Crystallisation and Processing of Ammonium Paratungstate (APT)

摘要

This paper starts with the chemistry of tungsten in aqueous solutions. Various aspects of the crystallisation of the hydrates of ammonium paratungstate (APT) will be discussed in addition. This is then followed by the chemistry of the first pyrometallurgical treatment in non-sag (NS) tungsten manufacturing, the processing of APT into tungsten blue oxide. The section is mainly devoted to the chemistry of the thermal decomposition of APT in various atmospheres. Finally, parameters controlling tungsten blue oxide quality will be discussed.