Study On The Pre-oxidizing Treatment Of Carbonaceous Gold Ore By Chlori-oxidition Roast

In present, with the depletion of oxide ores throught out the world, refractory gold ores are becoming of increase importance to the mining industry. The poor leach behavior of these ores is attributed to the presense of sulphide minerals and carbonaceous matter. Carbonaceous material in sulphide ores has been shown to act like activated carbon and to adsorb solubilised gold cyanide as a bulk phenomenon.Hence much research has been concentrated on the characterization of carbonaceous matter, Apart from carbonates, Carbonaceous material in refractory gold bearing ores consists of i) a native carbon component acting like activated characoal and able to adsorb gold cynide from solution .ii) a high molecular weight hydrocarbon mixture which appears not to interact directly with gold, and iii) a "humic acid " like component containing functional groups capable of complexing with soluble gold .Various methods have been used to deactivate this carbonaceous matter, e. g. chlorination roast and carbon-in-leach (CIL). A available Chlorination mathod because of high cost and toxicity has been confined. Roasting is a common mathod because of simple, applicable and so on. But it needs a high temperature and complex process. CIL is also a common process alternative in which activated carbon is used to compete with carbonaceous matter for gold cyanide adsorption. However the CIL process has much less effect on highly preg-robbing ores containing high concentrations of very fine carbon, carbonaceous preg-robbing may be inhibited by the addition of blinding chemicals such as diesel kerosene and heavy machine oils to the leach circuit of a plant. So we put forward a new method- Chlori-oxidition Roast. This mathod can make carbonaceous decompounded, and improvements in gold recoveries have been achieved in cyanidation of residue.First, study on the pre-oxidizing treatment of carbonaceous matter in carbonaceous gold ores by Chlori-oxidition roast. Found that the dosage of Chlor-medicament temperature and oxygen overpressure have an advantage on the decompoundation of carbonaceous matter. When the parameter of temperature 380℃,the dosage of chlori-medicament 20% and oxygen overpressure 0.028m~3/h ,there are only 1.93% that carbon on the residue, and found that the content of sulphides minerals have an impact on the decompounddation of carbonaceous matter. The lower the content of sulphides minerals, the worse the decompoundation of carbonaceous matter.Whereafter, study on the pre-oxidizing treatment of sulphides minerals in carbonaceous gold ores by Chlori-oxidition roast. Found that the treatment have an advantage on pre-oxidited sulphides minerals. So this method can pre-treatment sulphides minerals.Last, this is an available method for carbonaceous gold ores and sulphides minerals. Wishing they have a good prospect.