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Status Refractory gold ore processing technology in China. These are difficult to recover gold ore or gold concentrate using conventional cyanidation. Most carbon-containing arsenic and other harmful elements, must be recovered by cyanidation of gold or other methods to undergo various pre-treatment process. The typical representative of the roasting pretreatment is the Hunan Golden Cave Gold Mine. The arsenic-containing gold concentrate produced by it is subjected to two-stage roasting: the first stage is calcined under anoxic conditions, the arsenic in the flue gas is recovered in the form of chalk, and the comprehensive recovery rate is 99.9%; the second stage is desulfurization in an oxidizing atmosphere. 6% to 10% of sulfur in the flue gas meets the acid-making conditions, and the absorption rate is over 90%. The produced cyanide leaching rate can be increased from 60% to 70% of a calcination to about 93%. The ore has been continuously produced for several years using a method of roasting and arsenic sulfide. Now, after the test by the Beijing Research Institute of Nonferrous Metals, a 20t/d treatment plant has been built. The two-stage roasting and cyanidation process can provide typical production experience for China. In addition to the Golden Cave, there are four smelters in the country that use the roasting-cyanide process. The total production capacity is about 1100t/d. However, they all adopt the -stage roasting-cyanide method, which cannot meet the technical and environmental requirements for the gold concentrate containing complex arsenic.
After the "Ninth Five-Year" scientific and technological research, the hot-pressure oxidation process has completed a large number of small tests and expanded continuity tests, which have provided conditions for industrial production. The Changchun Gold Research Institute cooperated with the Nuclear Industry Beijing Metallurgical Research Institute to study the ore of the Minjiang Gold Mine in Jilin Province, and effectively oxidize and decompose the gold-bearing sulfide by alkaline hot-pressure oxidation-cylinder rapid cyanidation gold extraction process. The gold leaching rate is increased from 47% to over 92% during direct cyanidation. The temperature and pressure of the oxidation process are lower than those of foreign technology, which is more in line with China's national conditions. In 2002, the Jinfengling Gold Mine in Shandong Province has established an acid hot-pressure oxidation-gold extraction workshop. Production capacity of 100 t / d gold concentrate, currently under commissioning.
Bacterial oxidation-cyanide gold extraction process is also a typical result of the “Ninth Five-Year†scientific and technological research. The result has been cooperated by Shandong Yantai Smelter and Changchun Gold Research Institute, and the first bio-oxidation technology has been successfully built in China. The 50t/d production scale of the bacterial oxidation-cyanide carbon slurry process gold-free demonstration plant with independent intellectual property rights was officially put into operation in December 2000 and passed the appraisal and acceptance of the Ministry of Science and Technology. Continuous production for many years, the current technical indicators are stable, gold concentrate re-grinding to -0.038mm accounted for 90%, oxidation temperature 40 ~ 50 ° C, oxidized pulp concentration of 18%, leaching time 6d process conditions, gold leaching of arsenic-containing gold concentrate The rate of more than 95% has created a precedent for the use of bio-oxidation of arsenic-containing gold concentrates in China and cyanide gold extraction process. Since then, Liaoning Fengcheng is currently building 100t/d of this kind of gold extraction plant, Shandong Laizhou gold smelting plant cooperates with Australia and South Africa, and a full set of imported equipment and technology is under construction. 200t/d arsenic-containing gold concentrate bacteria oxidation-cyanide Gold workshop. Provide more technology and experience for our country. It is expected that in the near future, the arsenic-containing gold concentrate cyanidation process will gradually become a conventional technology. It is a bright future for the development of arsenic-containing and difficult-to-treat minerals with hundreds of tons of metal in various provinces such as Yunnan, Guizhou and Guangxi.
A simple and effective pretreatment method for arsenic-containing carbonaceous gold concentrates. The gold ore of the old gold field in Anxi, Gansu, has a direct leaching rate of cyanide gold of only 13.9%. After flotation, gold concentrate grade gold is 79.8g/t, silver is 52.9g/t, arsenic is 5.6%, sulfur is 13.3%, carbon is 4.24%. After ultrafine grinding, the gold cyanide leaching rate increased to 53.78%, and after cyanidation, the cyanidation reached 71.7%, and the leaching residue containing gold more than 20g/t was difficult to obtain satisfactory results. The precious metal smelting plant of Ximai Mining Company adds a chemical material C which is very easy to obtain locally during roasting. It utilizes the characteristics of high-energy self-ignition of sulfur in gold concentrate to make it fully combusted with C. The gold leaching rate greater than 93% can be obtained. The process roasting equipment is simple, the tail gas is easy to be recycled, the environmental pollution is small, the investment is small, the effect is quick, and it is suitable for the promotion and application of small and medium mines.
A copper-based gold gold, silver, lead and zinc polymetallic sulfur vulcanization deposits associated epithermal fluid, a high degree of oxidation mud volume, higher copper sulfur arsenic content, fine particles of gold, gold difficult process Ores It has a 70t/d flotation plant to produce copper concentrate and sulfur concentrate. The mine commissioned the Southern Metallurgical Institute to carry out experimental research, and finally determined the mixed flotation-mixed copper-sulfur separation-sulfur re-milling-thiourea carbon leaching gold scheme. The test results are satisfactory, and the gold content in the ore is 5.05g/t, silver is 85.95g/t, and copper is 1.71%. It has achieved a good recovery rate of 79.11% gold, 65.49% silver and 86.32% copper, indicating the direction for future production.Forgings are produced by 1000T+1600T electric screw press machine, using medium frequency induction heating and full automatic operating by robot , and Japan MANYO1300T walking beam forging equipment for high quality assurance, has lower allowance, advantages of materials saving and better metal streamline.
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