1. Technical characteristics of gold concentrate cyanide gold extraction
Gold cyanide extraction technology is the modern major gold-producing means, China was in the early 20th century had to extract gold Using this method, first built in 1901 2t / d pilot plant in Shandong Weihai Fan cyanide home port, after 1932 In Zhaoyuan and Weinan, Shandong, in 1936, the dialysis and stirring cyanide technology were tested in Jinguashi, Taiwan. In 1966, the Linglong Gold Mine in Shandong Province was built into a gold-smelting machine for continuous mixing of cyanide gold-plating plants. In 1970, it was applied in Jinchang, Hebei, and in 1977 in Liaoning Wulong Gold Mine. The cyanide carbon slurry gold extraction technology was successfully researched in the early 1980s, and the Changchun Gold Research Institute established 50t/ of China's intellectual property rights in two gold mines in Chiweigou, Jilin Province, in Linghu, Jilin Province and Jilin Metallurgical Research Institute. d Production scale of carbon slurry plant, and then introduced technology and equipment from abroad in the mid-1980s in Shaoguan, Shaanxi, Zhangjiakou, Hebei, built a full mud cyanide carbon pulp plant, China's cyanide gold extraction technology has been a long-term development, a variety of processes Diversified, the technology is improving day by day, the indicators are gradually improved, and the application is more extensive. In the 1990s, a resin slurry gold extraction plant was built in Xinjiang Axi and other gold mines. Cyanide gold extraction technology has become the main force of China's gold industry production. Since the gold concentrate cyanide process has been successfully tested in the 1960s, it has been used in many gold mines, especially in Shandong, Hebei, Henan, Liaoning, and Jilin. The main feature of the process is that after the gold ore is enriched by flotation, the gold content of the concentrate is high, the amount of gold entering the cyanide operation is small, the consumption of cyanide is low, and the acidification method has a good effect on the treatment of cyanide-containing wastewater, and environmental pollution. Small, can save infrastructure investment, small footprint, reduce production costs, and can achieve real estate gold.
Gold concentrate cyanide gold extraction process For the primary minerals with relatively simple mineral composition, the general flotation recovery rate is high, usually between 93% and 98%, and the cyanidation recovery rate is about 95%. Therefore, flotation - - The total recovery of cyanidation is 88% to 94%, which is equivalent to the whole mud cyanidation technology.
However, in terms of total mud cyanidation, concentrate cyanide has less capital investment, less cyanide-containing wastewater, and lower production costs. This is the main reason why this process is widely used.
Second, gold concentrate cyanide gold extraction process classification
On the status and the type of rock gold mining deposits in the domestic mine production using this technology point of view, flotation - concentrate typical of cyanidation process is mainly used for simple gold minerals gold-bearing quartz vein type gold-bearing sulfide ores and erosion Variable rock type ore. These two types of ore represent the vast majority of the gold industry. The typical representatives are the Linglong and Xincheng gold mines. The chemical element composition of the gold concentrate is shown in Table 1 and Table 2, respectively.
Table 1 Chemical element content of flotation concentrate in Linglong gold mine
element | Au(g/t) | Ag(g/t) | Cu | Pb | Zn |
content(%) | 90.0 | 53.0 | 0.83 | 0.29 | 0.31 |
element | Fe | S | As | P | Hg |
content(%) | 27.80 | 31.60 | 0.02 | 0.03 | <0.001 |
Table 2 Multi-element analysis results of cyanide ore from Xincheng Gold Mine
element | Au(g/t) | Ag(g/t) | Cu | Pb | Zn | S | Fe |
content(%) | 82.50 | 121.0 | 0.37 | 0.90 | 0.21 | 43.72 | 43.15 |
Some flotation gold concentrate containing high copper mine, or (as Inner clear water, Guangdong Gaoyao Hetai Gold, etc.), or with a higher silver (such as Zhejiang Suichang gold), or with a high lead ( For example, the Sanshandao Gold Mine in Shandong Province, although the cyanidation technology used in it is also a conventional cyanidation, it is necessary to adopt some special techniques or add some kind of passivating agent to make the process smooth and the index improved.
Also. Xiaoqinling area of gold mines such as Henan WENYU Qinling, Dongchuang like gold, containing multi-metal mining quartz vein-type deposits, gold, silver flotation concentrate rich in sulfur and other elements Fe Zn Pb, difficult to directly cyanide, The copper and lead must be recovered after calcination to remove copper and then cyanide to extract gold and silver.
However, with social development and technological progress, the number of hundreds of tons of metal content of arsenic deposits, with the diversification and pre-engineering technology, but also production of gold flotation concentrate, since the late 1990s have After the birth of the bacterial oxidation of intellectual property in China - the cyanide carbon slurry process gold demonstration plant, this kind of gold concentrate has become a sought-after raw material. Data 2 describes the classification of pretreatment methods for refractory gold ore and gold concentrates. See Table 3.
Table 3 Refractory gold ore and gold concentrate pretreatment method
Pretreatment method | Scope of application |
Bake and enrich Calcination oxidation Pressurized oxidation Biological oxidation Carbon immersion Ultrafine grinding | Gold concentrate Sulfide-coated gold or carbon gold ore, gold concentrate Sulfide, antimony compounds wrapped gold ore, gold ore, this method can not be oxidized ores organic carbon The raw ore and gold concentrate of sulphide-coated gold can be stirred or heap leached. Can overcome medium carbon gold Finely wrapped gold ore and gold concentrate |
Third, conventional cyanidation
The conventional cyanidation process of gold concentrates in China has undergone a long process of experimentation and exploration. In the mid-1960s, when the Zhaoyuan Linglong Gold Mine was completed and the gold concentrate machinery was continuously stirred, the cyanide gold extraction plant was used. The gold leaching rate was 3% to 5 times lower than the typical two-dip two-wash method currently used. %, the concentrate leaching tank is used after a slight modification on the mine agitation tank, and an inflation tube is inserted around the tank. The stirring method has high energy consumption, is easy to sink, has poor air dispersion, and has low leaching efficiency. At that time, the use of a dip-wash process could produce the quality of gold in situ, greatly reducing the loss of concentrate transportation, shortening the capital turnover and improving the business operation. Since the flotation operation contains metals such as copper and zinc, especially when the oxide content is high, a large amount of cyanide is consumed during the cyanide leaching process, and the concentration of copper and zinc complex in the solution is too high, which hinders the cyanide of gold and silver. Dissolved. After years of experimental research and production summary, it was changed to two-dip two-wash in the late 1970s; the original low-efficiency zinc wire replacement was changed to zinc powder replacement; the sodium cyanide and heavy metals in the tail liquid were recovered by acidification. The process improves the recovery rate of gold and reduces the consumption of cyanide. Therefore, a typical gold extraction process for gold concentrate is formed. The process flow is shown in Figure 1.
Before the gold concentrate enters the cyanidation operation, it needs to be re-grinded, de-druged and alkali-treated, and then subjected to secondary leaching and secondary washing. After washing, the precious gold contained in the gold is replaced by zinc powder to obtain gold mud, and the gold mud is sent to the gold smelting room. And sell the quality of the gold. After the replacement, the lean liquid is treated by acidification to recover the cyanide and then returned to the leaching operation. Most of the acidified sludge is returned to the washing operation, and a small part is treated and discharged to the tailings storage. Its main equipments include: one MQY1530 ball mill and one NX18 m pre-dip concentrator. Leaching agitating tank 3.0×3.5 m 10 sets, two dips 4.0×4.5m 4 sets, three-layer thickener 9m 4 sets, deoxygenation tower 3 sets of 1.5m, 2 sets of plate filter, 1 set of zinc powder feeder and 40m 2 of replacement filter press. The data of 10 leaching tanks are shown in Table 4.
Table 4 leaching tank inspection data
Leaching tank Numbering | Liquid | Slag Gold (g/t) | Single slot Leach rate (%) | Grand total Leach rate (%) | ||
Au (g/m 3 ) | Cu 2+ (mg/L) | CNS - (mg/L) | ||||
1 2 3 4 5 6 7 8 9 10 | 14.46 15.11 16.03 18.16 18.70 19.36 2.95 2.98 3.00 3.06 | 305 385 422 456 502 504 107 117 138 148 | 391 568 653 741 848 939 297 373 438 450 | 16.49 15.17 13.38 8.98 7.88 6.544 1.10 1.033 1.029 0.992 | 64.03 8.00 12.33 32.48 12.25 16.95 83.19 6.06 0.39 3.60 | 64.03 66.91 70.99 80.41 82.81 85.72 97.60 97.75 97.76 97.84 |
The main features of the process: (1) Two-dip two-washing solves the problem of low cyanide recovery rate and high cyanide consumption of copper-containing gold concentrate; (2) Cyanide content of poor liquid after replacement is 2100-2300 mg/L, acidification The method can recover 70% of the solution and recover heavy metal to recover copper thiocyanate; (3) use lime alkaline pretreatment before leaching to form a passivation film on the surface of metal oxide such as copper and zinc. It is not dissolved in the cyanide solution; (4) The introduction of the foreign double-impeller hollow shaft inflatable leaching tank reduces the power of the mixer from 17kW to 7.5kW, which not only saves energy, but also has significant leaching effect.
This method has become a typical example of the cyanide gold extraction process of gold concentrate in China. The copper content of cyanide can be reduced to less than 1%, and the consumption of cyanide by copper is reduced by only a single alkali treatment. Good technical and economic indicators are shown in Tables 5 and 6, respectively. The process is used in most mines in Shandong, as well as gold mines in Hebei Jinchang, Liaoning Wulong and Jilin Jiapigou.
Table 5 Technical indicators of industrial production of Zhaoyuan Linglong Gold Mine
Numbering | Cyanogen Gold (g/t) | Cyanide residue Gold (g/t) | Precious liquid Gold (g/m 3 ) | Lean liquid Gold (g/m 3 ) | Drainage Gold (g/m 3 ) | Leaching rate (%) | washing rate (%) | Replacement rate (%) | Total cyanide Recovery rate (%) |
1 2 | 53.76 51.94 | 1.38 1.21 | 9.03 10.26 | 0.01 0.02 | 0.07 0.12 | 97.43 97.67 | 99.85 99.70 | 99.73 99.88 | 97.02 97.27 |
Table 6 Economic indicators of industrial production of Zhaoyuan Linglong Gold Mine
Numbering | Sodium cyanide consumption (kg/t) | Zinc powder (kg/t) | Coagulant (kg/t) | Power consumption (kwh/t) | Cyanide cost (yuan/t) | Sewage treatment cost (yuan/m 3 ) | ||
New consumption | Recycling | Total consumption | ||||||
1 2 | 5.39 4.95 | 2.80 2.47 | 8.16 7.42 | 0.24 0.22 | - 0.43 | 64.0 55.60 | 32.69 32.51 | 2.73 2.54 |
4. High-silver and copper-bearing gold concentrate cyanidation technology
Suichang gold mining sulfide-depleted quartz vein gold, the gold content of the ore 9.7g / t, silver content of up to 242.96g / t, the mineral composition is more complex, but still are easy dressing stone, fine particles of gold to the majority . Mainly in the gold and silver mines and silver and gold mines, fine grinding is required to dissociate the gold and silver mineral monomers. Since the completion of the 300t/d mining scale in 1986, the gold concentrate was sold to the Fuchunjiang smelter in the past by a single flotation process. In order to realize the real estate gold, reduce the loss of concentrate transportation, accelerate the turnover of funds, and improve the efficiency of enterprises, in 1989, the cyanide workshop was built and put into production. The chemical composition of the gold concentrate is shown in Table 7.
Table 7 Chemical composition of gold ore deposits in Suichang Gold Mine, Zhejiang Province
element | Au(g/t) | Ag(g/t) | Cu | Pb | Zn | Fe |
content(%) | 98.72 | 2984.77 | 0.37 | 0.61 | 2.005 | 30.27 |
element | S | Mn | SiO 2 | Al 2 O 3 | CaO | MgO |
content(%) | 33.37 | 0.33 | 23.85 | 6.89 | 0.476 | 0.182 |
The mine was specially tested before the plant was built, but the results were unexpected. It is well known that the recovery rate of silver by cyanidation is generally not high, and the recovery rate of silver in this test is as high as 95.15%. Secondly, the size of concentrate concentrate reaches -320 mesh, accounting for 77.60%, the highest gold leaching rate, and the over-grinding decreases. Dissolved in the cyanide solution to form a silver cyanide complex, which must be maintained at a high concentration, the cyanide concentration is maintained at about 0.08%, and the cyanide consumption is as high as 8.1 kg/t.
On the basis of experimental research, the process of two-dip two-wash, zinc powder replacement, acidification sewage treatment and gold mud fire smelting process was completed. After years of production practice, the recovery rate of gold and silver cyanide reached 97.15% and 90.26% respectively. Get great results. Its main features are: (1) high concentration cyanide leaching plus moderate grinding, that is, a 320 mesh accounted for about 75%, a cyanide concentration in a dip operation is controlled between 0.08% and 0.10%, and a dip operation is controlled at 0.06%. -0.08% up and down; (2) using an automatic vertical filter press to filter the dross, the cyanide tailings are sulfur concentrates, 30% to 35% of sulfur is sold to the chemical plant near the acid; (3) the mine Located in Jiangnan Water Town, the population is dense and the water system is developed. If ordinary cylindrical filter is used, the water content of the filter cake will be as high as 20%, and the sulfur concentrate needs to pass through several villages. If the car is not tightly sealed, it will be scattered, which will cause serious pollution to the environment. However, the water content of the filter cake will be reduced to 8% to 10% after using the automatic vertical filter press. It is in the state of dry cake and meets environmental protection requirements.
Generally considered. It is uneconomical to adopt a cyanidation process when the gold content of the gold concentrate is greater than 1%. The main reason is that copper minerals consume a large amount of cyanide. Thereby affecting the leaching rate of gold; at the same time, copper is not effectively recovered due to the large amount of cyanide dissolved during the leaching process. The information on the solubility of copper minerals in sodium cyanide solution is shown in Table 8. however. Guangdong Gaoyao Hetai Gold Mine has solved this problem well in Jinjing. The ore deposits gold-altered mylonite deposits. The solubility of copper minerals in the 0.099% NaCN solution is 0.2% to 0.3% in the ore. Gold ore was obtained after ore flotation, and was sold to the smelter before 1998. Due to smelter pressure, pressure grade and delay in returning goods and long-distance transportation and loss. The business situation of the company has been passive. In order to change this aspect and realize the technical transformation of the gold concentrate cyanide project in 1998, the multi-element analysis of copper-bearing concentrates is shown in Table 9. The relative content of copper oxide is only 9.01%, and the rest is sulfide. It is pretreated with alkali in the conventional cyanide leaching test. The cyanide consumption is still l2kg/t. The gold leaching rate is 96%, which is ideal. In order to reduce the consumption of cyanide. The engineering and technical personnel of the mine made in-depth exploration and research. After years of efforts, a special method was adopted to reduce the consumption of sodium cyanide to 8kg/t. Information 6 is introduced.
Table 8 Solubility of copper minerals in 0.099% NaCN solution
Mineral name | Molecular formula | Copper dissolution rate (%) | |
23°C | 45 ° C | ||
Metal copper Azurite Copper mine Chrysocolla Copper ore Chalcopyrite Copper ore malachite Sulfur arsenic copper ore Beryllium copper mine | Cu 2CuCO 3 ·Cu(OH) 2 Cu 2 O CuSiO 3 Cu 2 S CuFeS FeS·2Cu 2 S·CuS CuCO 3 ·Cu(OH) 2 3CuS·As 2 S 5 4Cu 2 S·SB 2 S 3 | 90.0 94.5 85.5 11.8 90.2 5.6 70.0 90.2 65.8 21.9 | 100.0 100.0 100.0 15.7 100.0 8.2 100.0 100.0 75.1 13.7 |
Table 9 Multi-element analysis results of gold concentrate in Hetai Gold Mine
element | Au(g/t) | Ag(g/t) | Cu | Pb | Zn | Fe | S |
content(%) | 96.0 | 34.0 | 4.7 | 0.038 | 0.10 | 20.21 | 14.08 |
element | Ni | MgO | Al 2 O 3 | CaO | SiO | CaO | C |
content(%) | 0.049 | 0.02 | 0.89 | 8.95 | 44.92 | 0.66 | 0.34 |
In order to continue to reduce the cyanide consumption and make modifications, the original cyanidation process is carried out to increase the leaching time by edge grinding. The cyanide lean liquid is returned to the regrind operation, and the grade of the leaching tailings is high. The following measures are taken during the transformation: one cancels the edge grinding process, the lean liquid does not return to the regrind operation, and returns to the leaching slurry; Before adding lime, the pulp is controlled to pH=9; the third is to increase the regrind fineness, so that 400 mesh accounts for more than 90%, and the second dipping and second washing process is still adopted, and the consumption of sodium cyanide is reduced from 8.01 kg/t to 4.59. Normal level of kg/t. The gold leaching rate increased by 1.27%. Up to 98.43%. The gold concentrate cyanidation process is a new way for such gold mines.
However, the treatment method of copper-bearing gold concentrate is divided according to the amount of copper. The basic rule is that the higher the copper content, the lower the gold leaching rate, the conventional cyanidation allows the copper content to be below 1%; the copper content is between 1% and 6%. It is necessary to adopt special methods to reach the conventional indicators; when the copper content is greater than 6%, such as the small southwestern area of ​​Changbai Mountain, the Hunchun gold and copper mine, and the gold mines such as Jiguanzui, Jilongshan and Taohuazui in the middle and lower reaches of the Yangtze River, the copper The grade is high and the gold concentrate is sold to the smelter. Among them, the original ore grade gold of Jiguanzui Gold Mine is 2.74 g/t, copper is 1.595%, iron is 40.82%, and sulfur is 6.53%. Also associated with Ag, Mo, Se, Ni and other elements. However, Data 7 introduces the cyanide leaching test of gold concentrate in Hunchun Gold and Copper Mine. The copper grade is 12.5%, and the gold leaching rate is only 43.64% during conventional cyanidation. However, after the drug is removed, the ammonia leaching solution is used to increase the gold leaching rate to 93.43%. Whether or not to build a factory is unknown.
Five, roasting enrichment method
The gold-bearing polymetallic sulphide quartz vein gold deposit is mined in the Xiaoqinling area of ​​Shaanxi, Henan Province, and the mixed concentrate is generally produced. Its grade gold is 98.89g/t, silver 150g/t, copper 1.45%, lead 2.5%, zinc 1.2%, sulfur 26%, iron 31%. For this complex gold concentrate, the former National Gold Bureau built the Zhongyuan Smelter in Sanmenxia City, specializing in the smelting of gold concentrate produced in the gold mines of Henan and Shaanxi. The processing capacity is 250t/d, and comprehensive recovery of gold, silver, copper, lead and sulfur It was completed and put into production in 1991.
The gold concentrate is subjected to sulphation roasting in a vertical boiling furnace, and the flue gas enters the sulphuric acid system. The calcination was leached for 1 h at a temperature of 70 ° C, a slurry concentration of 40%, and a sulfuric acid content of 15 g / L. The liquid containing copper was 13.19 g/L by liquid-solid separation, and the sponge copper containing 75% of copper was directly sold by using iron. After the copper was immersed in the slurry to a liquid-solid ratio of 2.9, salt and hydrochloric acid were added, and the pH was immersed at 50 ° C for 5 h. The leaching solution obtained by solid-liquid separation contained 9.51 g/L of lead and 34.2 mg/L of silver. Iron 12.72%. After heating to 90 ° C, it was replaced with iron powder to obtain a silver sponge lead. The leaching residue after the lead removal was again adjusted to a liquid-solid ratio of 2.9. The leaching time was 36h under the condition of sodium cyanide concentration of 0.08% and pH=10.5～11. After solid-liquid separation, the gold was replaced by zinc powder. The gold leaching rate was 98.17% and the copper recovery rate was 84.15%. The lead recovery rate was 89.10%.
The Hunan Xiangxi gold deposit is a gold-bearing tungsten-polymetallic quartz vein or quartz vein vein deposit. Two concentrates, namely tungsten concentrate and gold-bearing concentrate, are separated separately in production. The mine has built a smelting workshop to treat the two concentrates separately. The niobium-containing concentrate contains the following three steps to achieve the separation of sheet metal: one is high temperature roasting, the other is electrolysis separation, the third is secondary oxidation, and the separation and smelting of fine and high quality gold are sold.
6. Pretreatment oxidation gold extraction process
Information 8 describes the current status of the treatment technology of difficult metallurgical ore in China. These are difficult to recover gold ore or gold concentrate using conventional cyanidation. Most of them contain harmful elements such as arsenic carbon, and must undergo various pretreatment processes to recover gold by cyanidation or other methods. 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. The production capacity of 100t/d gold concentrate is 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.
Information 9 describes 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.
Data 10 introduces a gold ore, gold, lead, zinc, sulfur and other multi-metal associated low-temperature hydrothermal sulfide deposits in a gold mine. The oxidation degree is high, the mud content is large, the copper sulfur and arsenic content is high, the gold particles are fine, and it is difficult to handle gold. Multi-metal ore, built with 70t / d flotation plant, producing 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.
Conclusion
(1) China's cyanide gold extraction technology began to be applied earlier, but the wide-ranging application was in the 1970s and 1980s, and the gold concentrate cyanide gold extraction was first used in industrial production.
(2) In the late 1980s and early 1990s, there were more than 100 carbon pulp plants in China, but most of the mines, especially the small and medium-sized quartz vein deposits, still produce gold concentrates by flotation. Mainly, in order to adapt to this process, various places have built gold concentrate cyanide gold extraction plants, such as Shandong Zhaoyuan, Laizhou, Liaoning Chaoyang, Henan Lingbao, etc. to smelt local production of gold concentrate.
(3) The conventional process of cyanidation of gold concentrate is the industrial production process of two-dip two-washing, replacement of noble liquid zinc powder, tail acid acidification method to recover cyanide and heavy metal, and gold mud smelting.
(4) The process of cyanide recovery of copper-containing lead and high-silver gold concentrate requires some special methods to achieve the desired index. If the copper content is higher than 6%, it must be sold to the smelter.
(5) Flotation gold concentrate containing gold polymetallic sulfide quartz vein type is generally sold to a smelting plant, which uses sulfuric acid roasting, acid leaching and salt leaching to recover valuable metal copper and lead, and then cyanide gold.
(6) Gold-containing arsenic gold concentrate recovery technology. After the “Ninth Five-Year†scientific and technological research, there have been industrial production plants (workshops) that can directly produce gold by roasting, hot pressing and bacterial pre-oxidation, and then for several years. This type of gold concentrate is no longer a difficult category.
(7) Some gold concentrates containing arsenic and carbon have also been successfully pretreated, providing complete sets of technology and equipment for small and medium mines.
(8) The technology, process and equipment for cyanidation and gold extraction of gold refractory gold concentrates in foreign countries are better than those in China. We should absorb foreign advanced technology and equipment to provide a broad platform for the development of China's gold industry after researching process equipment with independent intellectual property rights. .Lunch Box,Environment Lunch Box,Wheat Straw Lunch Box,Environment Wheat Straw Lunch Box
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