Dry tailings discharge is a new tailings disposal process, which dewaters the tailings through multiple stages to form tailings slag with low water content, which is stacked in the tailings pond in the form of dry slag, eliminating the need for traditional wet discharge to tailings. The dam break damage caused by the mine depot reduces environmental pollution and land occupation, and the tailings after dry discharge can be reused, such as filling goaves, building materials, roads, and fertilizers.

Most of the tailings dry discharge process is a combination of the following equipment.

1. Thickener + ceramic filter

Features: This group of equipment is mainly suitable for the dehydration and dry discharge of medium and fine-grained tailings particles. It is difficult to dewater the coarse-grained tailings. Moreover, the production cost of this group of processes is high, and the filter plate of the ceramic filter is easily blocked. , and difficult to clean. It can be said that this group of equipment has great limitations, but its dehydration efficiency is high, and the dehydration component can be as low as 10% or less. Comprehensive consideration is suitable for investment and use by medium and large enterprises.

2. Thickener + box filter press

Process: After the tailings slurry produced by the concentrator is concentrated by a high-efficiency thickener, the slurry is pumped to the filter press workshop for stirring and pressure filtration. After sufficient extrusion, a flaky tailings cake is formed. The tailings filter cake is transported by belt conveyor and stored in layers in dry tailings yard.

The filtered water enters the sedimentation tank, and the upper part of the sedimentation tank overflows into the clean water tank. The clean water in the clean water tank is pressurized by the water pump and used for the production of the concentrator. The fine-grained tailings slurry in the bottom of the sedimentation tank is pressurized by the submersible mud pump and sent to the mixing tank, and then enters the filter press process. After this process, the tailings can be drained dry without the tailings slurry being discharged, and all the backwater can be used.

Features: This group of equipment is also only used for dehydration of medium and fine-grained tailings, and the moisture can be as low as 15-20%, but the loss and cost of the filter press are high, and the service life can generally only be maintained for 1-3 months, and Its discharge is discontinuous, and some processes need to set up buffer equipment. But what is important is that this group of equipment has a large production capacity, and large-scale mining enterprises mostly use this process.

3. Thickener + cyclone + belt filter

Features: This group of processes applies the cyclone to the tailings dry discharge process and is only suitable for medium and coarse-grained tailings, and the product dehydration can be as low as 15%-18%. However, this group of equipment has been put into operation, the cost is high, the power consumption of production and operation is high, and the cost of dry discharge is even higher than the cost of beneficiation.

4. Hydrocyclone + high-efficiency deep cone thickener + high-efficiency multi-frequency dewatering screen

Using a slurry pump, the slurry containing -0.074mm particle size within 65% is sent to the hydrocyclone group for preliminary concentration and dehydration, the fine-grained underflow enters the high-frequency tailings dry discharge screen, and the coarse-grained overflow enters the high-efficiency The deep cone thickener performs secondary dehydration, and the underflow of the thickener continues to be dewatered by the tailings dry discharge screen. Oversize material with a moisture content of less than 15% was recently obtained.

5. Multi-stage variable cone cyclone + dewatering screen + high-efficiency thickener without rake

This process is similar to the previous one, but the specific equipment is slightly different. The multi-stage variable cone structure of the high-efficiency cyclone improves the classification efficiency, and the separation particle size can be reduced by 20% to 30% compared with the conventional cyclone, which lays a foundation for the efficient operation of the dry discharge process. Through the introduction of the high-efficiency thickener without a rake, the problem of efficient dewatering of fine and fine tailings has been fundamentally solved, and the efficient operation of the dry discharge process has been guaranteed.