Coarse crystal ammonium paratungstate has found wider applications in many fields with the continuous development of new tungsten carbides and filament types. Therefore, it is of significance to study the preparation process of APT.
Preparation of Coarse Crystal Ammonium Paratungstate
At a water bath temperature of 60°C and under a certain degree of vacuum, a certain concentration of 300mL AT solution was poured into a 500mL 3-neck flask, stirred to evaporate to precipitate milky crystal nucleus, and heated within 1/2h to evaporation temperature of main phase. At the same time, continuously adjust the pH value of the solution in a certain range by pouring this concentration of AT solution through the separatory funnel into the bottle. The vacuum evaporation time of main phase is 8h, cooling to 50°C, vacuum filtration, washing precipitate with 20mL 1% NH4NO3, drained, washing with 10mL distilled water, drained again, and finally the product was placed in a constant temperature drying oven at 100°C for 3h to the coarse crystal APT.
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