| 摘要 |
A process of reducing cupric oxide to cuprous oxide comprises heating the cupric oxide with a sulphur containing reducing agent (sulphur or sulphide of copper, iron, zinc, tin or lead) in the presence of an alkali metal, or an alkaline earth metal, chloride in a protective atmosphere (e.g. steam), the temperature being 250-750 DEG C. The leaching of copper from ores using a copper ammonium carbonate leach solution in the presence of ammonia is referred to, the reaction going according to the following equations: Cu + Cu(NH3)4++ + 2HCO31--> Cu2(NH3)4++ + 2HCO31 the product is then decomposed by heat as follows: Cu2(NH3)4++ + 2HCO31--> Cu2Oppt+ 4NH3 + 2CO2 + H2O The preparation of copper sulphide is also referred to, there being two reactions which occur simultaneously and may be represented by the following equations: 2Cu + S + C + O2 --> Cu2S + CO2 Na2SO4 + 2C --> Na2S + 2CO2. It is stated that this mixed sulphide, which has a lower melting point than copper sulphide alone, may be used in the process of the invention.ALSO:A process for preparing copper from cupric or cuprous oxide comprises heating the oxide with a sulphur containing reducing agent (sulphur or sulphides of iron, copper, zinc, lead or tin) in the presence of an alkali metal, or alkaline earth metal, chloride in a protective atmosphere (e.g. steam). The temperature may be 250-750 DEG C. The preparation of cuprous sulphide, the leaching of copper from ores using a copper ammonium carbonate leach solution and the reduction of cupric oxide to cuprous oxide by the method of the invention is also referred to (see Division C1). |
