/kloc-in the 0/7th century, China used silica sand as molding material to make castings such as clocks, mirrors, pots and cannons. However, in the early days, natural silica sand containing clay, namely mountain sand and river sand, was used, which had good plasticity and could be directly used to make molds and cores, and was suitable for manual production at that time. After the castings enter the industrial mass production, especially after the molding mechanization, the performance uniformity of this natural silica sand containing clay is poor, and the quality of molding sand is difficult to control, which can not meet the technological requirements. So a sand factory was set up to wash, scrub and select natural silica sand to obtain various high-quality silica sand. Artificial silica sand made by casting sand or crushing silica. At the same time, it also expands the use of various non-silica sand. The application and development of resin sand molding core-making technology put forward higher requirements for the quality of foundry sand, such as less fine powder, small specific surface area and low acid consumption. In addition, there are new requirements for the size, shape and particle size distribution of sand grains.