Refining mechanisms of arsenic in the hydrogen reduction process of tungsten oxide

Research on the effect of liquid-liquid doping processes on the doped powders and microstructures of W–ZrO2(Y) alloys

“…The calcined powders were reduced by hydrogen reduction process at 900 °C for 2 h to obtain the reduced doped powders. H 2 atmosphere were conventionally applied as a reducing atmosphere to reduce the oxide tungsten as reported in [27][28][29][30][31][32][33][34].…”

“…In the past several years, liquid-liquid (L-L) methods involving molecular-level doping are used to prepare tungsten powder [27][28][29][30][31][32][33][34]. However, the doped tungsten powders in previous researches exhibit high degree of agglomeration, such as W-Y 2 O 3 powders [27,32], W-Re powders [28], W-Sc 2 O 3 powders [29] and W-As powders [34].…”

“…In the past several years, liquid-liquid (L-L) methods involving molecular-level doping are used to prepare tungsten powder [27][28][29][30][31][32][33][34]. However, the doped tungsten powders in previous researches exhibit high degree of agglomeration, such as W-Y 2 O 3 powders [27,32], W-Re powders [28], W-Sc 2 O 3 powders [29] and W-As powders [34]. A higher degree of agglomeration may lead to the tough calcination and reduction process [28], inadequate reduction, non-uniform distribution of doping phase [30], high energy consumption and strictly controlled sintering process (i.e.…”

Research on preparation process for the in situ nanosized Zr(Y)O2 particles dispersion-strengthened tungsten alloy through synthesizing doped hexagonal (NH4)0.33·WO3

“…To improve the quality of tungsten powders for preparing high-performance tungsten products, over the past several years, the liquid-liquid (L-L) doping techniques, particularly spray drying [14][15][16][17][18][19] and evaporation-precipitation/sol-gel process [20][21][22][23], were introduced to synthesize doped tungsten powders. On the one hand, it can avoid the introduction of detrimental contaminants during the mixing process of doping phase and tungsten powder.…”

“…On the other hand, it can lead to the doping phase evenly distributed in tungsten powders through the molecular-level mixing. However, the prepared doped tungsten powders also exhibit high degree of agglomeration, such as W-Y 2 O 3 powders [15,21], W-Re powders [16], W-Sc 2 O 3 powders [17] and W-As powders [23].…”