3362.     ---------------.  [TEICHNER, S.]  [Kieselguhrs of the Type Utilized as Support for Catalysts.]  Jour. chim. phys., vol. 47, 1950, pp. 229-232; Chem. Abs., vol. 44, 1950, p. 7635.

        Following properties of raw kieselguhr, kieselguhr treated with HCl and HNO2 and calcined kieselguhr were determined after different thermal treatments:  Loss in weight after etching in Na2CO3, density, and specific surface as determined by adsorption of N2 and CO at -195 and C4H10 at 0.  The kieselguhr treated with acids had approximately 50% greater specific surface than the raw kieselguhr.  The specific surface of the calcined kieselguhr was only 11% as great as that of the untreated kieselguhr.  Treatment with 5% Na2CO3 reduced slightly the surface area of the raw kieselguhr, but the same treatment decreased by 50% the surface area of the acid-treated kieselguhr.  Presumably the acid treatment caused the formation of siliceous gel, which was soluble in Na2CO3.  Discusses significance of the results to the activity of supports for catalysts used in the Fischer-Tropsch process.