Design of rich liquid pool for heap leaching
heap leaching began in 1752, and it was first used to treat copper oxide in Spain. At the end of 1950s, heap leaching was successfully used to treat low-grade uranium ore. The US Bureau of mine was first used in instry to extract gold in 1967
heap leaching has the advantages of simple process, less capital investment and low operation and management costs. It can treat the so-called non instrial ores such as lean ores with gold content of 1-2g / TT, including stripping gangue, ancient tailings abandoned by gold extraction enterprises, low-grade oxidized ores, etc
e to the rising price of gold, heap leaching has developed rapidly. A large number of experiments and researches on heap leaching have been carried out in the main gold procing countries in the world, and then it has been used in large-scale proction. For example, the gold proced by heap leaching in the United States in 1989 accounted for about 20% - 30% of the total output of the country
the heap leaching method is similar to the percolation method, but the workplace is different. The leaching operation of the latter is carried out in the infiltration tank, while the former is carried out on the site where the gold bearing ore is placed on the special non permeable cushion (as shown in the figure)
heap leaching is usually carried out in the open air, and the heap leaching site is generally located near the flat and convenient mining area. The construction of the site and the selection of cushion materials are the key technologies of heap leaching operation. A little leakage of the cushion will cause the loss of gold bearing solution and rece the yield of gold
in order to ensure that the site is easy to operate and free from leakage, it is necessary to level the site first, and make 2 ～ 4 And then compaction. The cushion layer shall be laid on the flat and compacted site. The cushion can be tamped with reinforced concrete, asphalt or clay. It can also be made of plastic or rubber sheet
the ore is piled up on the site with cushion. Heap building method has a great influence on heap leaching effect. A good ore heap should meet the following requirements: the ore particle size is evenly distributed on the random cross section of the ore heap, there will be no particle size segregation, so that the ore maintains a certain degree of looseness; The looseness is relatively homogeneous; Cyanide solution can penetrate into the ore well and evenly without channeling
usually, loaders, bulldozers and other machinery are used to build piles. The shape of the pile is mostly square truncated cone. The height of ore heap is 3-15m. Some people think that if the stack height exceeds 6m, the yield of gold will decrease. The capacity of ore heap is 100000-200000 tons or more
heap leaching is suitable for the treatment of porous ores in which gold mainly occurs in mineral fissures. The particle size of the ore should be 5-20 mm, and the ore of about 100 mm can also be treated. If the particle size of ore is fine or there is a large amount of argillaceous material in it, a small amount of cement, alkali and cyanide can be added to granulate first and then leach to improve the leaching effect of gold
cyanide solution, sprayed on the ore heap with special sprayer installed on the ore heap. The spraying speed of cyanide solution is related to the properties of ore and stacking method. Usually 0.15-3 m is injected into the surface area of ore heap per square meter every day and night. Solution. Cyanide leaching agent generally contains 0.05% ～ 0.1% NaCN, and its pH is 10 ～ 11. It is better to use caustic soda to protect alkali, because lime milk easily blocks the sprayer.
the cyanide solution sprayed on the ore heap seeps through the ore heap and flows from the cushion into the chute arranged longitudinally along the ore heap, lined with plastic or rubber, and discharging precious liquid. Then it flows into the ground trough, the precious liquid pool. The precious liquid proced by heap leaching is usually extracted with carbon slurry method to recover gold and silver. The lean solution after gold removal is added with appropriate amount of alkali and sodium cyanide and returned to the next leaching process
after washing and leaching, the ore heap is washed with water spray to wash the dissolved gold from the ore heap and ore. Add appropriate amount of sodium cyanide and alkali into the washing water and return to the next leaching together with the lean solution. The amount of washing water should be able to compensate the evaporation or other loss of the solution, so as to maintain the balance of the solution. The washed tailings are transported to the tailings yard
heap leaching has a long period of gold extraction, low extraction rate of gold and silver, and generally takes about 30-90 days and nights from heap building, leaching, water washing to tailings discharge. The leaching rate of gold and silver is usually less than 50% - 70%.
1. The method of extracting copper from mixed copper deposits (invention patent)
copper sulfide and copper oxide are crushed and processed to obtain high purity cathode copper. The combined process has the advantages of high recovery rate, low cost, less investment and no pollution. It can bring new development to the metallurgical instry in areas with this kind of mixed copper resources
2. Continuous preparation method of pure gold sol (invention patent)
the invention is a continuous preparation method of pure gold sol by laser bombardment of solid-liquid interface. The method of the invention can continuously prepare pure gold sol without harmful impurities such as excessive recing agent and its reaction by-procts, protective agent, dispersant, etc., without purification. As an additive, it can be directly applied to microelectronic devices, ultra large scale integrated chips, medicine, immune labeling, food, beverage, drinking water, liquor, cosmetics and other instries
3. The enclosed electrolyzer (patent specification of utility model)
the device can isolate the acid harmful gas proced by the electrolyzer in the process of hydrometallurgy proction and lead it away by the exhaust pipe, so as to improve the working environment of operators and rece the hazards of occupational diseases. The closed electrolyzer is simple in structure and convenient in operation, which is suitable for application in hydrometallurgical electrowinning process
4. Self flow static adsorption method in heap leaching (invention patent)
the invention is a self flow static adsorption method for heap leaching of gold ore. The open type non flow fixed bed adsorption tank is adopted. By selecting the favorable terrain of the mine, multiple adsorption tanks are arranged in series in a stepped manner. According to different rich liquid grade and flow rate, the appropriate carbon layer height and adsorption time are selected to obtain the ideal adsorption rate. The whole adsorption process is static self flow, no power consumption and activated carbon wear, low labor intensity
5. Self tightening lifting hook for large ore (patent specification of utility model)
the lifting hook is composed of three claws, positioning ring, tension rope and other components, and its shape is similar to that of household cooking hook. When in use, the three claws hook the ore, and the tension rope has self tightening effect. The heavier the ore is, the greater the self tightening force is. It has the advantages of convenience, safety and high efficiency, and is the best way to replace the steel rope binding lifting< The invention is a beneficiation method which can effectively improve the recovery rate of low-grade oxidized gold ore with high mud content and coarse-grained bright gold. The method combines three processes of heap leaching, gravity separation and carbon leaching, overcomes the disadvantages of high mud content affecting the heap leaching permeability, and shortens the heap leaching cycle, Compared with the single heap leaching process, the recovery of mineral processing is significantly improved, reaching more than 80%, and the precious resources are fully utilized
7. Closed type pretreatment device for fine disseminated gold ore (utility model patent)
the device is a closed type pretreatment device for fine disseminated gold ore, which has the characteristics of high recovery rate, low investment, low cost, friendly to environment, low labor intensity, etc., and is suitable for refractory gold ore, low cost, low cost, low cost and so on Large scale instrial proction of recovering precious metals and nonferrous metals from gold concentrate and complex nonferrous metal ore
8. Open type non fluidization fixed bed adsorption device (utility model patent)
the open type non fluidization fixed bed adsorption device is suitable for heap leaching gold extraction process or all slime cyanidation countercurrent washing activated carbon adsorption process in gold instry, and is the key equipment of adsorption system. The device has the advantages of high adsorption rate (≥ 98%), no abrasion of activated carbon, convenient operation, large operation flexibility (1 ~ 200m3 / h) and no power consumption in the adsorption process. It is the best device to replace the traditional adsorption tower (column)
9. Technology of leaching copper from copper sulfide by using bacteria bearing copper mine acid pit water (invention patent)
the invention is a new technology of leaching copper sulfide by using bacteria bearing copper mine acid pit water. The process can make full use of mineral resources, improve the recovery level of copper, save costs, improve profits, and improve proct quality. At the same time, the acid mine water in the mine can be turned into treasure, rece the cost of environmental protection treatment, and rece the pressure of environmental protection
