Molding sand and preparation method thereof

Abstract

The invention discloses molding sand. The molding sand is characterized by being prepared from the following materials in parts by weight: 200-240 parts of quartz sand, 30-35 parts of sericite, 60-70 parts of kaolin, 30-40 parts of calcium carbonate, 10-15 parts of coke powder, 10-15 parts of clays, 2-4 parts of titanium dioxide, 4-5 parts of aluminum oxide powder, 20-30 parts of argil, 3-4 parts of asphalt, 10-15 parts of bentonite, 3-4 parts of ammonium dihydrogen phosphate, 4-5 parts of sodium metasilicate, 2-3 parts of sodium dodecyl benzene sulfonate and an appropriate amount of water. According to the invention, the quartz sand, the sericite and the kaolin are used and roasted to achieve abundant pores and good gas permeability, moreover, mobility is good, and grinding of added calcium carbonate, clay, titanium dioxide, asphalt, and the like is combined, so that the molding sand has excellent cohesiveness, plasticity and heat stability, and also has high collapsibility. The molding sand material disclosed by the invention is fine and uniform; a casting piece produced by the molding sand has a smooth surface and a few flaws.

Description

technical field [0001] The invention relates to the field of casting, in particular to a molding sand and a preparation method thereof. Background technique [0002] Molding sand is a material used for molding in casting. Molding sand is generally made by mixing molding materials such as raw sand for casting, molding sand binder and auxiliary additives in a certain proportion. Natural silica sand containing clay can also be used. In the usual molding sand formula for aluminum casting, the particle size of the molding sand is too large or If it is too small, the diameter of the molding sand is too large. Although the air permeability is good, the surface of the aluminum sand parts is rough and the finish is not good. If the diameter of the molding sand is too small, the air permeability of the sand mold is not good, and the aluminum castings have pores. Coal powder clay green sand, which is widely used at home and abroad, is generally made of raw sand, binders, coal powder a...

AI Technical Summary

Problems solved by technology

Molding sand is generally made by mixing molding materials such as raw sand for casting, molding sand binder and auxiliary additives in a certain proportion. Natural silica sand containing clay can also be used. In the usual molding sand formula for aluminum casting, the particle size of the molding sand is too large or If it is too small, the diameter of the sand material is too large. Although the air permeability is good, the surface of the aluminum sand parts is rough and the finish is not good. The diameter of the sand material is too small, resulting in poor air permeability of the sand mold and air holes in the aluminum casting

Coal powder clay green sand, which is widely used at home and abroad, is generally made of raw sand, binders, coal powder additives, etc. and water. It has a certain anti-sticking sand effect, low material cost, and high production efficiency. However, its consumption is large, the emission is serious, and the coal powder is burned and decomposed in the casting process to produce toxic gas pollution.