Tailings are wastes generated by the ore dressing plant. Although they are wastes, some tailings still contain useful components, but the content is relatively low. Two methods are often used in tailings treatment, one is tailings dry discharge, and the other is tailings re-selection. Tailings dry discharge is a dehydration treatment method for tailings that do not need to be re-selected, while tailings re-selection is for tailings that contain useful components and have re-selection value. Below we introduce these two tailings treatment methods respectively.
During the selection stage, the slurry often contains a large amount of water. If the tailings have too high a water content, it is easy to cause a tailings dam breach. Therefore, in the beneficiation plant, tailings dry discharge and dehydration is also an important link. Common tailings dry discharge processes include:
1.Dry stacking process with hydrocyclone as the core
As a device that uses centrifugal force to separate solids and liquids, the hydrocyclone has the characteristics of small footprint and high bottom flow concentration. This type of concentration process mainly uses hydrocyclones and thickeners to form a series or closed-loop process to obtain a high-concentration concentrated product.
2.Tailings filter press process using filter press
Filter press dehydration is widely used in the treatment of tailings in gold mines. This method has the characteristics of low filter cake water content and filtrate return for use, but due to the low processing capacity of a single machine, it is difficult to use it alone for large-scale beneficiation tailings dehydration.
Although the content of useful components in tailings is relatively low, the use of advanced technology and reasonable processes to re-select tailings can also recover useful components in tailings to a large extent, so that resources can be fully recycled, the final tailings output can be reduced, and the pressure of tailings on the environment can be alleviated. At present, common tailings re-selection processes include the following types:
1.Use flotation process to treat tailings containing minerals such as colemanite, zinc oxide, and apatite
Due to the development of new reagents and new processes, some tailings produced by simple processes, especially old tailings, can be processed by flotation re-selection to obtain recyclable concentrate products.
2.Use new gravity separation equipment to recover fine-grained minerals in tailings
Many traditional new gravity separation equipment can be used in the re-selection of fine and ultra-fine tailings after being invented and improved, such as vertical centrifugal concentrators, compound force field shakers, compound force field centrifuges, etc.
3.Use microbial treatment and leaching technology to treat tailings
This technology mainly uses the biochemical action of microorganisms to improve the properties of tailings. Through microbial leaching or microbial mineralization, harmful metal ions in tailings are extracted to avoid environmental pollution.
The above are two commonly used methods for tailings treatment. The specific method should be determined according to the properties of the tailings and the test results. In addition, in actual production, the scale of the concentrator, the comparison of investment cost and economic benefits, etc. should also be considered to comprehensively determine the tailings treatment method.
