Relative Physical Constants of Ammonium Paratungstate

Ammonium paratungstate crystals were white and transparent, is a loose and fluidity are better powder material. Ammonium paratungstate English name Ammonium paratungstate, commonly referred to as APT. Ammonium paratungstate for the relevant physical constants, it should include the molecular formula, crystallization temperature, solubility and so on.

Currently in the process of smelting tungsten, the general is the first production of intermediate products ammonium paratungstate. Paratungstic acid is then added Ammonia as a raw material for the follow-up of tungsten powder, tungsten oxide and other tungsten products. Therefore, follow-up production of tungsten products performance, quality and intermediate of ammonium paratungstate physical constant has a great relationship. This relationship is called "heredity." Since the physical constant purity of ammonium paratungstate, such as morphology, particle size and fluidity, has a great influence on the performance of subsequent tungsten products, preparing ammonium paratungstate with good morphology and small particle size is a key step in the tungsten smelting process. This step determines the overall performance of subsequent tungsten products.

Ammonium paratungstate has the formula 5 (NH4) 2O12WO3nH2O (n = 5, 7, 11), correspondingly abbreviated to APT-10, APT-6 and APT-4. In the case of the ammonium paratungstate physical constants, when the paratungstate crystallization temperature is lower than 50C, acicular undecorated water APT can be obtained. When the paratungstate crystallization temperature is higher than 50 ° C, flake pentahydrate APT can be obtained. At the same time in this process may have seven water APT. As ammonium paratungstate in water solubility is small, so its solubility in different temperature aqueous solution is an important factor in the quality of ammonium paratungstate.

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