Ammonium Metatungstate and Ammonium Tungstate Difference
Difference of ammonium metatungstate (AMT) and ammonium tungstate firstly lies in that AMT is downstream product of ammonium tungstate; in the tungsten metallurgical industry of tungsten concentrate to tungsten powder, the preparation process of ammonium tungstate and AMT is that ammonium tungstate solution crystallized and lost some ammonia and water to generate ammonium paratungstate (APT); APT thermal decomposition to get AMT.
Ammonium metatungstate has several forms of crystal depending on the different crystallization conditions: (NH4)6H2W12O40.nH2O or (NH4)6H2W12O40.XH2O or (NH4)6H2W12O40；
Ammonium tungstate formula is (NH4)10W12O41~xH2O, and it will lose one molecule crystal water at 100℃.
Ammonium tungstate can be used for the preparation of phosphorus ammonium tungstate, and achieve all applications of ammonium metatungstate because AMT is coming from ammonium tungstate, like producing tungsten trioxide or blue tungsten oxide to produce tungsten metal powder; the downstream products of metal tungsten powder are tungsten material series, such as electric vacuum materials of tungsten bar, wire; series of alloys, such as tungsten carbide, alloy blade, drill and mold; as an additive in petrochemical industry.