Gold, as a precious metal, has always been used as currency, a store of value, and jewelry. There are also mines of various sizes distributed around the world, and coconut shell gold activated carbon is used in both heap leaching and coal slurry gold extraction methods. How is coconut shell activated carbon used to extract gold?
In fact, many fruit shell activated carbon can also be used to extract gold, but the effect is not as good as coconut shell activated carbon because the hardness of fruit shell activated carbon is not good, and a lot of gold is lost in the waste liquid. The strength of coconut shell gold activated carbon is also a major reason why it is widely used for gold selection. It has good wear resistance, strong wear resistance, and is not easy to be ground. Otherwise, it will be ground down and eventually lose the adsorbed gold.
The adsorption mechanism of coconut shell activated carbon for gold can be divided into several types:
1. In cyanide solution, gold is adsorbed on the inner surface of activated carbon in the form of ion pairs or neutral molecules, or chelated ions combine with metal ions to precipitate in the pores of activated carbon, where the metal ions come from the solution or the ash content of activated carbon (these metal ions may include Ca, K, Na, etc.).
2. Au (CN) 2- undergoes chemical decomposition to generate insoluble AuCN, which remains in the pores of the charcoal.
3. Partial gold cyanide complexes are reduced to certain compounds containing gold atoms in oxidation states of 0 and 1.
4. Au (CN) 2- or AuCN is reduced to metallic Au.
There are usually two methods for recovering gold from gold loaded charcoal:
1. One is a primitive and simple method, which involves roasting gold loaded charcoal and melting it at high temperatures to obtain gold,
2. Another method is the conventional approach, which involves using a desorption solution to remove the gold cyanide complex, and then obtaining pure gold through methods such as electrolysis.
