Comparition among Diatomaceous Earth Filter Aid, Perlite Filteraid, and Cellulose Filter Aids

1. Diatomaceous earth filter aid

Compared to perlite and cellulose, diatomaceous earth filter aids have a unique rigid and porous structure that can filter out extremely fine solids like a   sieve, while particles can flow freely. Diatomaceous earth filter aids are mainly composed of silica, so DE is inert in a wide range of applications.

Perlite has a certain degree of toughness and elasticity, and is lightweight. The special advantage of perlite as a filtering medium is that it can retain solids while maintaining a high liquid flow rate. Due to its excellent chemical stability and the absence of potential pollutants, its heavy metal ion content is only 0.005%. Due to its advantages of being sterile, odorless, and tasteless, this product can be used for food grade filtration.

3. Cellulose - This material is less commonly used due to its high cost and low filtration efficiency, making it less commonly used than diatomaceous earth   and perlite. However, compared to diatomaceous earth or perlite, it does have some advantages. Cellulose has combustibility, which helps recover soluble metals. Unlike diatomaceous earth and perlite, cellulose can also be compatible with hot corrosive solutions.

Each type of filter aid has a different particle size grade, typically ranging from 5 µ m to 100 µ m. As the particle size decreases, the ability to capture small solids increases, thereby improving the transparency of the filtrate. However, the smaller the particle size, the greater the resistance of the filter cake. Therefore, the finer the filter aid, the lower the throughput per unit area. These relationships require finding an appropriate balance between filtrate purity and   filtration rate. It is important to use the highest possible level of filter aid to achieve the target filtrate clarity.