Gray iron casting moulding sand and preparation method thereof

Abstract

The invention discloses gray iron casting moulding sand which is prepared from the following raw materials in parts by weight: 250-280 parts by weight of quartz sand, 40-45 parts by weight of sepiolite, 160-170 parts by weight of loess, 30-35 parts by weight of shell powder, 20-25 parts by weight of titanium dioxide, 40-45 parts by weight of grass meal, 2-3 parts by weight of acrylic emulsion, 30-40 parts by weight of silicon carbide, 10-15 parts by weight of pulverized coal, 50-60 parts by weight of gypsum, 3-4 parts by weight of zinc stearate, 10-15 parts by weight of bentonite, 3-4 parts by weight of ammonium dihydrogen phosphate, 4-5 parts by weight of sodium bicarbonate, 2-3 parts by weight of sodium dodecyl benzene sulfonate, 4-6 parts by weight of urea, 10-12 parts by weight of flour, 40-45 parts by weight of wood-bamboo powder and a proper amount of water. The sepiolite, the loess, the bentonite and the like are calcined, thus the gray iron casting moulding sand has excellent plasticity and caking property; by using the shell powder, the grass meal, the wood-bamboo powder and the like, the air permeability is increased; by using the titanium dioxide, the dispersity is increased and the high-temperature collapsibility is good; by using the pulverized coal, the surface of a casting is bright. The yield of the casting is increased.

Description

Technical field [0001] The invention relates to the field of casting, in particular to a 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 foundry, molding sand binder, and auxiliary additives in a certain proportion. Natural clay-containing silica sand can also be used. The usual molding sand formulations for aluminum casting have too large a particle size or Too small, the sand diameter is too large, although the air permeability is good, the surface of the aluminum sand part is relatively rough, the smoothness is not good, and the sand diameter is too small, resulting in poor air permeability of the sand mold and pores in the aluminum casting. The pulverized clay green sand, which is widely used at home and abroad, is generally made by mixing raw sand, binders, pulverized coal additives, etc. w...

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.