| abstract |
The method of obtaining high purity nanocrystalline nickel (II) tungstate by mixing aqueous soluble solutions of tungsten (VI) and nickel (II) salts is characterized in that for an aqueous solution of tungsten (VI) salt containing above 5 g / dm3 W, preferably 30 g / dm3 W, a solution close to saturation of dissolved nickel (II) salt, preferably acetate, in such an amount that in the resulting mixture the molar ratio of nickel to tungsten is greater than 1.5 and less than 15, preferably 2, the whole is stirred at a temperature above 40 ° C, within 30 to 240 minutes, preferably 90 minutes, so that the pH of the mixture is in the range of 6.0 to 9.5, preferably 7.0 - 7.7, and the pH is adjusted using 5 - 15% aqueous solutions of ammonia and / or sodium hydroxide, and the precipitate thus separated is subjected to a purification process and then drying. |