[Introduction]: Gold CIL process (carbon in leach) is an efficient method of extracting and recovering gold from its ore. By cyaniding and carbon leaching crushed gold ore slurry simultaneously, CIL process lowers the gold mining operation cost and increases gold recovery rate to 99%, which is the first choice of modern gold mining and gold beneficiation plant.
[Application]: CIL mainly applies for the process of above 1g/t grade gold ore and gold ore with large bearing ore volume: silver, platinum, copper, etc. And CIL has a better performance in extracting these minerals at the same time.
After the crushing and grinding stage, add 9 step-arranged high-efficiency cyanidation leaching tanks into the pulp. Gold pulp cyanidation is carried on the first two leaching tanks, countercurrent adsorption operation is carried on the last six or seven leaching tanks (cyanidation and adding activated carbon simultaneously).
Compared with gold CIP process and other traditional gold extraction processes, Xinhai gold CIL process greatly shortens the cyaniding time, reduces the capital backlog in the gold retention stage. Taking the gold cyanidation plant with processing capacity of 100000 tons per year and gold grade of 7.5 g/t as an example, gold CIL process can save the investment cost of $486000 than the CIP process, reduce the capital backlog of $201700, save and recycle capital of $675100 in advance excluding the cost of activated carbon.
In the adding activated carbon step, add the coconut shell activated carbon (small hole, high activity, wear-resisting and renewable) specially selected by Xinhai mineral processing design institute into the pulp, which can dissolve and adsorb the gold and silver ions then form the gold loaded carbon according to the characteristics of gold and silver adsorption.
Compared with the traditional gold extraction process, Xinhai gold CIL process ensures the gold and silver dissolution and the adsorption of activated carbon synchronously, which will not be affected by the excessive ion concentration, greatly improves the recovery rate of the precious metals (such as silver and copper) in the associated metals , and significantly improves the economic benefits.
Vibrating screen and dewatering screen are the key equipment for the reverse movement of pulp and carbon. Filter press and high frequency dewatering screen developed by Xinhai can effectively reduce the carbon wear on the surface of vibrating screen and in the process of continuous slurry pumping, and reduce the cost, facilitate the maintenance and operation.
Air lifter used in the agitation process can make the slurry carry on small minor-cycle. Compared with other agitation tanks, Xinhai air lifter can reduce the power consumption by 70%, making the solid materials uniformly suspended, the activated carbon less worn, and the gold recovery rate higher, which is an important equipment in a modern cyanide plant.
Xinhai desorption electrolysis system implements high-temperature desorption electrolysis on gold in the gold-loaded carbon through the mixed liquor of sodium cyanide and sodium hydroxide. After wood chips and other sundries are removed by washing machine, and the gold desorption is carried out by Xinhai high-temperature and high-pressure desorption method (150 degrees and 0.5Mpa), which can resolve 99% of gold within 2-6 hours.
The pregnant solution obtained by the desorption of gold-loaded carbon contains higher concentration of gold and silver cyanidation complex ions, while the impurity ions are greatly reduced, which provides an ideal solution for the reduction and recovery of gold from the pregnant solution by electrodeposition. Finally, with Xinhai desorption electrolysis system, the solid gold with high purity can be obtained safely and economically.