
High-calcium ammonium paratungstate means the ammonium paratungstate powder that has excessive Ca content. The phenomenon of excessive Ca content in APT products is likely to occur during the production of APT by ion exchange process. The high-calcium APT must be reprocessed as it will not only affect the quality of tungsten carbides, but also cause a waste of tungsten resources to some extent. The conventional process to treat ammonium paratungstate with severely Ca content has the disadvantages of long process…