Gold mine cyanide tailings are waste or residues generated during the gold ore beneficiation process. In gold ore beneficiation, the cyanidation method is commonly used to extract metallic gold. Cyanidation is a widely used method for gold extraction, involving the dissolution of gold from the ore, followed by separation and extraction through processes such as adsorption, precipitation, and more.
Dealing with gold mine cyanide tailings is a significant issue in mining and environmental management. Cyanide tailings may contain hazardous substances, such as cyanides, so it's essential to take appropriate measures for their treatment and disposal to minimize environmental risks. Here are some methods for handling gold mine cyanide tailings:
1.Reprocessing Gold from Cyanide Tailings
In the early stages of beneficiation development, many processing plants operated in a less efficient manner, leading to valuable minerals being discarded as tailings. This not only increased tailings discharge but also resulted in significant resource waste. Many of these older tailings contain valuable minerals and can be reprocessed. Xin Hai commonly uses a full mud cyanide process with carbon slurry to extract gold from old tailings. After the cyanide process, Xin Hai employs a dry tailings treatment method by using a filtration process to recover the filtrate for water recycling and to remove a significant portion of cyanides from the tailings. This approach not only recovers gold from the tailings, creating revenue but also eliminates harmful components, allowing for water resource recycling, achieving multiple benefits.
2.Dry Stacking of Gold Mine Cyanide Tailings
For gold mine cyanide tailings that cannot be economically reprocessed, the dry stacking method can be employed. This involves removing water and hazardous cyanide components, leaving behind dry tailings with a moisture content of less than 15%. Dry tailings can be used in applications such as processing building materials and backfilling of mined-out areas, and water resources can be recycled.
The choice of tailings dry stacking method depends on the particle size of the tailings and can be determined as follows:
Coarse-grain Tailings: Mainly utilize hydraulic cyclones, deep cone thickener, high-frequency dewatering screen, and slurry pump. This method has the advantages of simplicity, high processing capacity, and excellent drying results.
Medium to Fine-grain Tailings (with a concentration greater than 10%): A closed-loop system utilizing hydrocyclones and dewatering screens. This method improves the efficiency of the dewatering screen and leaves the discharged tailings for further dry stacking using a belt filter press.
Fine-grain Tailings: The combination of a hydrocyclone, dewatering screen, and a filter press. The inclusion of the filter press significantly improves the dry stacking efficiency, especially for fine-grained tailings.
Ultra-fine-grain Tailings: Using a thickener and filter press in combination, with a slurry pump for transportation. This approach simplifies equipment selection, but the filter cloth for the filter press needs to be finer, resulting in lower processing efficiency and higher operating costs.
Gold Reprocessing Equipment:
In this process, you would need equipment for gold cyanidation such as desorption and electrolysis system, leaching agitation tank, and zinc powder replacement device. If the reprocessing method involves flotation, flotation machines and agitation tanks may also be used.
Tailings Dry Stacking Equipment:
Equipment commonly used for tailings dry stacking includes high-frequency dewatering screens, deep cone thickeners, filter presses, hydrocyclones, and slurry pumps. These are combined in various ways to efficiently achieve dewatering and dry stacking of tailings.
Handling gold mine cyanide tailings is a complex task that requires a comprehensive consideration of environmental, legal, safety, and economic factors. Xin Hai's tailings management solutions ensure the recycling of tailings resources and avoid negative environmental impacts. The nature of tailings and the processing method may vary for different ore types. Therefore, when dealing with gold mine cyanide tailings, specific measures should be taken based on the individual circumstances.
