How to thoroughly wash away the soil in the sand?

Silica Sand is one of the important raw materials for concrete. Concrete has strict standards for the amount of soil in the finished sand. So how to thoroughly wash away the soil in quartz sand?
Harmfulness of soil to sand
The quality of sand directly affects the quality of concrete. Concrete made of sand with high soil content not only has low quality, but also has the following hazards.
1.Sand with high soil content will reduce the setting force of cement slurry on coarse aggregate, thus reducing the strength of concrete, which will directly affect the durability of concrete. Sand with high soil content will affect the uniformity of concrete and form unsealed air space. In the case of freeze-thaw, the shrinkage of soil is different from that of concrete, which has a greater impact on the durability of concrete.
2.The soil in the sand has a certain adsorption effect on the additive, which can significantly reduce the slump of concrete, thus reducing the bond strength of concrete and the tensile strength of concrete, and making the concrete easy to crack.
3. If the soil content of sand is too high, the internal friction between cement and gravel will decrease, but the internal stress will increase, which will lead to sliding cracking and reduce the strength, and may also cause steel corrosion and reduce the strength of steel.
4. Sand with high soil content will weaken the bond between concrete members, increase the micro seepage channel of concrete, increase the drying shrinkage of concrete, and reduce the impermeability and frost resistance of concrete.

Generally speaking, the high soil content of sand increases the water consumption of concrete, makes its plasticity worse, shrinkage increases, strength decreases and easy to crack.
Therefore, it is necessary to reduce the soil content of sand to meet the standard.
So how to thoroughly wash away the soil in the sand?
In the sand washing plant, the efficient sand washing system is used to clean the sand, which can thoroughly remove the soil in the sand. The sand washing system has three functions: cleaning, dewatering and classifying. The sand washing system consists of vibrating screen, sand washing machine, dewatering screen, fine sand washing recovery machine and auxiliary equipment. The screened sand is washed and dehydrated under the strong water flow of the sand washer, and most of the soil in the sand is removed and filtered, which can reduce the soil content of the sand to the greatest extent. The grade of the finished sand can be controlled by controlling the parameters of the sand washer, so as to greatly improve the quality of the finished sand.

The sand washing machine system should go through the following steps.
1.Screening
The sand is transported to the vibrating screen through the silo for cleaning and screening to achieve preliminary cleaning.
2.Sand washing
The screened materials are sent to the sand washing machine for cleaning. According to the soil content of sand, one or more stages of sand washing is arranged. Generally, for sand with soil content less than 10%, one to two stages of sand washing is recommended. For sand with soil content of 10-20%, two to three stages of sand washing is recommended. The higher the soil content is, the more sand washing stages are used to ensure that the sand is thoroughly washed.
3. Dewateting:
The cleaned materials are sent to the dewatering screen for dehydration.
4.Fine sand recovery:
The tailings after sand washing are separated by fine sand recovery machine to recover fine sand.
5.The washed sand is sent to the finished product pile by belt conveyor to avoid secondary pollution.