BENEFICIATION OF DIATOMITES BY HIGH-GRADIENT MAGNETIC SEPARATION

High gradient magnetic separation (HGMS) tests have been carried out t o remove magnetic impurities from a slurry of diatomites from differen t deposits in Bulgaria. It has been found that at magnetic fields grea ter than 0.5 T, the magnetic separator achieves very high removal of m agnetic impurities. The experimental investigations show that the reco very and the grade of the products depend on the source of the raw mat erial. Preliminary studies for preparing specimens of synthetic calciu m silicate hydrates have been carried out as well. The hydrothermal re action of HGMS-processed diatomite, hydrated line and water can produc e high quality calcium silicate hydrates.