GB1170520A - Production of Nickel-Thoria Powders - Google Patents

Abstract

1,170,520. Producing Ni-ThO 2 powders. SHERRITT GORDON MINES Ltd. Nov. 10, 1967 [Nov.30, 1966], No. 51349/67. Heading C7D. Nickel-thoria powders, in which the ThO 2 particles are of sub-micron size and integrally associated with the Ni particles, are formed by forming a suspension (e.g. in water or alcohol) of particles with a Fischer number less than 5 and comprising 0À5-100% of one or more of basic Ni compounds, NiCO 3 and NiO, the balance being elemental Ni, adding an aqueous solution of Th (NO 3 ) 4 to precipitate a Th compound on the surface of the particles, reducing the Ni compound to Ni (e.g. by H 2 in the presence of anthroquinone as a catalyst) and then dry-heating the reduced particles to decompose the Th compound to ThO 2 while not oxidizing the elemental Ni (e.g. at 540-1100‹ C). The suspending liquid may contain compatible ions (e.g. formate, carbonate or acetate depending on the anion of the suspended material) or a complexing agent for Ni (e. g. NH 3 ) may be added, to solubilize a portion of the Ni content of the suspended particles. The basic Ni compounds may be produced by heating an aqueous solution of a Ni compound (e.g. a Ni ammine carbonate solution formed by leaching Ni, NiO or NiCO 3 in an ammoniacal (NH 4 ) 2 (O 3 solution) to precipitate the finely divided compound. The powders are suitable for the production of wrought dispersion hardened Ni or Ni base alloys by powder metallurgy.