What are the tailings treatment processes

Tailings are the part of the beneficiation plant that has a low content of useful components and cannot be used for production and is the main component of industrial solid waste. Tailings treatment is one of the important links in mine production, but what are the treatment methods of tailings, do you know?

Why should the tailings be treated?

Usually, the concentrator uses tailings dam storage to treat tailings, and the toxic chemicals, wastewater, and heavy metal ions remaining in the beneficiation process will not only cause pollution and ecological damage to the surrounding environment of the mine but also increase the safety of the tailings dam. Hidden hazards, such as landslides, mudslides, tailings dam failures, etc., have been induced in dumps. Therefore, tailings management has always been paid attention to.

Method of tailings treatment

At present, tailings treatment methods generally have three directions: tailings re-selection, tailings dewatering, and tailings filling the goaf. Below we will explain these three parts separately.

1. Re-selection process of tailings

Although the content of useful components in the tailings is relatively low, the use of advanced technology and reasonable technology to re-select the tailings can also recover the useful components in the tailings to a greater extent, so that resources can be fully recycled and reduced. The final output of tailings will ease the pressure on the environment from tailings. At present, the common tailings redressing process includes

1) Flotation process

The flotation process is used to treat tailings containing colemanite, zinc oxide, apatite, and other minerals. Due to the development of new reagents and new processes, some relatively simple process tailings, especially old tailings, can be re-floated. Concentrate products that can be recycled can be obtained by processing.

2) New reselection process

Use new gravity separation equipment to recover fine-grained minerals in tailings. After being invented and improved, much traditional new gravity separation equipment can be used in the reselection of fine and ultrafine tailings, such as vertical centrifugal concentrators, compound stand shakers, compound force field centrifuges, and so on.

3) Microbial treatment and leaching technology

This technology mainly uses the biochemical action of microorganisms to improve the properties of tailings and extracts harmful metal ions in the tailings through microbial leaching or microbial mineralization to avoid environmental pollution.

2. Tailings dehydration process

In the separation stage, the slurry often contains a lot of water, and the excessive water content of the tailings can easily cause the tailings dam to break. Therefore, in the beneficiation plant, tailings concentration and dehydration are also important links, and the following two aspects are common.

1) Concentration process with hydrocyclone as the core

As a kind of equipment that uses centrifugal force for solid-liquid separation, hydrocyclone has the characteristics of a small footprint and high underflow concentration. This kind of concentration process mainly uses hydrocyclone and thickener to form a series of closed-circuit processes to obtain high concentrations. The concentrated product.

2) Tailings filter press process using a filter press

In the tailings treatment of gold mines, filter press dehydration is also used. This method has the characteristics of low water content in the filter cake and reusable filtrate. However, due to the low processing capacity of a single machine, it is difficult to separate large-scale beneficiation tailings. use.

3) Dry tailings discharge

Dry tailings discharge is a new type of technology that uses dehydration cyclones, high-efficiency high-frequency dewatering screens, high-efficiency deep cone thickeners, and other equipment. It can reduce the water content in tailings to less than 15%, save costs, and effectively avoid the environment. Pollution.

3. Filling the mined area with tailings

Tailings filling the mined-out area is to use the tailings waste material to refill the mined-out area after treatment, which can achieve the functions of protecting the terrain and reducing the cost of the tailings dam. At present, there are two main methods for filling the goaf with tailings:

1) Full tailing cement filling technology

Full tailings cementation filling uses dehydrated tailings mixed with cement, fly ash, etc. to form a filling aggregate with a hardness of 1 to 2 MPa. The filling slurry is sent to the filling area by the self-flow of the pipeline to achieve the purpose of filling the goaf.

2) High-water consolidation and full tailings filling technology

High-water consolidated full tailings filling is similar to full tailings cemented filling, except that high-water materials are used as cementing materials instead of cement. This method uses the first material mainly composed of aluminate and sulfoaluminate and the second material mainly composed of anhydrite, quicklime, and coagulant, which are respectively pulped and transported, and mixed before filling, which has a fast setting speed. Features.

The above three aspects are the three directions of tailings treatment. The actual application of the concentrator needs to be determined according to the scale and investment of the concentrator. It is recommended to consult a beneficiation equipment provider with the design qualification of the concentrator to choose a suitable concentrator The tailings treatment process of the situation.