Carburization of ammonium paratungstate by methane: The influence of reaction parameters

被引：12

作者：

de Medeiros, F. F. P. ^{[1
]}

da Silva, A. G. P. ^{[2
]}

de Souza, C. P. ^{[3
]}

Gomes, U. U. ^{[1
]}

机构：

[1] Univ Fed Rio Grande do Norte, DFTE, Dept Fis Teor & Expt, BR-59072970 Natal, RN, Brazil

[2] Univ Estadual Norte Fluminense, Lab Mat Avancados, Campos Dos Goytacazes, Brazil

[3] Univ Fed Rio Grande do Norte, Dept Engn Quim, BR-59072970 Natal, RN, Brazil

来源：

INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS | 2009年 / 27卷 / 01期

关键词：

Tungsten carbide; Carburization; Gas-solid reaction; Ammonium paratungstate; TUNGSTEN CARBIDE; MIXTURES;

D O I：

10.1016/j.ijrmhm.2008.03.001

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

Tungsten carbide powder is conventionally produced by carburization of tungsten powder by carbon black in a solid-solid reaction. This paper reports the carburization of ammonium paratungstate by methane to yield tungsten carbide at low temperature in short times. The carbide powder is fine grained and has specific surface area around 35 m(2)/g. This makes the powder interesting for catalysis and fine grained hard metals. The influence of reaction parameters such as temperature, gas flow, composition of the reaction gas and powder charge are investigated by means of gas chromatography and XRD with Rietveld refining. The overall reaction time is the sum of reduction and carburization times of the sequential reactions. Some parameters, like gas composition affects only the carburization rate, other parameters, such as gas flow affects both reactions. (C) 2008 Elsevier Ltd. All rights reserved.

引用

页码：43 / 47

页数：5

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