solids are freed from residual copper sulphate and sulphuric acid by washing and the wash liquor recycled to the autoclave; the separated liquid phase containing copper sulphate is cooled and the copper content electrowon to give copper cathodes. The spent electrolyte containing sulphuric acid and residual copper is treated with a sulphiding agent, e.g. hydrogen sulphide, ammonium sulphide, sodium sulphide, ammonium hydrosulphide, sodium hydrosulphide, potassium sulphide, or potassium hydrosulphide, to precipitate residual copper as the sulphide followed by thickening and recycling of the thickened copper sulphide slurry to the leaching step.</p> |
