Quality Test of Rice Hull Ash Filter Aids

Rice hull ash (RHA) is produced from the combustion of rice hulls for energy generation and steam processes. This product is an excellent filter aid quantified by the very good physical, chemical as well as filtration properties, such as fine, porous, rigid, easily dispersed and suspended, and chemically inert. Quality of the filter aid is determined by its physical and chemical properties, and is reflected by its filtration performance, which is evaluated by cake permeability, filtrate clarity, solid rejection rate, wt% of cake solids in filter aid precoat filtration, and filtration of solid-liquid suspensions with filter aids as a body feed. Standard methods of testing filter aids quality include pH, particle size, bulk density, permeability, solid rejection rate, and moisture of cake. Test results of different grades of RHA filter aids are presented.