A kind of spinel foundry sand and preparation method thereof

Abstract

The invention discloses magnesium-aluminum spinel casting sand prepared by sintering bauxite raw material and industrial magnesium oxide and a preparation process of the magnesium-aluminum spinel casting sand. The magnesium-aluminum spinel casting sand comprises the following main raw materials: 72.9% of bauxite raw material, 98% of magnesium oxide and the like. The preparation process comprises the following steps: weighing bauxite and industrial magnesium oxide powder according to a stoichiometric ratio, adding an appropriate amount of binders, mixing the materials, performing wet grinding, drying, pelletizing in a pelletizing machine, finally putting into a silicon molybdenum rod box type furnace for sintering and performing heat preservation at 1,550 DEG C for 5 h, cooling with the furnace, and then screening to obtain the magnesium-aluminum spinel casting sand. The novel spherical sand prepared by the preparation process disclosed by the invention has the characteristics of high temperature resistance, high strength, low thermal expansion rate, good anti-sticking sand performance, good recycling performance, low production cost and environmental friendliness; in the application aspect, the magnesium-aluminum spinel casting sand is suitable for molding methods of water glass, resin, bentonite and the like, and is suitable for precision casting, expendable pattern casting, V process casting and polishing treatment of nonferrous metals.

Description

[0001] Technical field: [0002] The invention relates to a method for preparing a novel artificial spherical casting sand, in particular to a high-performance spherical sand prepared by using bauxite and industrial magnesium oxide and a production process thereof. [0003] Background technique: [0004] Traditional foundry sand has low refractoriness and large thermal expansion, which affect the quality of castings. Non-quartz raw sand has the advantages of high refractoriness and low expansion coefficient, but its scarce resources and high price increase the cost of castings. It is easy to chemically react with metal liquids of certain special components, causing casting defects. limitation. Artificial spherical sand for foundry has the advantages of high refractoriness, small thermal expansion, good reusability, etc. It has been well used in thick and large parts, steel castings, sand core production and coated sand, and the amount is increasing year by year. [0005] Spherical sa...

AI Technical Summary

Problems solved by technology

[0006] At present, the following problems exist in the use of artificial spherical sand in my country: 1. The variety and system of spherical sand are single, and the serialization and commercialization of spherical sand in practical applications are relatively low

2. Traditional production is prepared by arc melting method, which consumes a lot of energy, which is not conducive to improving energy efficiency and building an energy-saving society in my country

3. Spherical sand is mainly concentrated in aluminum-silicon series spherical sand, and the refractoriness is still not ideal

4. The chemical composition is messy, and the high temperature slag resistance is low

5. There is no sintering ability at high temperature, and there is a problem of permeable sand sticking

6. Low mechanical properties at high temperature

7. Low strength and easy to break