Process for reacting a zirconia based material
AssigneeAtomic Energy Corporation of South Africa Limited
InventorJohannes Theodorus Nel
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Abstract
A process for reacting a zirconia-based material comprises reacting, in a reaction step, plasma dissociated zircon with aqueous hydrogen fluoride to produce a soluble fluoro zirconic acid compound.
Claims13
A process for reacting a zirconia-based material which process comprises reacting, In a reaction step, plasma dissociated zircon with aqueous hydrogen fluoride, with the quantity of hydrogen fluoride, as aqueous hydrogen fluoride, used being such that the molar ratio of hydrogen fluoride to zirconia present in the plasma dissociated zircon is between 1.1:0.9 to 0.9:1.1 to produce a soluble fluoro zirconic acid compound.
A process for reacting a zirconia-based material, which process comprises
- reacting, in a reaction step, non-desilicated or partially desilicated plasma dissociated zircon with aqueous hydrogen fluoride, to produce a soluble fluoro zirconic acid compound, as well as soluble fluoro silicic acid compound;
- separating a liquid fraction comprising residual aqueous hydrogen fluoride, the soluble fluoro zirconic acid compound and the soluble fluoro silicic acid compound, from a residual solids fraction comprising poorly soluble or insoluble impurities selected from the group consisting in U, Th, Fe, Ti, Al and Ca;
- heating the liquid fraction to evaporate the soluble fluoro silicic acid compound and aqueous hydrogen fluoride so that the fluoro zirconic acid compound remains as a purified solid fraction.
A process according to 9, which includes further purifying the fluoro zirconic acid compound which remains as the purified solid fraction, by means of redissolving, recrystallization or ion exchange, and converting the purified fluoro zirconic acid compound to zirconia by means of steam pyrolysis.
Dependencies are inferred from the claim text.