Tungsten Oxide

Ion Exchange method is the process of preparing ammonium metatungstate . It is made from ammonium wolframate solution or ammonium paratungstate.  This method is also one of the main methods for preparing ammonium metatungstate (AMT) at present. The main mechanism of ion exchange method is that use NH 4+  in H+ solution of strong acid or weak acid type H+ cation resin to process ion exchange. Under the condition of pH 3.5, H+ enters solution , cook for 5 hours at 98 °C. Converting ammonium tungstate into stable ammonium metatungstate solution. Then after evaporation and concentration, ammonium tungstate was converted to stable ammonium metatungstate solution. Again after evaporation and concentration, AMT crystals were prepared by freeze crystallization or spray drying. The resin saturated by NH 4+  is recycled after treatment with hydrochloric acid solution.  Because of the simple process and conv...

Ion Exchange method is the process of preparing ammonium metatungstate.It is made from ammonium wolframate solution or ammonium paratungstate.  This method is also one of the main methods for preparing ammonium metatungstate  (AMT) at present. The main mechanism of ion exchange method is that use NH 4+  in H+ solution of strong acid or weak acid type H+ cation resin to process ion exchange. Under the condition of pH 3.5, H+ enters solution , cook for 5 hours at 98 °C. Converting ammonium tungstate into stable ammonium metatungstate solution. Then after evaporation and concentration, ammonium tungstate was converted to stable ammonium metatungstate solution. Again after evaporation and concentration, AMT crystals were prepared by freeze crystallization or spray drying. The resin saturated by NH 4+  is recycled after treatment with hydrochloric acid solution.  Because of the simple process and conve...

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 prese...