In order to obtain pure APT or W0 3 from the crude sodium tungstate solution obtained by alkali decomposition of tungsten mineral raw materials, in principle, the following tasks must be completed: purifying and removing impurities P, As, si; transforming tungsten into a Na 2 W0 4 solution form into (NH 4 ) 2 WO 4 solution, (NH 4 ) 2 WO 4 solution evaporative crystallization to obtain APT, in addition to undergoing the molybdenum removal process, in order to accomplish the above tasks, the common process is integrated as shown in the following figure, that is, the commonly used processes are:
(1) Na 2 W0 4 solution is ion-exchanged to remove P, As, Si and transformed into pure (NH 4 ) 2 W0 4 solution, and crystallized to obtain APT o
(2) The Na 2 W0 4 solution is chemically precipitated to remove P, As, Si and then converted to (NH 4 ) 2 W0 4 solution. The transformation is mainly by extraction method and ion exchange method.
(3) The Na 2 W0 4 solution was removed by chemical precipitation method after P, As, and Si, and then APT was obtained by the classical method.
Seamless Aluminium Tubing,Seamless Rectangualr Pipe,Seamless Pipe Connection
Guangdong Tonglian Pipeline Technology Co., Ltd , https://www.tonglianpipeline.com