Technology process of foundry sand

This paper describes in detail the production process of foundry sand by using natural quartz stone.
 
Natural foundry sand is a kind of natural quartz sand, which is suitable for all kinds of casting sand. The silica content is required to reach 97% - 99%. According to the needs of casting products, the specifications are 1-2 mesh, 2-4 mesh, 4-6 mesh, 6-8 mesh, 8-10 mesh, 10-20 mesh, 20-40 mesh, 40-70 mesh, 70-100 mesh, 100-140 mesh and above 140 mesh to 400mesh. The appearance of natural quartz sand for casting is polyhedral, spherical and pure white, which is characterized by high hardness, low iron content, high fire resistance, strong pollution resistance, good acid resistance, etc. in addition, the quartz sand size is determined according to the casting types used, such as resin sand casting, sodium silicate sand casting, lost foam casting and the requirements of casting material, casting size and surface finish, etc., the particle size requirements are generally selected within 40-90 mesh, so as to ensure the casting's quality Smooth and flat, greatly reducing the rework rate of castings.



Sinonine provides a method for industrial production of natural foundry sand. The method takes natural quartz stone as the main raw material, and produces foundry sand by cleaning, peeling, crushing, pickling, washing, drying, magnetic separation, gclassifing and other processes of natural quartz stone. The method has the advantages of using general equipment, less investment, low cost, no pollution and mass production The raw materials used to produce foundry sand are natural quartz stone, dilute hydrochloric acid with concentration of 14% - 16%, and water.



The production process of natural foundry sand consists of the following steps:
 
1.Send the selected large natural quartzite into the water washer, wash it with high-pressure water, remove the attachment on the outer surface of quartzite, and then send the cleaned large quartzite into the peeling machine to remove the yellow skin on the outer surface of the large quartzite.
 
2.Send the peeled large quartz stone to the crusher to be crushed into granular quartz sand, then send the quartz sand to the acid tank, and soak it in dilute hydrochloric acid with concentration of 14% - 16% for 24-30 hours.
 
3.After the acid pickling, the natural quartz sand in the acid tank shall be fished out, immediately sent to the sand washing machine for washing with high-pressure water, washed away the hydrochloric acid on the surface of quartz sand particles, and sent to the sand dryer for drying. The drying temperature is 70 ℃ - 80 ℃, and the drying time is 2.5-3.0 hours.


4.Send the dried natural quartz sand to the dry magnetic separator, remove the quartz sand containing magnetism, metal and metal oxide through the magnetic separator, and then send it to the vibrating screen for classification. The quartz sand is divided into 1-2 mesh, 2-4 mesh, 4-6 mesh, 6-8 mesh, 8-10 mesh, 10-20 mesh, 20-40 mesh, 40-70 mesh, 70-90 mesh, 90-140 mesh and 140-400 mesh, and is packaged for final foundry sand products.



The method has the advantages of simple process, convenient operation, less equipment investment, low cost, no pollution and mass production, and can produce high-quality natural foundry sand.