| 摘要 |
PCT No. PCT/US97/03221 Sec. 371 Date Jul. 29, 1998 Sec. 102(e) Date Jul. 29, 1998 PCT Filed Feb. 28, 1997 PCT Pub. No. WO97/31860 PCT Pub. Date Sep. 4, 1997A method of separating calcium from mixtures of metal oxides, sulfides, nitrates and carbonates. Particulate calcium containing mixtures are leached with nitric acid to form calcium nitrate and metal nitrates, which are heated to dryness and to form metal oxides, while not affecting the calcium nitrate. The resulting mixture is then leached with water to obtain a calcium nitrate containing leachate and a residue of low solubility metal oxides and insoluble metal oxides. If desired, the calcium nitrate can be decomposed to form a lime product.
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