Tungsten Oxide

The crystalization method of evaporation and extraction method in the preparation of APT will produce crystallization liquor, leaving about 5% -10% of the WO3 and part of the S, P, As, Mo, K, Na and other impurities. Resulting in it can not directly return to the process of use , In order to improve the recycle of metal , it is necessary to set up auxiliary processes to recycle WO3 in the liquor. Hydrochloric acid adjustment method is a new occurrence of ammonium paratungstate crystallization liquor treatment process, it low cost, short process, and the equipment is simple. Hydrochloric acid method is mainly by using the reaction of strong acid against weak acid, adding suitable amount of hydrochloric acid into APT crystallization liquor, S 2-  is generated to H 2 S and volatilize from the liquor, tungsten is precipitated in the form of tungstic acid. Other few phosphorus, arsenic, tin and some impurities with most of cations like ...