I. Development status of copper hydrometallurgical technology at home and abroad Since 1968, about 50 leaching-solvent extraction-electrochemical plants have been designed, constructed and operated in the world, including 16 in the United States. In 2000, copper production reached 557,500 tons, accounting for 28% of its refined copper production. The largest Arizona MOrenci plant currently has an annual production of 258,300 tons. In 1980, Chile produced only 15,000 tons of copper by solvent extraction and electrowinning. In 2000, it has developed into the world's largest copper producer. There are 21 production plants with an annual output of 1,437,300 tons of copper, accounting for the total amount of refined copper. 51%. Wet copper immersion technology in Zambia, Peru, Australia, etc. has also developed rapidly in recent years. Now the solvent extraction-electrowinning process has been considered by the industry to be a mature, low-cost, low-risk technology. The copper produced by this process has reached 2.4 million tons in 2000, accounting for more than 20% of the world's copper production. The production of wet copper has accounted for 1/4 of the world's copper production. Since the 1960s, the production process has been applied, some of our research units were carried out research leaching (acid leaching, ammonia leaching, bacterial leaching namely biological metallurgy), extraction technology, extraction agent aspects. After the 1980s, a relatively complete leaching-extraction-electrowinning process was formed and applied in production. Since the 1990s, with the rapid development of international copper hydrometallurgical technology research and application, coupled with the increasingly severe impact of domestic copper production and market, copper hydrometallurgical new technology research has been included in the national "Nine-Five "Key scientific and technological research projects have effectively promoted and accelerated the research and promotion of copper hydrometallurgical technology in China. At present, a large-scale development and production of the Dexing copper ore waste rock (average copper content 0.09%) bacterial leaching-extraction-electrowinning test plant (annual production of 2000 t). Zijin Mining Company's copper sulphide leaching-extraction-electrowinning test plant (annual production of 1000 tons of copper). Zhongtiaoshan Copper Mine in situ acid leaching-extraction-electrowinning test plant (annual production of copper 500 t). Although hydrometallurgical technology has developed greatly in recent years, there is still a big gap compared with foreign countries, mainly because of the gap between leaching basic theory and industrialization technology, and the established industrial production plants are small in scale and low in output. Second, copper hydrometallurgy principle, process and ore suitability (1) China's copper resources and production profiles China's copper mineral resources are relatively lacking, and the quality is low, the quality is poor; large-scale mines are small, small and medium-sized mines are more; rich and rich mines, less rich ore; complex polymetallic ore, more single mines; more underground mines, less open pit mines. These characteristics make the selection difficult, especially for beneficiation . Due to the low grade of ore and complex mineral composition, the cost of ore dressing is high and the grade of concentrate is generally low, which makes it difficult for subsequent smelting. As far as fire smelting is concerned, although there are great improvements in the process and equipment, the production cost is generally higher than that of foreign countries, and there are still serious environmental pollution. The advantages of copper hydrometallurgy are investment and low production costs. According to reports, the investment in tons of copper produced by the fire method is about 65,000 yuan, while the investment in tons of copper in the leaching-extraction-electrowinning process is about 15,000 yuan. In fact, from the actual situation in China, the production cost per ton of copper in the Dexing pilot plant is 10,450.23 yuan, that in Zhongtiao Mountain is 8,000 yuan, and that in Zijin Copper Mine is 10,000 yuan. If the scale of production is further expanded, production costs will fall. (2) Principle of copper hydrometallurgy 1. Principle of leaching of copper oxide ore Common copper oxide minerals are mainly malachite, chrysocolla, cuprite, and natural copper. Under the action of the leaching agents H 2 SO 4 and Fe 2 (SO 4 ) 3 , as long as the content of the highly alkaline gangue in the ore is not high, a better leaching effect is generally obtained. The chemical reactions that occur during the leaching process are: Malachite Cu 2 (OH) 2 CO 3 +2H 2 SO 4 =2CuSO 4 +CO 2 +3H 2 O Chrysocolla CuSiO·2H 2 O+FL 2 SO 4 =CuSO 4 +SiO 2 +(n+1)H 2 O Copper ore Cu 2 O+2H + =Cu 2+ +Cu+H 2 O Azurite Cu(OH)2·CuCO 3 +2H 2 SO 4 =2CuSO 4 +CO 2 +3H 2 O 2. Leaching principle of copper sulfide ore For copper sulfide ore, bio-oxidized copper is one of the most studied, fastest-growing and best-seeing technologies. Bioleaching microorganisms currently used primarily ferrous oxide and Thiobacillus thiooxidans. They can survive in extreme environments with high acid and heavy metal concentrations below 35 °C. The mechanism of bacterial oxidative leaching is generally two kinds: the direct action mechanism of bacteria adsorbing to the surface of minerals directly interacting with minerals to dissolve minerals: Fe 2+ released by mineral dissolution is oxidized by bacteria into Fe 3+ , Fe 3+ As an indirect or chemical mechanism of oxidation of oxidized sulfide ore. (1) Bacterial leaching of chalcopyrite The chalcopyrite can be oxidized to FeSO 4 and S in the presence of acid and Fe 3+ . The reaction is as follows: Cu 2 S + 2FeSO 4 = 2CuSO 4 + 4FeSO 4 + S The resulting FeSO 4 and S are further oxidized by bacteria to Fe 2 (SO 4 ) 3 and H 2 SO 4 in such a reaction cycle. On the other hand, under the action of bacteria, the copper ore is dissolved by oxygen oxidation. 2Cu 2 S+5O 2 +2H 2 SO 4 =4CuSO 4 +2 H 2 O The leaching of chalcopyrite is believed to be dominated by indirect oxidation of Fe 3+ , which is an indirect oxidant for the leaching reaction. (2) Bacterial leaching of copper blue Since there is no Fe 3+ and other oxidants in the leaching environment, the leaching effect can only be caused by bacteria. The acid consumption is equal to zero during leaching. The reaction is: CuS+2O 2 - CuSO 4 Bacterial leaching was observed throughout the mineral, and the chemical composition indicated by the mineral did not change after leaching, indicating that there was no intermediate process in the leaching that was not converted to other sulfides, nor did the element S occur. (3) Bacterial leaching reaction of sulfur- arsenic copper ore In the presence of H 2 O and O 2 , the direct leaching reaction of sulfur-arsenic copper ore occurs under the action of Thiobacillus ferrooxidans, Thiobacillus thiooxidans and complex bacteria: 4CuAsS+6H 2 O+13O 2 ——4H3AsO 4 +4CuSO 2 (4) Bacterial leaching reaction of chalcopyrite and porphyrite Directly with Fe 2 (SO) 3 in the presence of bacteria. The following reaction occurred CuFeS 2 +2 Fe 2 (SO) 3 - CuSO 4 +2FeSO 4 +2S 2Cu5FeS 2 +2 Fe 2 (SO 4 ) 2 +17O 2 —10 CuSO 2 +4 FeSO 4 +2 FeO Among them, FeSO 4 and FeO are converted into Fe 2 (SO 4 ) 3 under the action of acid and bacteria to carry out a cyclic reaction. (3) Types of copper ore suitable for treatment by hydrometallurgical process For copper oxide ore, as long as the ore particle size is controlled, generally a satisfactory leaching effect can be obtained. However, depending on the type of minerals, copper sulfide ore has a large difference in leaching effect. The copper ore currently treated by biological oxidation in foreign countries is mainly composed of secondary copper sulfide ore (Chalcopyrite, Lanhui copper, copper blue, etc.), while the original copper sulfide ore is still based on fire technology. deal with. In addition, in terms of ore type, the current leaching-extraction-electrowinning technology is mainly applied to porphyry copper ore. This is mainly because the porphyry copper mine is large in scale and contains less alkaline gangue, which is the most ideal raw material for sulfuric acid leaching. Such as the domestic Dexing Copper Mine, Zijinshan Copper Mine, Zhongtiaoshan Copper Mine, Dabaoshan Copper Mine. China's copper resources are characterized by a large number of skarn-type copper deposits, accounting for more than 50%, and reserves account for 29% of total reserves, while Western countries only account for 3%. Such deposits are generally small in scale, scattered and scattered. The storage conditions are more complicated, and most of them are suitable for underground mining, and the mining cost is high. In addition, it contains more alkaline gangue, which is not conducive to leaching with sulfuric acid. Third, the application of hydrometallurgical process in domestic copper mines The production test plants using hydrometallurgical processes in China mainly include Dexing Copper Mine, Zijinshan Copper Mine, Zhongtiaoshan Copper Mine, etc. Now, a brief introduction of its test production, process and technical indicators is given. (1) Recycling process and indicators of copper (waste stone) in Dexing Copper Mine Dexing Copper Mine Heap Leaching Test Plant is based on waste rock (including 0.1% to 25% Cu) stripped by open pit mining. According to the critical grade of 0.25%, the total amount of waste rock is 890 million tons, including copper reaching 951,500 tons. It is difficult to recover copper economically by traditional metallurgical process. With the approval of the State Planning Commission and the Ministry of Science and Technology, a pilot plant with an annual output of 2,000 tons of copper was built in May 1994 and listed as a national “Ninth Five-Year†scientific research project. Because the grade of ore is low and most (more than 85%) are primary sulfide ore, it is the most difficult to dip ore. It is typical in China's copper industry, and its problems and process characteristics are also representative. The test plant produces 1000-2000 tons of copper per year, the original grade copper grade is 0.121%, the leaching rate is 16.59%, and the product quality is grade A. The cost of tons of copper is 10,450 yuan. The mine is the only domestic manufacturer that uses the bacterial leaching process to treat the original copper sulphide ore. Through the heap leaching-extraction-electrowinning process, it not only recovers part of the copper from the stripped waste rock, but also creates certain benefits and reduces waste of resources. And the acid mine water produced by the mining process is no longer efflux, reducing environmental pollution. Since its commissioning in October 1997, the process has been basically stable. The main problem is that the leaching rate of copper in the whole heap is not high, and the concentration of Cu 2+ in the leaching solution needs to be above 1 g/L. However, until now, the concentration of Cu 2+ in the leaching solution has been lower than 0 in the whole production process. .6 g/L. (II) Copper recovery process and indicators of Zijin Mining Company The Zijinshan Mine is a well-known large-scale gold-bearing copper mine. It is characterized by copper deposits on the gold, large reserves and low grade. The copper metal industrial reserves are 1,256,400 tons, the average grade of ore is 0.66%, S 2.58%, and As 0.035%. The main target minerals are mainly blue-copper copper and copper-blue, followed by copper-copper ore, sulphur-arsenic-copper ore and sulfur. Arsenic copper ore. Due to the low grade of raw ore and high arsenic content, the traditional flotation-fire smelting process is adopted, with large investment, high cost and heavy pollution. The Zijinshan copper ore is dominated by secondary copper sulfide, and there is a relatively mature bioleaching process for such minerals. The use of this process to treat Zijin copper ore has good economic benefits. The ore is crushed to -30mm, and the pile-up method is used for automatic unloading. The pile height is 8~10m. The artificially enriched domesticated bacteria liquid is introduced at the initial stage of leaching, and then the acid puddle water of the mining flat is used to match the appropriate amount of industrial sulfuric acid. The leaching agent adjusted to a pH of about 2 was sprayed and leached. At present, it is generally not necessary to separately supplement the bacterial liquid, and it is only necessary to adjust and maintain the pH at about 2. When the Cu2+ concentration in the leachate is greater than 1.5 g/L, it is sent to the extraction electrolysis section to produce cathode copper. At present, a 1000 t/a heap leaching test production plant has been built. The leaching period is 210-240 days, the leaching rate is 70%-75%, the electric copper quality reaches l# copper standard, and the ton copper production cost is 10729 yuan. The company plans to expand the bio-metallurgical plant of 10,000 tons of copper and build the largest biological copper-raising base in China. (III) Copper recovery process and technical indicators of the copper mine in Zhongtiaoshan Copper Mine Copper ore and copper deposits contain a large number of difficult-to-select low-grade copper oxide ore. The proven reserves are more than 18 million tons, the ore grade is 0.65%, and the oxidation rate is greater than 50%. In 1997, Zhongtiaoshan Nonferrous Metals Co., Ltd., Beijing Research Institute of Mining and Metallurgy and Changsha Mining Research Institute cooperated to carry out the “Difficult to Collect and Difficult to Choose Low-grade Oxidized Copper Mine Underground Leaching Industry Testâ€. After nearly 4 years of systematic and comprehensive The experimental research work has formed a complete production technology suitable for the in-situ crushing and leaching of copper in underground mines. At present, there are 2 leaching plants in production and construction, namely the 5# ore body eastern industrialized test leaching plant and the in-situ leaching plant in the subsidence area. 5# ore body in situ crushing test leaching plant The test nugget level is 930-968m, the ore body has an average inclination of 400, a length of 62m and an average thickness of 14m. The geological mineral volume is 33,200 tons, and the grade is 0.975%. The main ore lithology variations and modifications quartz crystal tuff quartz porphyry. The main copper ore mineral malachite, chrysocolla, chalcocite, covellite, the main gangue minerals as quartz, sericite old. Firstly, the ore is crushed to 200mm (>80%) by differential extrusion blasting method, and then the dilute sulfuric acid with a concentration of 1.5%~2% is pumped to the test stop 958 from the liquid mixing station of the pit treatment plant. 968 horizontal cloth channel, and then through the diverter valve, 4m spacing of the fan-shaped cloth liquid hole evenly distributed in the entire stope plane, the dilute sulfuric acid entering the stope penetrates the ore at a certain speed from top to bottom by gravity, with The Cu 2+ in the ore reacts to form a copper sulphate solution, which is collected in the bottom sump of the stope and pumped to the extraction electrolysis workshop to produce cathode copper. The extraction electrolysis process is the same as other production plants. It has been put into production for 2 years and has produced 1000 tons of high-quality electrowinning copper, with a sales income of more than 16 million yuan, a profit and tax of more than 7 million yuan, a unit product cost (excluding tax) of 9,000 yuan / t, a comprehensive recovery rate of 71%, and good economic returns. Fourth, the biological oxidation process on the exploration of ore The biological oxidation leaching process has developed rapidly in foreign countries in recent years. In China, this technology is still in the stage of experimental research and trial production. In principle, this technology can be applied to gold, copper, nickel , lead , zinc , cobalt and other minerals, but at present, it is mainly used in the leaching of two minerals, gold and copper. At present, Yantai Golden Bio-Oxidation Leaching Factory (50t/d), Shaanxi Institute of Geology and Mineral Biological Oxidation Leaching Test Plant (10t/d) and Laizhou Biological Oxidation Leaching Factory (100 t/d) have been built to deal with the difficulty of containing arsenic and sulfur. Gold immersion concentrate powder. Copper hydrometallurgical test plants using bio-oxidation and forming a certain scale of production include Dexing Copper Mine and Zijinshan Copper Mine. The Northwest Non-ferrous Exploration Bureau has also carried out exploratory experiments on this part of the mine exploration ore, but the results are not satisfactory, mainly due to the nature of the ore. Calcium and magnesium ore high consumption of mineral acid, and Leaching is carried out under an acidic pH condition <2. In 1999, the Biological Research Center of Shaanxi Institute of Geology and Mineral Research conducted a bacterial oxidative leaching test on the Jianchaling Flotation Gold Concentrate. The Jianchaling Flotation Gold Concentrate is a low-arsenic and low-sulfur refractory gold concentrate. Gold is present in fine-grained form in sulfide minerals and gangue minerals. Sulfide-coated gold accounts for 44.76%, and silicate-coated gold accounts for 44.76%. 9.26%, carbonate-coated gold accounted for 5.79%, another w(S)=6.22%, W(As)=0.82%. The gold concentrate was directly cyanated, and the gold leaching rate was only 35.3%. After 120 h of bacterial pre-oxidation, the gold leaching rate reached 92.72%. However, due to the high content of alkaline components CaO and MgO in the concentrate, up to 26%, the acid consumption in the oxidation process is high, up to 20%, that is, 200 kg per ton of concentrate, and the treatment cost per ton of concentrate is 240 yuan. In 2002, the Xi'an Jushi Bioleaching Research Center conducted a biooxidation leaching test on the original copper ore in Mujiazhuang, Shaanxi. The same is due to the fact that the gangue minerals in the ore are dominated by iron dolomite, which consumes a high acid consumption and consumes 205 kg of acid per ton of ore. The subsequent bacterial oxidation test was not carried out. According to the relevant information, after the alkaline gangue component in the ore is more than 5%, acid leaching or biological oxidation is difficult, not only the acid consumption is large, but also the reaction of sulfuric acid with calcium oxide to form gypsum , and the cover on the surface of the ore also affects leaching. The Tangdan Mine of Dongchuan Mining Bureau of Yunnan Province used the high-alkaline gangue concentrate obtained by flotation as the object, and the cathode copper was obtained by rotary kiln roasting-pressure ammonia leaching-extraction-electrowinning process, and good results were obtained. However, there is no breakthrough in the research on raw ore. V. Conclusion It is undeniable that the hydrometallurgical process is one of the effective means for large-scale processing of low-grade non-ferrous metals and precious metal ores in the future, and it is also one of the key directions for research and development in many countries in the world. The continuous emergence of new results and the continuous improvement of the process have made it possible for many ore that cannot be processed by existing methods to be fully utilized in the near future. Chevrolet Gas Cap,Chevy Gas Cap,Chevrolet Gas Cap Cover,Chevy Gas Cap Cover GUIDE WIN VEHICLE PARTS CO., LTD. , https://www.guidewinauto.com