Molding sand for gray iron casting and preparation method thereof

Abstract

A molding sand for gray iron casting, made of the following raw materials in parts by weight: 250-280 parts by weight of quartz sand, 40-45 parts sepiolite, 160-170 parts loess, 30-35 parts shell powder, 20-25 parts titanium dioxide, and 40 parts grass powder -45, acrylic emulsion 2-3, silicon carbide 30-40, coal powder 10-15, gypsum 50-60, zinc stearate 3-4, bentonite 10-15, ammonium dihydrogen phosphate 3-4, sodium bicarbonate 4-5, 2-3 sodium dodecylbenzene sulfonate, 4-6 urea, 10-12 flour, 40-45 wood bamboo powder, appropriate amount of water. The present invention uses sepiolite, loess, bentonite, etc. after being calcined, and has excellent plasticity and cohesiveness. By using shell powder, grass powder, wood bamboo powder, etc., air permeability is increased, and titanium dioxide powder is used to increase dispersion. Good high-temperature collapsibility; by using coal powder, the surface of the casting is bright, and the invention improves the yield of the casting.

Description

technical field [0001] The invention relates to the field of casting, in particular to molding sand for gray iron casting 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, bi...

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.