PATENTS

3135.----- [RUHRCHEMIE, A. G.]  [Process for Recovering Thorium for Catalyst Manufacture from Iron-Thoruim Slurries Occurring in Working-up Spent Catalysts for Hydrogenatio of Carbon Monoxide.]  German Patent Appl. --, 725, filed Sept. 125, 1944.  FIAT Reel K-30, frames 7,745-7,748; PB 73,587; TOM Reel 37, bag 3,451,, item 36, 4 pp.; Meyer Transl. PC-S-II, Fischer-Tropsch, vol. 4, chap. 129, 1949, p. 11.

Slurries are treated with alkali bicarbonates or substances forming these or with mixtures of the same with alkali carbonates.  The thoria is separated from the solution by neutralization with acids, or use may be pressure and whatever temperature desired.  The CO₂ is set free by expanding the solution freed of thoria, whereupon the CO₂ and the soda solution resulting thereby are returned to the process.  The solution obtained from the Fe-Th slurry, if desired after cutting back with suitable amounts of soda solution of proper concentration, is employed directly for the preparation of catalysts.