Tungsten Oxide

The crystalization method of evaporation and extraction method in the preparation of APT crystallization liquor treatment.  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, in order to improve the  recycle of metal, it is necessary to set up auxiliary processes to recycle WO3 in the liquor. The residual alkali decomposition method is characterized by the use of tungsten concentrate decomposition of sodium tungstate in the process of recycle of residual NaOH solution with the liquor reaction, turn the WO 3  directly into Na 2 WO 4  solution, after remove the molybdenum solution into the main purification process and deal with Na 2 WO 4 , and also remove the phosphorus, arsenic, tin and other impurities, the transformation equation is: 2NaOH +(NH 4 ）2WO 4 ===Na 2 WO 4 + 2NH 4 OH 2NaOH +(NH 4 )2MoO 4 ===Na 2 MoO 4 +2NH 4 OH The solution recycled by the residual alka

The crystalization method of evaporation and extraction method in the preparation of APT will produce crystallization liquor, leaving about 5% -10% of the WO 3  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 metal recycle, it is necessary to set up auxiliary processes to recycle WO 3  in the liquor. To contain large amounts of NH 4 Cl crystallization liquor of ammonium paratungstate , ion exchange method can be used to recycle tungsten concentrate and transformed into Na 2 WO 4  and return to the main process. Ammonium paratungstate crystallization liquor treatment of ion exchange need to adjust the pH value of hydrochloric acid to 3-4, through the weak alkaline anion exchange resin layer, where the tungsten, molybdenum and impurity phosphorus, arsenic, silicon with the same polyacid or heteropoly acid acid anion adsorption, the presence of chloride ions does not affe

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 Ca, Mg, Cu form into a precipitate

The crystalization method of evaporation and extraction method in the preparation of APT will produce crystallization  liquor, leaving about 5% -10% of the WO 3  and part of the S, P, As, Mo, K, Na and other impurities. Since the APT crystallized  liquor contains a large number of impurity elements, it can not be directly returned to the process, in order to improve the metal recycle, it is necessary to set the auxiliary process to recycle the  of WO 3 . Due to the low energy consumption of membrane separation technology, it’s easy to achieve continuous operation and management, the process is easy to enlarge, the equipment is compact, it occupies a limited area and easy to use with other processes. In recent years, it widely attracted by the industry. Nano-Membrane filtration method is based on nano filtration equipment and put forward on the basis of great achievements. Nano membrane  filtration  was developed since the 1980 s, a new type of pressure driven membr

The crystalization method of evaporation and extraction method in the preparation of APT will produce crystallization liquor, leaving about 5% -10% of the WO 3  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 metal recycle, it is necessary to set up auxiliary processes to recycle WO 3  in the APT crystallization liquor. Selective precipitation method is developed from the tungsten and molybdenum separation technology. Scholars have found that the use of tungsten, molybdenum compounds of some of the structure and nature of the differences, learn from the successful experience of mineral processing flotation synthesis, synthesis of a precipitant, it can interact with molybdenum and other impurities to form a very small solubility of the compound, and the tungsten compounds remain in the solution to achieve selective separation of tungsten and impurities. In the treatment of

At present, in Chinese  ammonium paratungstate (APT) enterprises, the most commonly used crystallization method often requires a lot of ammonia, in the production of ammonium tungstate process there are two cases will escape ammonia. There are two cases will escape ammonia: One is the free ammonia in the ammonium tungstate solution, which quickly escapes in the early stages of the heating ammonium tungstate solution; the other is the reaction of ammonia, it is with the loss of the ammonia concentration in the solution and the precipitation of ammonium paratungstate, and constantly to escape. A mmonia l iquid is a high energy consumption products, the current market price is about 2400 RMB / ton. If the recycle rate of ammonia is 80%, the recycle value is considerable, and the recycle cost is low, it don’t need to increase in capacity, using the cooling cover to recycle,  only add a small amount of vacuum pump and water pump for electricity, thus removing the recycling c