Diatomite mineral properties

Diatomite is a biogenic siliceous sedimentary rock, which is mainly composed of ancient diatom remains. Its chemical composition is mainly SiO2, containing a small amount of Al2O3, Fe2O3, Cao, MgO, K2O, Na2O, P2O5 and organic matter. SiO2 usually accounts for more than 80%, up to 94%. The iron oxide content of high-quality diatomite is generally 11.5%, and the alumina content is 36%. The mineral composition of diatomite is mainly Opal and its variants, followed by clay minerals hydromica, kaolinite and mineral debris. Mineral fragments include quartz, feldspar, biotite and organic matter. The content of organic matter ranges from trace to more than 30%.

The color of diatomite is white, grayish white, gray and light grayish brown, with fine, loose, light, porous, strong water absorption and permeability.

Diatoms in diatomite have many different shapes, such as disc, needle, tube, feather and so on. The loose density is 0.3-0.5g/cm3, the Mohs hardness is 11.5 (diatom bone particles are 4.5-5mm), the porosity is 80-90%, and it can absorb water 1.5-4 times its own weight. It is a poor conductor of heat, electricity and sound. The melting point is 1650-1750c, with high chemical stability. It is insoluble in any strong acid but soluble in strong alkali solution.

The silica of diatomite is mostly amorphous, and the content of soluble silicic acid in alkali is 5080%. Amorphous SiO2 becomes crystalline when heated to 8001000c, and the soluble silicic acid in alkali can be reduced to 2030%.

Market status

Utilization of environmental protection wall material diatomite

At present, diatomite decoration materials in the building materials market mainly fall into three categories: one is natural dry products containing impure substances, which are cheap. The other is ordinary kiln fired products. It is first made of diatomite into plates and bricks of various shapes, and then fired at a high temperature of 800 ℃. It is a bit like ceramic tile, and the price is general. The third category is kiln fired products with various additives. This kind of high-grade products added with special materials use high-quality diatomite and add additives such as salt, soda ash or photocatalyst to remove impure organic matter, carbon and other substances in a kiln with a high temperature of about 1100 ℃, and burn them into various high-grade and gorgeous diatomite room decoration materials. Diatomite decoration materials sold on the market mainly include wall materials (plates), flooring materials, sanitary ware, ceiling materials, etc.

Diatomite wall materials can effectively remove free formaldehyde, benzene, ammonia, VOC and other harmful substances in the air, as well as the peculiar smell generated by pet body odor, smoking and domestic garbage, comprehensively solve indoor air pollution and significantly improve the indoor living environment.