Ammonium Paratungstate Crystallization Mother Liquor Treatment--Conversion Method

From dressing industrial progress of history suggests that mineral processing reagents application significance is self-evident. 
Since its discovery in 1924 xanthate has the function of collecting sulfide ore, the development of the flotation industry started by leaps and bounds, the inundated mineral processing reagents has been invented and created with a steady stream.
Ammonium Paratungstate Crystallization Mother Liquor Treatment image
The crystallization crystallization method and the neutralization method produce the crystallization mother liquor in the preparation of APT. These mother liquor contain not only impurities but also some WO3.
In order to improve the total recovery of tungsten, the mother liquor is often recovered once again in the industry treatment, as to which method should be based on the previous process and the composition of the mother liquor to use, usually available alternative methods are conversion method, solution extraction and ion exchange method.
Conversion method is commonly used in the crystallization process of ammonium paratungstate crystallization mother liquor, it is added to the crystallization of the mother liquor NaOH, turn tungsten into Na2WO4 solution, and then according to the mainstream process to determine the craft.
The presence of tungsten in the mother liquor with polyacid and heteropoly acid can be converted to sodium tungstate, the solution after heating need to boil, volatilize the ammonia.
The main process for acid decomposition--ammonia crystallization process, the crystallization of the mother liquor by alkali conversion, should be concentrated to WO3 content of 150g / L, and then by the classical chemical method for precipitation, precipitation of artificial white tungsten, and then the artificial white tungsten and scheelite mixed into the mainstream craft for processing.
Mainstream program for classic precipitation purification craft or extraction craft, the crystal mother liquor after alkali into the crude sodium tungstate solution, can be added directly after purification in the recovery of tungsten.
Main process of ion exchange craft, and its crystallization mother liquor after transformation, no longer suitable for the original ion exchange craft, it needs to be deposited artificial scheelite classic precipitation or extraction.
In APT crystal mother liquor processing technology is more in our country at present, have their own characteristics, but cannot leave the essence of removing impurity and recycling. Reforming process is suitable for the classic craft, but with the improvement of tungsten smelting technology, classic technology has been gradually withdraw from the historical stage, so the process is more like a role of relay station.