| 摘要 |
<p>A process for the extraction of copper from a sulphide copper ore or concentrate comprises subjecting the ore or concentrate to pressure oxidation in the presence of oxygen and an acidic chloride solution to obtain a resulting pressure oxidation filtrate and an insoluble basic copper sulphate salt. The pressure oxidation is conducted in the presence of a source of bisulphate or sulphate ions, such as sulphuric acid. The amount of the sulphate source added contains at least the stoichiometric amount of sulphate ions required to produce the basic copper sulphate salt less the amount of sulphate generated in situ in the pressure oxidation. In a particular embodiment, the pressure oxidation is carried out at a predetermined H<+>/Cu ratio so that the pressure oxidation filtrate contains a major portion of the copper in the ore or concentrate and the basic copper salt contains a minor portion of the copper in the concentrate. The invention further provides for the selection of the H<+>/Cu ratio according to the grade of the ore or concentrate, the value of the ratio being selected with increasing magnitude compared with decreasing grade of the ore or concentrate. In a further embodiment, the basic copper salt is dissolved in a subsequent atmospheric leaching stage. A concentrate copper solution, which is suitable for electrowinning, is obtained by means of solvent extraction. The process also provides for the extraction of zinc and nickel from the ore.</p> |
