Preparation of nano-crystalline tungsten powders from gaseous WO2(OH)2

Abstract The industrial production of tungsten powder is carried out by the reduction oxide via hydrogen. In this process, size W particles limited to particle sizes larger than 100 nm. To get below limit, alternative processes are needed. current work, possibility preparing nm a vapour phase volatile WO 2 (OH) hydrogen was investigated. process consists two stages. first stag,e formed reacting 3 with water at temperatures 1000–1100 °C. second stage, reduced about 1000 °C form metallic tungsten. influence parameters such as furnace temperature, humidity and gas flow on evaporation formation characterization resulting powders performed X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) transmission (TEM). By optimization reaction conditions, content 70 at% besides oxides produced metal down 5 Further should lead high product yield. Due small size, applications in catalysis might be possible, although an realization seems unrealistic moment.