DIATOMACEOUS EARTH TREATED WITH POLY-ELECTROLYTE PRODUCT AND A NEW PROCESS FOR PRODUCING IT

摘要

1,251,516. Diatomaceous earth. KIESELGUHR DE MEXICO S.A. 30 Oct., 1968 [30 Oct., 1967], No. 51530/68. Heading C1A. A diatomaceous earth with an oil absorbency of 230 gm. of oil per 100 gm. of earth claimed per se is prepared by purifying a diatomaceous earth by contacting it with a polyelectrolyte. Suitable polyelectrolytes include polysaccharids, polyarylamides, acrylamide polymer hydrolytes, carboxymethyl celluloses, guar gums and alginates. Preferably 5 to 1000 parts by weight of polyelectrolyte are used per million parts of earth and the earth should have a moisture content of at least 5% during the treatment. The polyelectrolyte may be in aqueous solution at a concentration less than 0À05% by wt. and the earth preferably has a diatom content of at least 8% by wt. After the treatment, the earth is calcined at 950 to 1500‹ C. In the embodiment shown in Fig. 1, raw diatomaceous earth is fed to a hammer mill 1 and then to a dryer 2. After drying the material is fed to hammer mill 3. The mater al is then classified and fed to the polyelectrolyte reactor 7. The treated material is fed to a hammer mill 8, a calciner 9, rotary cooler 10, hammer mill 11 and air classifier 12 respectively.