Activated Carbon Application--Gold Extraction

There are three main classifications of activated carbon for gold extraction, including coconut shell activated carbon for gold, apricot shell activated carbon for gold, and wood column activated carbon for gold.

Activated carbon for gold is characterized by uniform granularity, strong adsorption, high abrasion strength, etc. It is suitable for modern gold mining production.

Activated carbon has a high degree of adsorption performance, can effectively remove impurities in gold, such as silver, copper, iron, etc., to improve the purity and quality of gold.

At the same time, it also has good chemical and thermal stability, and can be used in high temperature and strong acid and alkali environment without deformation and breakage.

There are several main methods of gold extraction, which are implemented by adding activated carbon into the process:

(i) Heap leaching or carbon slurry method for gold extraction: Activated carbon for gold is mainly used in the separation and extraction of precious metals in the heap leaching or carbon slurry method for gold extraction in the metallurgical industry. In these methods, activated carbon can efficiently adsorb the gold elements in the solution, thus realizing the enrichment and recovery of gold elements.

(ii) Amalgamated gold extraction: Although the amalgamated gold extraction process is an old gold extraction process, it is still used in some gold mines. With the progress of technology, amalgamation gold extraction process has been improved and perfected, activated carbon in which also plays a certain role.

(C) cyanide gold extraction process: this is the main method of extracting gold from ore or concentrate in modern times. In cyanidation gold extraction process, activated carbon can directly recover gold by adsorption from cyanide slurry without filtering and washing, which improves the extraction efficiency.

The specific steps of activated carbon in gold extraction are as follows:

(i) Preparation of metal-containing activated carbon: the activated carbon containing gold is collected and cleaned with water or detergent to remove impurities on the surface.

(ii) Reducing the metal: the collected activated carbon is placed in a furnace and the metal is reduced by heating and adding a reducing agent. During the reduction process, metallic gold is reduced by the reducing agent and can be separated from the activated carbon.

(iii) Separation of gold: The activated carbon is taken out of the furnace and the useless impurities are removed by screening and other methods, and only the metal particles containing gold are retained.

(iv) Re-smelting: The gold in the activated carbon is smelted again to remove any residue and obtain pure gold.

However, activated carbon has limitations in gold extraction:

(i) Higher cost of activated carbon: It may increase the cost of gold extraction, thus affecting the gold recovery rate.

(ii) Complicated regeneration process of activated carbon: the regeneration process requires specific equipment and process, the operation is more complicated, and the regeneration effect may gradually decrease, which may lead to the shortening of the service life of the activated carbon, and the need to replace the activated carbon more frequently, thus increasing the cost and lowering the gold recovery rate.

(iii) Non-selective adsorption of impurities: activated carbon will not only adsorb gold ions, but may also adsorb other impurity ions, which may affect the purity of the gold and the subsequent treatment, thereby reducing the gold recovery rate.

(iv) Limited adsorption capacity: the adsorption capacity of activated carbon has certain limitations, and for large-scale gold extraction operations, a large amount of activated carbon may be required to meet the demand, which may increase the cost and reduce the gold recovery rate.

(v) Highly influenced by environmental factors: Changes in environmental conditions such as temperature and pH value may affect the adsorption performance of activated carbon, thereby affecting the efficiency and effectiveness of gold extraction and thereby reducing the gold recovery rate.