Three spent com. Ni catalysts from methanization and reforming processes were leached with aq. HNO(3), H(2)SO(4) or HCl soins. at 80 degrees C or 95 for 8 h to recover Ni under tab. conditions. In the case of reforming catalysts sintered at high temp. during operation, the Ni recovery was insufficient. Therefore, the leached catalysts were addnl. hydrogenated at 700-800 degrees C and leached once again with aq. HNO(3) soln. The leachetes were partly neutralized with NaHCO(3) to pH 3 to ppt. Al and Fe hydroxides filtered, twice extd. with Porg. agent-contg. naphtha to remove Ca and Mg ions, and then treated with Na(2)CO(3) to ppt. NiCO(3)center dot Ni(OH)(2)center dot 2H(2)O. The ppt. was dissolved in HNO(3) soln. to sep. cryst. Ni(NO(3))(2). The Ni recovery degree was 72-91%.