Dry tailings discharge is a new tailings treatment technology that has gradually emerged at home and abroad. After the tailings slurry is concentrated in multiple stages, it is processed by high-efficiency dehydration equipment such as dehydration vibrating screens to form a small water content, easy to precipitate and solidify and use The slag stored on the site can be transferred to a fixed location for dry storage.

According to different tailings types, particles, concentrations, and mud content, rationally formulating tailings dry discharge technology and selection of tailings dry discharge equipment can minimize the area and save equipment on the premise of ensuring dry discharge. investment. Below, I will take you to understand the five common dry tailings process schemes and help you choose a suitable dry tailings process scheme.

1. Cyclone-thickener scheme

The beneficiation tailings with a concentration of 10%-20% are fed into the cyclone by a slurry pump, and the overflow of the cyclone is fed into the thickener to concentrate fine particles. The overflow of the thickener is clarified water and returns Production recycling water reuse. The concentration of the cyclone sedimentation and the underflow of the thickener is 45%-50%.

This dry tailings discharge process scheme makes full use of the differences in the different particle sizes of tailings, prioritizes the concentration of large particles, increases the processing capacity of the thickener, and reduces the diameter of the thickener. The investment is saved, but the concentration of the discharged tailings is not high and it is not easy to dry up.

2, filtering scheme

The beneficiation tailings are fed into the thickener, and the underflow of the thickener is fed into the filter. The filtered filter cake contains 15%-20% water and can be directly drained. The overflow water and filtered water of the thickener are returned to the production circulating water for reuse.

This dry tailings discharge process can obtain materials with lower water content to achieve the purpose of direct dry discharge and is convenient for transportation. It is worth noting that the dry tailings process plan requires the use of a large-scale thickener, which covers a large area and high investment, so it is not suitable for the tailings treatment of large and medium-sized concentrators.

3. Two-stage concentration-filtration scheme

Using a cyclone as a first-stage thickening equipment, the tailings slurry is fed into the cyclone, the overflow of the cyclone is fed into the thickener, the underflow of the cyclone and the underflow of the thickener are combined to the filter, and the thickener overflows Flowing water and filtered water are returned to production circulating water for reuse. After filtration, the filter cake contains 15-20% water and can be directly drained.

The advantage of this tailings process is that the one-stage dewatering of the cyclone greatly reduces the workload of the thickener, which can clarify the overflow water of the thickener, avoid running muddy, and The specification of the thickener is also reduced, the area is small, and the investment cost is reduced. However, the workload of the filter is large, and a large-size filter or multiple filters are required, and the energy consumption is high.

4. Two-stage concentration-dehydration program

The beneficiation tailings are fed into the cyclone, the overflow of the cyclone is fed to the thickener, the overflow water of the thickener is returned to the production cycle water for reuse, and the underflow of the cyclone is concentrated The underflow is fed into the dewatering screen, the material on the dewatering screen contains 20%-25% water for dry discharge, and the under-screen material is returned to the thickener.

This dry tailings process plan uses a dewatering screen to dewater, reducing filter equipment, saving electricity and reducing investment costs. However, the fine-grained materials under the dewatering screen are returned to the thickener to form an infinite loop, which affects the concentration effect and makes the concentrated and clarified water run out of mud. Finally, the under-screen material of the dewatering screen is discharged into the tailing pond, failing to achieve all dry discharge.

5. Two-stage concentration-segmented dehydration and filtration scheme

The beneficiation tailings are fed into the cyclone for gravity separation, the fine particles and water are fed into the thickener, and the clarified water of the thickener is returned to the production circulating water for reuse; the bottom flow of the cyclone is fed into the dewatering screen and the dewatering screen The content on the sieve contains 15%-20% of water for dry discharge; the underscreen material is fed into the filter with the underflow of the thickener. After the filter is separated, the filter cake contains 15%-18% of water for dry discharge. The liquid is filtered and the filter The cleaning water returns to the thickener to form a closed loop.

This tailings dry discharge process plan uses cyclones and dewatering screens to first separate coarse and heavy particles and then dry discharge them, reducing the workload of thickeners and filters. The specifications of the thickener and filter are greatly reduced, the floor space is small, and the investment cost is reduced. The under-sieve of the dewatering screen is fed into the filter to ensure solid-liquid separation, which is convenient for all dry discharge to realize long-distance transportation of tailings. The drain and cleaning water of the filter is returned to the thickener, which not only ensures the content of solid particles in the reused water, but also meets the quality of the production water.

With the release of the national “green mine” standard, the dry tailings process has shown great advantages in terms of economy, environment and safety, and has become the future tailings treatment An important choice. In the actual application of the concentrator, it is recommended to choose the dry tailings process plan suitable for the condition of the concentrator according to the scale of tailings, investment, etc., and tailor reasonable dry tailings equipment.