1. Sieving action
This is a surface filter function. When the fluid flows through the diatomite, the pore size of the diatomite is lower than the particle size of the impurity particles, so that the impurity particles cannot pass through and are retained. This function is called screening.
In essence, the surface of filter cake can be regarded as a screen surface with equivalent average aperture. When the diameter of liquid particles is not less than (or slightly less than) the pore diameter of diatomite, liquid particles will “screen” out of the suspension, playing the role of surface filter.
2. Depth effect
Depth effect is the retention effect of deep filter. In the deep filter, the separation process only occurs again in the “interior” of the medium. Some of the smaller impurity particles passing through the surface of the filter cake are blocked by the zigzag microporous channels inside the diatomite and the finer pores inside the filter cake. Such particles are often lower than the microporous pores of the diatomite. When the particles hit the inner wall of the channel, it is possible to collapse the liquid flow, but whether it can achieve this, It is required to balance the inertia force and resistance that the particles are subjected to. This interception and screening action are similar in nature and belong to mechanical action. The ability of filtering liquid particles is basically related to the comparative size and shape of liquid particles and pores.
The mechanism of adsorption is quite different from that of the above two filters. In essence, this effect can also be regarded as electrokinetic attraction, which mainly depends on the surface properties of liquid particles and diatomite itself. When the particles with small pores in the diatomite hit the internal surface of the porous diatomite, they are attracted by the opposite charge. Another is that the particles attract each other to form chains and adhere to the diatomite. These are all attributed to adsorption.
Application of diatomite in
1. Diatomite is a high-quality filter aid and adsorbent material, which is widely used in food, medicine, sewage treatment and other fields, such as beer filter, plasma filter, drinking water purification, etc.
2. Make cosmetics, facial mask, etc. Diatomaceous earth facial mask uses the conductivity of diatomaceous earth to conduct impurities in the skin, playing the role of deep care and whitening. People in some countries also often use it to cover the whole body for body beauty, which plays a role in skin care.
3. Disposal of nuclear waste.
Post time: Oct-31-2022