Casting molding sand and preparation method thereof

Abstract

The invention discloses casting molding sand which is prepared from the following raw materials in parts by weight: 250-270 parts of silica sand powder, 40-50 parts of coal ash, 9-12 parts of aluminum hydroxide, 40-45 parts of rice bran, 20-30 parts of iron-ore slag, 20-30 parts of calcium carbonate powder, 1-2 parts of polycarboxylic acid water reducing agent, 1-2 parts of polyacrylamide, 1-2 parts of tung oil, 45-50 parts of aluminum silicate, 30-40 parts of maize straw powder, 22-30 parts of bamboo carbon, 30-40 parts of clay, 14-18 parts of corn meal, 3-4 parts of silane coupling agent KH-550 and a proper amount of water. Due to adoption of coal ash, the fineness and smoothness degree of the molding sand is improved, the formation is easy, and the energy is saved; due to adoption of the straw powder, the corn meal and the like, the air permeability and the high temperature collapsibility are improved; as the stone powder is sintered and is combined with organic binding agents, the plasticity, the dispersity and the air permeability are improved. The casting molding sand is easy to form and make a core, the shrinkage cavity and shrinkage porosity of a cast piece is reduced by more than 91%, and the finished product rate of the cast piece is improved.

Description

technical field [0001] The invention relates to the field of casting, in particular to a casting 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.