Advantages and disadvantages of carbon in leach process
2020-09-16 09:11Introduction：Advantages and disadvantages of carbon in leach process According to the practice of carbon in leachprocess in the past 20 years, compared with the conventional counter-current cyanide dip process, the cyanide carbon in leach process has t
Advantages and disadvantages of carbon in leach process
According to the practice of carbon in leach process in the past 20 years, compared with the conventional counter-current cyanide dip process, the cyanide carbon in leach process has the following advantages:
1. The separation operation of solid and liquid was cancelled: the sieve was used to separate gold loaded carbon and slurry in the carbon in leach process, which simplified the process and saved the expensive solid liquid separation operation. This process is especially suitable for the treatment of raw materials containing gold ore which are difficult to separate from muddy solid-liquid.
2. The cost of capital construction and production is low: because the expensive solid-liquid separation operation is eliminated and the process is simplified, according to statistics, the cost of capital construction can save 25% ~ 50%, and the cost of production can save 5% ~30%. For oxidized argillaceous gold-bearing ores, the savings in capital and production costs are significant. However, for flotation gold concentrate, there is no significant difference between the cost of the carbon in leach process and the reverse current dip process of cyanide agitation.
4. The application scope of cyanide process is enlarged: the gold bearing ore with poor sedimentation and filtration performance is difficult to be treated by conventional cyanidation method. When the content of copper and iron in the leaching solution is high, the efficiency of gold precipitation by zinc replacement process is lower. However, the harmful effects of the above unfavorable factors are relatively small for the carbon in leach process.
5. The amount of cyanide consumption can be reduced: zinc powder replacement process is generally used to precipitate gold in conventional cyanidation, and the solution containing gold should keep a high cyanide content when zinc is replaced by gold. Electrolytic precipitation of gold is usually obtained by desorption of gold by charring process, and the content of cyanide in the solution is not required. Therefore, the lower concentration of cyanide in the carbon in leach process is beneficial to reduce the consumption of cyanide.
6. High purity gold ingots can be produced : The carbon in leach process use electrolytic deposition oprocess to extracr gold. The purity of gold slime is high, the flux consumption and melting time can be reduced, the loss of gold in slag and flue gas is small, and the gold ingot with high purity can be obtained.
There are also some shortcomings in the process of carbon in leach, such as the following three points: ⑴the slurry that enters the adsorption circuit of the propeller needs to be sifted (screen mesh generally 0.589 mm), cyanide leaching and carbon adsorption are carried out in different circuits, and the capital construction cost is still high; (2) the retention of gold and silver is large in the process of carbon in leach process, a large amount of gold loaded carbon is stuck in the adsorption loop, and there is a serious backlog of funds ;⑶The problem of the wear and tear of activated carbon is still not solved thoroughly, although many effective measures have been taken. However, some of the worn fine particles of gold-loaded carbon are still lost in tailings, which reduces the recovery of gold. In order to simplify the process and reduce the wear of activated carbon, it is necessary to further improve the process and develop more efficient equipment in the future.
