3268980

9715

Diatomite filter aids were prepared using raw diatomite and various fluxes. The effects of composition, amount and granularity of the flux on the micro-structure and filtration performance of the diatomite filter aids were studied. Filter aids with high flow rate and filtrate clarity were successfully obtained when 7 wt. % of Na2CO3 flux was employed. It was shown that opal in the diatomite was converted to cristobalite in the presence of flux at 1000 °C, being similar to the formative process of silicate glass. The additive alkali ions from the flux are believed to partially break SiOSi chains of the opal at a high temperature and then recombine the broken structure to a hexatomic ring mesh structure during the cooling process, which is significative to control the phase composition for preparation of diatomite filter aids.

28

Diatomite , Filter aids , flux , structure , Filtration property

Studia Iranica

33

33