A novel method for preparing ultrafine molybdenum powder. (April 2021)

• Record Type: Journal Article
• Authors: Zhang, He; Li, Zhi-Bo; Zhang, Guo-Hua; Chou, Kuo-Chih
• Is Part Of: International journal of refractory metals & hard materials. Volume 96(2021)
• Publication Date: 2021-04
• Subjects: Molybdenum powder -- Grain size -- Dispersity -- Carbothermic reduction -- Hydrogen reduction; Heat resistant alloys -- Periodicals; Refractory materials -- Periodicals; Metallography -- Periodicals; Alliages réfractaires -- Périodiques; Matériaux réfractaires -- Périodiques; Métallographie -- Périodiques; Heat resistant alloys; Metallography; Refractory materials; Periodicals; Electronic journals; 669.73
• DOI: 10.1016/j.ijrmhm.2021.105491
• Languages: English
• ISSNs: 0263-4368

Abstract

Abstract: In this paper, using MoO3 as molybdenum source, ultrafine molybdenum powder is synthesized by a novel method composed of carbothermal reduction and the following hydrogen reduction stages. First, ultrafine MoO2 powders are successfully prepared via reduction of commercial MoO3 by carbon black with the molar ratio of C/MoO3 ranging from 0.5 to 0.7 in the temperature range of 550 °C to 650 °C. after that, the ultrafine Mo powder with a good dispersity is synthesized through hydrogen reduction of the as prepared ultrafine MoO2 . The grain size and residual carbon content of the finally obtained ultrafine molybdenum with molar ratio of C/MoO3 of 0.5 at 800 °C are about 200 nm and 0.04 wt%, respectively. Moreover, the residual carbon content of the product could be decreased to about 0.006 wt% at 1000 °C. the invention is characterized on short process flow, simple operation and low cost to prepare ultrafine molybdenum powder. Thus, it has great potential in large-scale industrial production Graphical abstract: Unlabelled Image Highlights: Ultrafine Mo powder with a high purity was prepared by a two-step process. Ultrafine MoO2 powder was prepared at a C/MoO3 ratio of 0.5–0.7. Ultrafine Mo powder was obtained by reducing ultrafine MoO2 with hydrogen.