Water circulation in sand washing plant

In the sand washing plant, water runs through the whole process of the whole production line. How to reasonably design the water circuit and how to reuse the water produced in each section of the sand washing plant after treatment are very important issues.

In the sand washing plant, quartz sand grinding, classification, desliming, magnetic separation, flotation , acid pickling and other processes, a lot of water is used, and the role of water is also very diverse. Such as grinding, flotation, need to use water to adjust the pulp to the appropriate concentration, magnetic separation need to use water to wash tailings discharge, slurry pump pool need to use water to adjust pulp concentration. A large amount of water is used in all aspects of production, so the production water should be treated and reused, which can greatly save water consumption. Only a small amount of new water needs to be added to the system. After the tailings and concentrate are concentrated, precipitated and treated, the water is recycled and reused in production. Generally, the water produced by sand washing plant is in the following aspects.
1.Desliming and washing sewage water
After washing and desliming treatment of quartz sand, a large amount of sewage containing mud and fine materials is produced. This part of water is generally discharged into the thickener. After concentration and pressure filtration, the concentration is increased from 10% to more than 80%. Most of the clean water is recovered and used in the system.

2.Flushing water of magnetic separator
The flushing water of quartz sand magnetic separation system is discharged together with the magnetic material, and generally enters the magnetic material tailings pond for sedimentation. After concentration treatment, a large amount of clean water is recovered, which can be reused as the flushing water of magnetic separator.

3.Flotation wastewater
The flotation process shall be carried out in flotaiton machine by adding reagents under acidic conditions. Some of the water containing acid and reagents will be discharged into the tailings into the flotation tailings sedimentation tank, while the other part of acid washing and reagent water will enter the flotation concentrate. The flotation concentrate shall be de-acidated by the screw sand washer, and then the flotation wastewater shall be discharged into the tailings sedimentation tank. The flotation tailings sedimentation tank contains acid and flotation reagent. This part of water shall be treated separately, and then reused in the flotation system without any discharge, so as to ensure that there is no pollution to the environment.

4. Acid pickling wastewater
The quartz sand after pickling needs to be diluted with clean water to remove acid. The acid water after deacidification enters the pickling sedimentation tank. After sedimentation, alkaline substances are added to obtain neutral water quality, which can be reused.

Above are several common water treatment stages in sand washing plant. After the above water is treated, they can be reused in production. When designing the sand washing plant, it is necessary to calculate the water consumption, design the capacity of thickener and sedimentation tank water, and ensure sufficient production water consumption.