| 摘要 |
The invention relates to a process for preparing metal nitrates from the corresponding metal wherein the metal is selected from silver, cadmium, bismuth and the metals of atomic number 24 - 30. The process comprises (A) providing a reactor containing (a) the metal, (b) nitric acid, and (c) water wherein the initial concentration of the nitric acid in the water in the reactor is from about 50% to about 80% by weight, and the reactor is free of (1) added fuming nitric acid, (2) added chromium compounds when the metal is iron, and (3) added oxygen, and when the metal is nickel the reactor contains less than 500 g/l of any added nickel nitrate hexahydrate, and (B) maintaining the temperature within the reactor at a temperature to facilitate the formation of the metal nitrate and to maintain the produced metal nitrate in the molten state; (C) maintaining the pressure within the reactor at between atmospheric pressure up to about 100 psig; and (D) recovering the metal nitrate from the reactor, provided that when the metal is iron, any recovered iron nitrate is not recycled. The process of the present Invention results in the formation of metal nitrates and more particularly aqueous solutions of metal nitrates containing reduced amounts of ammonium nitrate.
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