The invention discloses highly fire-resistant
foundry sand for
steel casting and a preparation method of the highly fire-resistant
foundry sand. The highly fire-resistant
foundry sand is prepared from the following raw materials in parts by weight: 50-80 parts of fused ceramite, 10-15 parts of high-
alumina cement, 17-23 parts of
sludge dry powder, 20-30 parts of volcanic tuff, 15-25 parts of
dickite, 16-22 parts of natural
manganese sand, 8-12 parts of nacrite, 10-15 parts of
asbestos powder, 5-10 parts of aluminum dihydrogen tripolyphosphate, 10-15 parts of modified
bentonite, 4-8 parts of alumn
powder, 3-6 parts of
cellulose glycolate, 2.5-4.5 parts of
corn syrup, 4.5-6.5 parts of
beryllium oxide, 3-5 parts of China wood oil, 4-6 parts of
sodium metasilicate, 2-4 parts of
polyethylene glycol and an appropriate amount of water. Compared with conventional foundry sand, the highly fire-resistant foundry sand provided by the invention is not only excellent in fire-resistant performance, can maintain a higher strength and relatively low
thermal expansion coefficient under high temperature, does not easily cause expansion and breakage, has excellent
plasticity, air permeability and collapsibility, can remarkably improve the surface quality of castings and improve the finished product rate of castings.