In the diatomaceous earth filtration method, diatomaceous earth itself has many natural small pores. The irregular pores in the filter layer are longer and densely distributed throughout the entire filter cake layer, which can adsorb and accommodate more fine particles, thereby improving the quality of filtration.

Filtering consists of two parts: sieving and adsorption. In operation, diatomaceous earth is pre coated and adsorbed onto the filter cloth outside the filter, forming an incompressible filter cake layer with countless intricate and intersecting micro pores. During filtration, large impurities in the filtrate are trapped on the outer surface of the filter cake layer due to the inability to pass through relatively small filter holes, which is called the sieving process. Small particles enter the filter cake layer and are adsorbed and trapped in the curved and intricate pores, which is called the adsorption process. Thus obtaining a clear permeate solution. When the filtration pressure of the filter increases, it indicates that some of the filter holes in the filter layer have been blocked. At this time, a new filter layer is formed by adding diatomaceous earth into the filter to continue the filtration. When most of the pores in the filter cake layer are blocked and the filtration rate decreases, the filter cake is removed and a new filter cake layer is pre coated before filtration. When observing the filtration of filter cake divided into pre coating and filter layer, it can be found that most impurities are filtered out by sieving and trapped outside the filter holes, with few impurities adsorbed inside the filter holes.