Gold is something we are all familiar with, and its value is self-evident. Since ancient times, many people have been engaged in the metallurgical industry. Activated carbon can also be well applied to the metallurgical field. Many customers will ask: Which activated carbon is the best for extracting gold? I will introduce it in four aspects.
1. Three major categories of activated carbon for gold extraction:
Coconut shell gold charcoal, fruit shell gold activated carbon, and wooden columnar gold activated carbon.
2. Advantages of activated carbon for gold extraction:
Gold-specific activated carbon has uniform particle size, strong adsorption capacity, and high wear resistance. It is suitable for modern gold mining production. It is mainly used for the separation and extraction of precious metals in the gold metallurgical industry by heap leaching or carbon slurry method.
3. Which activated carbon is the best for extracting gold?
Many fruit shell activated carbons can also be used to extract gold. However, after testing, although apricot shell and peach shell activated carbon can be used to adsorb gold, the effect is not as good as coconut shell activated carbon for gold purification. In addition, fruit shell activated carbon has poor hardness. The production process of coconut shell activated carbon is to first crush the raw materials, then screen them, and then process them into coconut shell gold activated carbon through carbonization and high-temperature catalytic activation.
4. The principle of extracting gold from coconut shell carbon:
(1) Gold in cyanide solution is adsorbed on the inner surface of activated carbon in the form of ion pairs or neutral molecules, or complex ions are combined with metal ions and precipitated in the voids of activated carbon. The metal ions come from the solution or the ash of activated carbon (these metal ions may be Ca, K, Na, etc.).
(2) Au(CN)2- undergoes chemical decomposition to generate insoluble AuCN, which remains in the voids of carbon.
(3) Some gold cyanide complexes are reduced to certain compounds containing gold atoms with oxidation states of 0 and 1.
(4) Au(CN)2- or AuCN is reduced to metallic Au.
Activated carbon for coconut shell gold purification is mainly used for gold extraction by heap leaching or carbon slurry method. Coconut shell activated carbon can effectively recover gold directly from cyanide gold-containing solution, and has good selectivity, strong adaptability and can be reused. The activity of coconut shell activated carbon is the key factor to ensure its reuse.
