The Existence Form and Distribution of Mn in Production of Tungsten Products

摘要

The effect of doping different content of Mn into ammonium paratungstate (APT) on the production of tungsten products was studied systematically. The calcination of APT, reduction of WO_3 and carbonization of W were studied in sequence. The phase composition, powder morphology, existence form and distribution of Mn were analyzed by X-ray diffraction, scanning electron microscope and transmission electron microscope, respectively. The results showed that Mn converted from MnCl_2 to Mn~(2+)WO_4 during reduction process. And then Mn~(2+)WO_4 converted to Mn_5C_2 in the process of carbonization. Besides, Mn finally existed as the form of (Mn, W) C solid solution and Mn_5C_2. The distribution of Mn was always in the low contrast areas.