The quality control standards of zircon sand mainly include the following aspects:

I. Chemical composition

Zirconia dioxide (ZrO) content: ZrO content is generally required to be no less than 63%, and the content of high-quality products can reach more than 65%.

Impurity content: Iron oxide (Fe₂O₃) content should be controlled below 0.1%, titanium oxide (TiO₂) content should not exceed 0.15%, aluminum oxide (Al₂O₃) content should not exceed 0.8%, and silicon dioxide (SiO₂) content should generally be between 32% and 34%.

Radioactive substances: The specific activity of total radionuclides should be controlled below 7× 10μ ci/kg.

II. Physical properties

Particle size distribution: according to different application scenarios, the particle size requirements of zircon sand are different. For example, the particle size of zircon sand for investment casting usually ranges from 80 mesh to 325 mesh.

Density: The density of zircon sand is generally between 4.2 and 4.6 g/cm.

Mohs hardness: usually between 7.0 and 8.0.

Fire resistance: it should reach above 1540℃, and the fire resistance of high-quality products can reach above 1750℃.

III. Other indicators

Magnetic content: the magnetic content should be controlled below 0.01%.

Water content: the water content should not exceed 0.3%.

Loss on ignition: The loss on ignition should be controlled within 0.3%.

Acid consumption value: the number of milliliters of 0.1mol/L hydrochloric acid solution consumed to neutralize alkaline substances in 50g zirconium sand should not exceed 5.

IV. Quality inspection

Ex-factory inspection: each batch of products can only leave the factory after passing the inspection by the factory quality inspection department. The inspection items include ZrO₂ content, particle size distribution, water content and appearance.

Type inspection: Type inspection shall be carried out in the case of changes in raw materials or production processes, resumption of production after long-term suspension of production, and great differences between the results of ex-factory inspection and those of the last type inspection.

V. Packaging and transportation

Packaging: 25kg plastic woven bag or kraft paper bag is usually used for packaging, and large bag packaging can also be carried out according to customer requirements.

Transportation: A 20-foot container can carry 24 tons, and a 40-foot container can carry 28 tons.

Through strict quality control standards, the application performance and stability of zircon sand in precision casting, refractories, ceramics and other fields are ensured.