Gold Mine Cyanidation-Carbon Pulp Adsorption Mineral Processing Technology

In the field of gold mine mineral processing, a variety of technologies are employed. Among them, common methods include gravity separation, amalgamation, flotation, and cyanidation. Less common ones consist of carbon pulp adsorption, ion exchange, and high - temperature roasting. Experts from Xingyang Mining Machinery Factory in Henan Province will elaborate on the detailed technological processes and specific operation methods of gold mine cyanidation and carbon pulp adsorption in this article.

1. Gold Mine Cyanidation Method

The cyanidation process typically begins with two - stage closed - circuit crushing using a jaw crusher and a cone crusher. Subsequently, the material undergoes grinding in a ball mill and flotation in a flotation machine. After that, a thickener is used to remove the excess moisture from the gold - bearing sulfur concentrate. This not only increases the slurry concentration but also eliminates the flotation reagents in the slurry that are harmful to cyanidation.

The concentrate is then sent for fine grinding to further liberate the gold particles. Next, a dilute cyanide solution is used. Under oxygen - rich conditions, the gold is leached in the agitation tanks. The leached pulp is washed to separate the gold - bearing solution from the solids, yielding pregnant solution and cyanide tails.

The pregnant solution undergoes purification and deoxygenation treatment. Then, metallic zinc is used for displacement, resulting in gold sludge and lean solution. The gold sludge is sent to the gold - smelting workshop to obtain bullion, which can be further processed into gold ingots of higher purity. The lean solution can be recycled in the process or discharged after purification treatment.

2. Gold Mine Carbon Pulp Adsorption Method

The carbon - in - pulp (CIP) gold extraction process is one of the cyanidation gold extraction methods. It is a technological process in which activated carbon adsorbs monovalent gold cyanide after the completion of cyanide leaching of gold - bearing materials.

The CIP process is mainly suitable for gold - bearing oxidized ores with a high mud content. Due to the high mud content in the ore, solid - liquid separation is difficult. Activated carbon can adsorb precious metals from the solution and directly adsorb gold from the cyanide pulp, eliminating the need for solid - liquid separation operations.

CIP Process Flow

1. The gold - bearing material is crushed and ground to a suitable cyanidation particle size, generally requiring less than 28 mesh. Impurities such as wood chips are removed. After that, the material is concentrated and dehydrated to achieve a leaching pulp concentration of 45 - 50%.

2. Stirring leaching is usually carried out in 5 - 8 agitation tanks. The cyanide pulp then enters the agitation adsorption tank, where activated carbon and the pulp flow counter - currently to adsorb the dissolved gold in the pulp.

3. Desorption of gold - loaded carbon: Desorption of gold - loaded carbon can yield a high - grade pregnant solution with a gold content of up to 600 g/m³. Gold powder is obtained through electrowinning or zinc displacement and is sent for smelting to obtain gold ingots.

Desorption Methods of Gold - Loaded Carbon

1. Desorption with hot caustic sodium cyanide solution.

2. Desorption with caustic sodium cyanide solution added with alcohol.

3. Desorption with caustic sodium cyanide solution under heating and pressurized conditions.

4. Desorption with high - concentration caustic sodium cyanide solution.

Recycling of Activated Carbon

After desorption, the activated carbon is first washed with dilute sulfuric acid (or nitric acid) to remove accumulations such as carbonates. After several cycles of use, thermal activation is required to restore the adsorption activity of the carbon.

The gold mine cyanidation - carbon pulp adsorption process is a new type of mineral processing technology in the gold mine industry. It is especially suitable for oxidized gold mines with a high mud content. Through technology introduction and innovation, Xingyang Mining Machinery, a gold mine mineral processing equipment manufacturer in Henan, has continuously overcome a series of challenges in the cyanidation - carbon pulp adsorption process. This has further enhanced the advantages of this gold mine mineral processing technology, improving the gold recovery rate and grade.