According to the practice of carbon slurry process for decades, compared with the conventional stirred cyanidation countercurrent decantation process, the cyanidation carbon slurry process has the following advantages.
.jpg "Advantages of Carbon in Pulp Process (CIP)")
The carbon slurry process uses sieves to separate gold loaded carbon and pulp, simplifying the process and eliminating expensive solid-liquid separation operations. This process is especially suitable for the treatment of argillaceous gold bearing mineral raw materials that are difficult to separate solid and liquid.
Due to the elimination of expensive solid-liquid separation operations and the simplification of the process, according to statistics, the capital construction cost can be saved by 25% - 50%, and the production cost can be saved by 5% - 30%. For oxidized argillaceous gold bearing ores, the savings in capital construction and production costs are quite obvious. However, for flotation gold concentrate, the cost difference between carbon slurry process and stirred cyanide countercurrent decantation process is not obvious.
The general gold content in the lean solution of conventional zinc cyanide replacement gold precipitation is 0.03g/m3, and the liquid phase gold content in the residual pulp discharged from the carbon pulp process is generally 0.01g/m3. Therefore, the gold recovery rate of carbon slurry process is higher than that of conventional cyanidation.
Generally, gold bearing ores with poor sedimentation and filtration performance are difficult to be treated by conventional cyanidation. When the content of copper and iron in the gold containing precious liquid obtained by leaching is high, the efficiency of gold precipitation by zinc replacement method is low. However, for the carbon slurry process, the harmful effects of the above adverse factors are small.
Conventional cyanidation generally uses zinc powder replacement method to precipitate gold. When zinc replacement is used to precipitate gold, the gold containing solution should maintain a high cyanide content. The precious liquid obtained by desorption of gold loaded carbon in carbon slurry process is usually used for gold precipitation by electrolysis, and there is no requirement for the content of cyanide in your liquid. Therefore, the cyanide concentration in the carbon slurry process is low, which is conducive to reducing the consumption of cyanide.
The carbon slurry process uses the electrolytic deposition method to extract gold. The purity of gold mud is high, which can reduce the flux consumption and shorten the smelting time. The loss of gold in slag and flue gas is small, and high purity gold ingots can be obtained.
.jpg "Disadvantages of Carbon in Pulp Process (CIP)")
Carbon in Pulp Process (CIP) also has some disadvantages, mainly including the following three points.
① All pulp entering the carbon slurry adsorption circuit needs to be screened (the screen is generally 0.589mm). Cyanide leaching and carbon slurry adsorption are carried out in different circuits, and the capital construction cost is still high.
② The retention of gold and silver in the carbon slurry process is large, and a large amount of gold loaded carbon is retained in the adsorption circuit, resulting in a serious backlog of funds.
③ The wear problem of activated carbon has not been completely solved. Although many effective measures have been taken, some of the worn fine gold loaded carbon is still lost in the tailings, reducing the recovery rate of gold. In the future, we should further improve the process and develop more efficient equipment to simplify the process and reduce the wear of activated carbon.
