3088.----- [RUHRCHEMIE, A. G.] [Process for Removing Calcium From Cobalt Solutions.] German Patent 683,691, R 403, Sept. 19, 1938. TOM Reel 37, bag 3,451, item 35, 3 pp.’ Meyer Transl. PC-S-II, Fischer-Tropsch, vol. 4, ch. 133, 1949, p. 19.

In removing Ca from Co solutions by precipitating the Ca as CaF₂, the solutions are treated with soluble fluorides in the presence of Mg salts. The Co-mg solution is acidified, suitably up to a pH of 2-4, before the addition of a soluble fluoride. In removing the Ca from Co solutions, which also contain Fe and Al salts, the Fe and the Al are first precipitated by means of alkali carbonate solutions, whereupon, after addition of Mg salt, the Ca is precipitated by means of a soluble fluoride.