APT Crystallization Liquor Treatment -- Hydrochloric Acid Adjustment
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, S2- is generated to H2S 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 Ca, Mg, Cu form into a precipitate. A small amount of impurities that did not form a precipitate were mixed into the peak ammonium tungstate solution as the crystallization liquor was formulated as a desorbent, in the subsequent molybdenum removal process, the removal of the molybdenum reagent is carried out.
The starting point of this method is the recycle of tungsten and ammonium chloride in the APT crystallization liquor, but the liquor in the high concentration of S2- not only can damage the ion exchange resin, can also lead to resolve the peak concentration of S2- on the high side, eventually the final crystallization of the APT sulfur exceeded. Therefore, a more appropriate treatment process is taking out a sulfur removal treatment. Hydrochloric acid adjustment method, while the cost is low, the process is short, but after all, the main material acids chemicals will inevitably increase the cost of environmental protection, so it needs to think twice before using it.
If you have any inquiry of tungsten oxide, please feel free to contact us:
Tel.: +86 592 5129696 +86 592 5129595
Fax: +86 592 5129797
评论
发表评论