Diatomite filter aids can be divided into dry algae products, calcined products and flux calcined products according to different production processes.

 ① Dried products
After purification, pre drying and comminution, the raw material is dried at 600-800 ° C, and then comminuted. This kind of product has very fine particle size and is suitable for precision filtration. It is often used in combination with other filter aids. The dry products are mostly light yellow, but also milky white and light gray.

② Calcined products
The purified, dried and crushed diatomite is fed into a rotary kiln, calcined at 800-1200 ° C, then crushed and graded to obtain the calcined product. Compared with dry products, the permeability of calcined products is more than three times higher. Calcined products are mostly light red.

 ③ Flux calcined products
After purification, drying and grinding, the raw material of diatomite is added with a small amount of sodium carbonate, sodium chloride and other melting AIDS, and calcined at 900 ~ 1200 ° C. after grinding and particle size grading, the flux calcined product is obtained. The permeability of flux calcined product is obviously increased, which is more than 20 times of that of dry product. The flux calcined products are mostly white, and light pink when the content of Fe2O3 is high or the amount of flux is small.