Ammonia at Room Temperature Dissolved Ammonium Paratungstate Recycle

At present, some manufacturers in order to reduce the cost, improve the recycle rate of tungsten smelting, substandard ammonium paratungstate recycle as seeds to melted down, we can get rid of unqualified products while at the same time does not increase the cost, but after doping products for the quality of hard alloy production of tungsten powder, tungsten carbide and tungsten will affect the order of products. Some manufacturers directly dissolve unqualified products with strong alkali to turn them into sodium tungstate solution and return to the production of ammonium paratungstate, but this method is very expensive.

For this reason, some scholars have proposed a method of dissolving ammonium paratungstate or tungsten oxide with ammonia water at normal temperature and atmospheric pressure. The method comprises the following steps: mixing ammonium partrungstate (or tungsten oxide) with ammonia water, and obtaining a mixture; stirring the obtained mixture and heating up, and obtaining ammonium containing ammonium tungstate solution.

The reaction equation of ammonium parotungstate by ammonia water is as follows:

5(NH₄)₂·O·12WO₃·5H₂O+14NH₃·H₂O=12(NH₄)2WO₄+12H₂O

The reaction equation for the dissolution of tungsten oxide by ammonia water is as follows:

WO₃+2NH₃·H₂O=(NH₄)₂WO₄+H₂O

100g ammonium tritulfide clear tank material and 120mL 25% ammonia water and 150mL pure water were mixed and stirred at 400rpm rotational speed in a sealed reactor. The temperature increased to 100 degrees Celsius and kept for 3 hours. After the reaction was finished, the 265mL ammonium tungstate solution was obtained by cooling and filtration. All the cleaning materials were dissolved and the dissolution rate was 100%.

This low temperature and low pressure ammonia solution of ammonium paratungstate and tungsten oxide completely dissolved, adaptable, not only to deal with ammonium paratungstate and tungsten oxide waste, but also can be processed after oxidation of tungsten powder, tungsten carbide and tungsten carbide production waste, the finished product ensured the quality and controlled the cost.

Some scholars have proposed a method to dissolve ammonium tungstate or tungsten oxide at room temperature and atmospheric pressure by ammonia water, the method is to mix ammonium paratungstate (or tungsten oxide) with ammonia water, and get the mixture, the mixture is stirred and heated up to obtain ammonium containing ammonium tungstate solution.

• < Prev
• Next >