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Mineral resources is an important natural resource for human survival, development, social and technological advances, ore sorting techniques are constantly evolving. The gold reserves the human continued exploitation and utilization of mineral resources, is to continue to decrease, and tend to be of \Therefore, adequate and reasonable development of gold resources, in particular, the comprehensive utilization of low-grade refractory gold, with important economic and social significance. Qinghai a gold mine for the low-grade gold mines, ore symbiotic relationship is complex, fine-grained disseminated the target mineral separation difficult mixing cyanide leaching the impurity minerals in the ore leaching adverse low leaching rate of gold. This gold mine spectroscopy, chemical multi-element analysis, the gold phase analysis, and for the nature of this ore, conducted a series of exploratory tests, the following conclusions: (1) the nature of the gold mine sample The results show that: the ore quartz vein type gold ore in the gold content of 2.76 (10-6), mainly in the form of native gold, in addition to a small amount of isomorphous gold. The natural gold mainly in the form of micro-fine grained exist main fissures and wrapped in gold, where fissures accounted for about 41.7% of the gold, wrapped in gold which exist in feldspar, or 30.83% of the total gold total. In addition, argillaceous there are a small number of parcels gold, accounting for 17.68% of the gold total. Isomorphous gold is mainly distributed in the metal sulfide, a grade of 13.2 (10-6), accounting for 9.57% of the gold total. (2) test were investigated grinding fineness help infusion of sodium cyanide concentration, leaching time and peroxide of hydrogen, bleach, lead nitrate, ammonium salt of cyanide leaching, especially several ammonium salt auxiliary role of the amount of gold cyanide leaching. (3) The test data showed that, due to the presence of soluble copper ore, gold cyanide process by the greater impact. In agitation leaching within the first five hours of impurity minerals consumed most of the free sodium cyanide solution, low leaching rate of gold. When impurities basic dissolved, the remaining sodium cyanide to the gradual dissolution of gold ore. (4) The test results show that the leaching effect of ammonia leaching - Cyanide Leaching of the gold mine. Ammonia added so that the pH of the slurry was increased, promoting the formation of a precipitate of copper hydroxide, and reduces the content of the copper ions in the solution; the synergistic effect of the Cu-CN-complex ion in the ammonia solution, to promote the dissolution of gold. (5) Considering the field of production, the nature of the ore and the economic costs and other factors, and ultimately determine the best conditions for the gold mine cyanide leaching: grinding fineness of 95% -200 mesh pulp density of 40%, pulp pH 10 - 11, sodium cyanide concentration of 12/24 hours, ammonia or ammonium chloride leaching time for help infusion is more appropriate, sodium cyanide and ammonia molar ratio of 1:2, the gold leaching rate was 87.5%, cyanide The amount of sodium is the preferred leaching results of the 1.53 kg / t of ore. (6) Description of a hydrogen peroxide bleaching powder and nitric acid, lead to strengthening the principle of the gold leaching process, focusing on the mechanism of ammonia cyanide gold extraction process and. Cyanide leaching process, caused by consumption of large quantities of sodium cyanide soluble copper ore, affecting the leaching of gold. Ammonia leaching - cyanide leaching technology to handle a variety of copper and gold is the most effective method, ammonia can effectively reduce the impact of copper on gold leaching process, reduce the amount of sodium cyanide gold leaching rate.
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