In:
Tungsten, Springer Science and Business Media LLC, Vol. 4, No. 1 ( 2022-03), p. 60-66
Abstract:
The industrial production of tungsten powder is carried out by the reduction of tungsten oxide powder via hydrogen. In this process, the size of the W particles is limited to particle sizes larger than 100 nm. To get below this limit, alternative processes are needed. In the current work, the possibility of preparing W powder below 100 nm via a vapour phase reduction of volatile WO 2 (OH) 2 by hydrogen was investigated. The process consists of two stages. In the first stag,e WO 2 (OH) 2 is formed by reacting WO 3 with water vapour at temperatures of 1000–1100 °C. In the second stage, WO 2 (OH) 2 is reduced by hydrogen at about 1000 °C to form metallic tungsten. The influence of process parameters such as furnace temperature, humidity and gas flow on the WO 2 (OH) 2 evaporation and formation of tungsten powder was investigated. The characterization of the resulting powders was performed by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). By optimization of the reaction conditions, powder with a metallic tungsten content of about 70 at% besides tungsten oxides was produced with metal particle sizes down to 5 nm. Further optimization should lead to a high tungsten content and a high product yield. Due to the small particle size, applications in catalysis might be possible, although an industrial realization of the process seems unrealistic at moment.
Type of Medium:
Online Resource
ISSN:
2661-8028
,
2661-8036
DOI:
10.1007/s42864-021-00118-1
Language:
English
Publisher:
Springer Science and Business Media LLC
Publication Date:
2022
detail.hit.zdb_id:
2970242-2
Permalink
