[Filtering active clay method] Clay filter or bag filter is generally used.

[Working principle] Filter pump will be filtrate into the tank through the liquid inlet pipe, and full, under the action of pressure, the solid impurities in the filtrate are intercepted by the filter screen on the filtrate, and the filter cake is formed on the filter screen, filtrate through the filter nozzle into the liquid outlet pipe outflow tank, so as to get clear filtrate. With the increase of filtering time, more and more solid impurities trapped on the filter, the filter cake thickness increases, so the filtering resistance increases, the tank pressure increases, when the pressure rises to a certain value to discharge, stop to fill in input to filtrate and to pass through the overflow pipe blowing compressed air into the tank, the tank will be waiting to filtrate pressure into other containers, and dry cake. Close the compressed air, open the butterfly valve, and start the vibrator to make the filter blade vibrate. The filter cake on the filter screen vibrates down and is discharged through the slag discharge mouth below the tank body.

[Active clay] is an adsorbent made of clay (mainly bentonite) as raw material, after inorganic acidification treatment, and then rinsed and dried by water. It looks like milky white powder with strong adsorption performance and can absorb colored substances. Easy to absorb moisture in the air, placed too long will reduce the adsorption performance. Use appropriate heating (80-100 degrees is appropriate) to revive, but heating to 300 degrees Celsius or more will begin to lose crystal water, so that the structure changes, affecting the fading effect. Active clay is insoluble in water, solvents and various oils, almost soluble in hot caustic soda and hydrochloric acid, the relative density of 2.3 ~ 2.5, in water and oil swelling small.