| 摘要 |
A process for the production of stable polycrystalline nickelic oxide comprises contacting an alkaline suspension of nickel hydroxide having a pH of at least 9 with an oxidizing agent having at least sufficient available oxygen to convert substantially all the nickel hydroxide to nickelic oxide and having sufficient oxidation potential to effect reaction, filtering and recovering the insoluble residue of nickelic oxide thus produced and drying the nickelic oxide at a temperature below its decomposition temperature. Two variations of the method are described which lead to distinct nickel oxides. The first is a compound of general formula Ni2Ox.YH2O wherein x is a value of from 2.8 to 3.3, the atoms of the compound being arranged in such a manner that the X-ray diffraction pattern is characterized by at least the following d values 4.68, 2.35 and 1.41, the intensity ratio for each small d value being from 25-40% of the strongest line which falls at a d value of 4.68, the compound being thermally stable at temperatures up to about 90 DEG C. for periods up to 16 hours. This compound is prepared by method A below. The second compound prepared by method B below is of the same general formula in which x has a value from 3.3 to 3.9, the atoms of the compound being arranged in such a manner that the X-ray diffraction pattern is characterized by at least the following d values, 7.11, 3.50, 2.39, 2.12, and 1.41, and the intensity ratio of each smaller d value being from 5 to 17% of the strongest line in the pattern which falls at a d-value of 7.11, the compound being thermally stable at temperatures up to about 90 DEG C. for periods up to 16 hours. Method A comprises (a) forming a reaction product mixture in an aqueous environment by reacting a nickel salt with sodium hydroxide in a molar ratio of about 1 to 2, (b) aging the reaction product mixture for at least 2 hours in said aqueous environment, (c) oxidizing the aged reaction product mixture with sufficient aqueous sodium hypochlorite solution to provide the theoretical amount of available oxygen at a pH of at least 9, (d) recovering the delta nickelic oxide by filtration, (e) washing and drying the recovered nickelic oxide. Method B comprises (a) forming a reaction product mixture by reacting a nickel salt and sodium hydroxide in an aqueous environment at an elevated temperature and a molar ratio of about 1 to 2, (b) aging the reaction product mixture by reacting a nickel salt and sodium hydroxide in an aqueous environment at an elevated temperature and a molar ratio of about 1 to 2, (b) aging the reaction product mixture for at least 2 hours at a pH of about 9, (c) contacting the aged reaction product mixture within an amount of oxidizing agent sufficient to provide at least 500% excess of the theoretical amount of available oxygen at a pH of at least 9, (d) recovering the nickelic oxide thus produced, (e) and washing and drying said nickelic oxide. |
