PATENTS

3150.----- [RUHRCHEMIE, A. G.]  [Production of Kieselguhr Suitable for Carrier for Hydrogenation Catalyst.]  German Patent Apppl. R 103,980, PA 967,306, filed Dec. 6, 1938 (Cl. 12 o-1.03).  FIAT Reel B-196, frames 411-414; PB 83,253; PB report 412, May 15, 1945.

Kieselguhr to be used as synthesis catalyst support is treated with a relatively volatile acid such as HCl or HNO₃ to remove inorganic impurities and is then oxidized below the sintering temperature to remove organic matter and the remaining traces of acids.  Alternatively the metals may be removed as bicarbonates by blowing CO₂ through a suspension of kieselguhr, after which the kieselguhr is washed, dried, and calcined 1 hr. at 550° C.