Solid/liquid separation other filter aids

Pulverised fuel ash, sawdust, spent lime and many other waste products can and have been used in some apphcations usually where a rou separation is required. Other eciahy prepared solid powder materials such as hydrated magneaum silicate, hydrated calcium silicate, bentonite, fuller s earth, or activated carbon are used in some applications piinc ally because of their adsorptive properties but they may also act as a filter aid in the separation of the particulate solids fi om the liquid. 

This procedure is intended to result in separation of the free" liquid portion of the waste from any solid matter having a particle size > 0.45p.m. If the sample will not filter, various other separation techniques can be used to aid in the filtration. As described above, pressure filtration is employed to speed up the filtration process. 

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