Preparation method of special inorganic anti-veining additive for casting

Abstract

The invention relates to a preparation method of an additive, and in particular relates to a preparation method of a special inorganic anti-veining additive for casting. The method comprises the following steps: respectively sieving iron oxide red and black iron oxide through a sieve of 70mesh; removing oversize materials and remaining the residues on the sieve for later use; respectively sieving spodumene, kyanite and hollow microspheres through a sieve of 30mesh; removing oversize materials and remaining the residues on the sieve for later use; sequentially feeding the sieved raw materials, potassium carbonate and lithium carbonate into a special agitating device according to a technical formula; then starting to agitate for mixing; discharging after mixing. The special inorganic anti-veining additive has the advantages that the addition quantity is small, the influence on the strength of moulding sand is low, the anti-veining effect is good, and the production cost can be effectively decreased.

Description

technical field [0001] The invention relates to a preparation method of an additive, in particular to a preparation method of a special inorganic anti-veining additive for casting. Background technique [0002] When producing automobile cylinder blocks and cylinder heads, thin burrs or veining defects often appear in the intake and exhaust passages, the inner cavity of the water jacket, and the inner corners of the heat joints. Because the burrs are located in the inner cavity, it is difficult to clean, and the veins in the water jacket cavity Defects will hinder the normal flow of cooling water, and in severe cases, the engine will burn; the veins in the intake and exhaust passages will affect the vortex characteristics of the air passage, and seriously affect the performance of the engine. is crucial. [0003] The root cause of the veining defects on the casting surface is the cracking of the sand mold caused by the expansion of silica sand at 573°C. At a temperature of ...

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Problems solved by technology

[0004] Although the veining defect can be improved by replacing silica sand with pearl sand and the like to inhibit its phase transformation expansion, pearl sand is much more expensive than silica sand, and the casting cost is too high; and the addition of traditional inorganic anti-veining additives is high. The weakening effect of the sand mold strength is large, and the plasticity is small, and the inhibition effect on the phase change expansion cracking of the silica sand mold is small, and the anti-veining effect is not good.

[0005] There is currently no way to overcome the above drawbacks