Study on the Decomposition of the Tungsten Residue Using Concentrated Hydrochloric Acid by Reflux Method

Abstract

A method of decomposition for tungsten residue using concentrated hydrochloric acid by reflux is presented. The hydrochloric acid concentration, hydrochloric acid consumption and reflux time were investigated. The decomposition of tungsten residue using concentrated hydrochloric acid by reflux was compared to non-reflux. The results show that the reflux method is significantly better than the non-reflux method. The optimum decomposition conditions for tungsten residue are that the hydrochloric acid consumption is at 38.55 mmol/g and the mixture of concentrated hydrochloric acid and tungsten residue are heated to reflux under stirring for 4 h. The decomposition ratio is Fe 98.88%, Mn 98.63%, RE 99.13%, Sc 98.78%, Th 97.84%, Ti 97.11%, U 96.92%, Zr 95.76%, Nb 6.65%, Ta 3.54%, and W 0.89%.