High Purity Ammonium Paratungstate Ion Exchange Method (1)

Tungsten, a refractory non-ferrous metal, is also an important strategic resource that has been widely used due to its excellent properties such as high melting point, high hardness, ductility, wear resistance and corrosion resistance. Ammonium paratungstate is an important tungsten primary product , its quality directly affects the quality of tungsten deep processing products. High purity ammonium paratungstate refers to ammonium paratungstate in which the total amount of impurities can be controlled within 70 ppm, that is, ammonium paratungstate with a low impurity content.

Ammonium paratungstate produced by the existing ion exchange method only meets the national standard of zero level and can not satisfy the need of deep processing of tungsten products. Therefore, some scholars have provided an improved process of ion exchange method, During the purification of ammonium paratungstate, the single column ion exchange can be saturated fed by improving the adsorption, and the selective column ion exchange adsorption is used to improve the purification efficiency of ion exchange.

(1) The tungsten mineral is placed in a ball mill silo, and the tungsten mineral is fed into a vibrating ball mill through the quantitative and constant speed of a screw feeder, ball milling is performed by adding an appropriate amount of phosphorus salt and water, and the slurry is adjusted to a certain volume reactor, the alkali boiled decomposition.

(2) The reactor is heated, the alkali decomposition temperature is controlled at about 120 ℃ -180 ℃; 0.5-1.1Kgf / cm² pressure, incubated for 1.5-2 hours, into the prior to add water and a certain amount of trisodium phosphate dilution barrel within the dilution.

(3) Diluting the barrel with water diluted to 2-6 times the original volume, the diluted liquid into the filter press filter, washing, after a filter press the crude sodium tungstate solution and the decomposition of the filter residue separation, a filter press out of the crude sodium tungstate solution and then the second filter press, the second filter press solution for the secondary filter press of crude sodium tungstate solution, followed by three times the filter press, after three times pressure filtration, the three sodium tungstate solution obtained by filter pressure reached the supernatant of the filter, that is, the crude sodium tungstate solution.

Read more: High Purity Ammonium Paratungstate Ion Exchange Method (2)

http://news.chinatungsten.com/en/tungsten-information/103458-ti-13083

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