The bulk density of Molai sand is one of its important physical properties, and it is usually required that the bulk density is ≥ 2.5 g/cm. The bulk density has many influences on the application of Molaisha:

I. Fire resistance

High-temperature stability: Higher bulk density means that Moray sand has a tighter microstructure, which can maintain better stability at high temperature and reduce deformation and erosion at high temperature.

Refractory: Molai sand with high bulk density usually has higher refractoriness, generally above 1750℃, which makes it suitable for high temperature casting and refractory fields.

II. Castability

Strength of mould shell: Molaisha is used to make the surface and back layer of mould shell in precision casting. Molai sand with high bulk density can form a more compact mold shell, which improves the strength and corrosion resistance of the mold shell.

Casting quality: Molai sand with high volume density is helpful to reduce the porosity and defects on the casting surface and improve the smoothness and accuracy of the casting.

Demoulding performance: the shell made of high-density Moray sand is easier to demould after pouring and is not easy to deform.

III. Thermal expansion performance

Low expansion coefficient: Molaisha has a small thermal expansion coefficient, and the high bulk density further enhances this characteristic, making it difficult to deform at high temperature and ensuring the dimensional stability of the mold shell.

IV. Thermal insulation performance

Lightweight and thermal insulation: In some applications, such as lightweight mullite thermal insulation materials, lower bulk density (such as 0.4-1.5 g/cm) is helpful to achieve better thermal insulation effect. However, for application scenarios that require high strength and high fire resistance, high bulk density is still the first choice.

V. Application areas

Precision casting: Molybdenum sand with high bulk density is widely used in precision casting fields such as stainless steel and alloy steel, and is used to make the surface layer and back layer of mold shell.

Refractory material: high-density mullite sand can be used to make high-temperature furnace lining, refractory brick, etc., with good corrosion resistance and high-temperature strength.

Thermal insulation materials: Molaisha can also be used to prepare lightweight thermal insulation materials by controlling the bulk density.

VI. Summary

The bulk density of Molai sand has an important influence on its fire resistance, casting performance and thermal expansion performance. Molaisha with high bulk density is suitable for high temperature and high strength application scenarios, while low bulk density can be used for light thermal insulation materials. According to the specific application requirements, choosing the appropriate bulk density is the key to ensure the performance of Moraine sand.