The principle flow and working way of agitated cyanide leach
2020-08-31 09:57Introduction：The principle flow and working way of agitated cyanide leaching in Gold Mine Agitated cyanide leaching is generally suitable for gold bearing materials with grinding particle size less than 0.3 mm. The principle flow is shown in Fig. 5-15.
The principle flow and working way of agitated cyanide leaching in Gold Mine
Agitated cyanide leaching is generally suitable for gold bearing materials with grinding particle size less than 0.3 mm. The principle flow is shown in Fig. 5-15. Compared with percolation cyanide leaching process, agitated cyanide leaching has the characteristics of small workshop area, short leaching time, high degree of mechanization, high gold leaching rate and strong adaptability of raw materials.
In order to improve the recovery rate of gold and shorten the leaching time of cyanide, mercury mixing process , gravity separation process or flotation process are often used to recover coarse gold before cyanide leaching, and a large number of gangue and harmful impurities are removed by gravity separation or flotation to obtain gold concentrate. Gold concentrate is often reground for cyanide leaching. When the gold ore contains a large amount of clay, ochre, shale and particulate gold, the flotation index is lower. The gold ore can be ground in the gold removal solution (barren solution), then the gold can be extracted by cyanidation of the row ore. Therefore, the gold-bearing materials extracted by agitated cyanide leaching can be raw ore, mercury mixing tailings or gravity separation tailings, flotation gold concentrate, gold-copper mixed concentrate after flotation separation of gold-bearing pyrite concentrate and gold-pyrite cinder, etc.
Agitated cyanide leaching can be divided into continuous agitated cyanide leaching and intermittent agitated cyanide leaching according to its operation mode. During continuous agitation leaching, the slurry can be leached downstream by several agitators in series, and pump can be used when the slurry can not be self-flowing. In general, the slurry should be self-flowing, as far as possible to reduce the frequency of pump lifting, in order to reduce power consumption. During intermittent agitation leaching, the pulp is fed into several parallel stirred leaching grooves. At the end of leaching, the slurry is discharged into the storage tank, and another batch of slurry is fed into the agitating leaching tank for leaching.
Continuous agitation cyanide leaching is often used in gold separation plants. Discontinuous agitating cyanide leaching is used only in some small separation plants or when some refractory gold ores are treated and new cyanide solution is used for each stage of leaching.
Continuous agitation cyanide leaching is usually carried out in three to six agitated leaching grooves in series, and the leaching tanks are usually installed step by step, and the slurry can pass through each leaching tank in a balanced and continuous manner. The time of slurry passing through each leaching tank should be equal to or slightly larger than the leaching time required under the leaching condition. Compared with the discontinuous process, the continuous agitation leaching process can shorten the loading and unloading time, the equipment has a large processing capacity, the leaching slurry can be continuously sent to separate the solid and liquid, the storage tank can be saved, the area of the workshop and the power consumption can be reduced, and the process is continuous. It helps to automate the process and improve working conditions. This operation can be used in most gold-dressing plants.
Intermittent agitation leaching is commonly used in gold processing plants with less than 100 tons per day, and several or even a dozen leaching tanks are often used in parallel operation for large scale separation plants. After leaching, the slurry is fed into the tank and separated by solid and liquid in batches. The slurry in the tank must be continuously stirred to prevent the settling of the ore particles.
The ratio of liquid to solid is usually 1: 1 when leaching by agigating cyanide. Leaching in the same leaching tank, washing, at the end of leaching ,we can add washing water to dilute slurry to liquid to solid ratio of 3: 1.
