钨─钴混合氧化物直接气相还原/碳化相变过程

来源期刊：中南大学学报(自然科学版)1996年第3期

论文作者：吴恩熙 钱崇梁 张卫兵

文章页码：303 - 307

关键词：钨氧化物; 钴氧化物; 氢还原; 碳化; X射线衍射; 相变

Key words：tungsten oxide; cobalt oxide; H₂-reduction; carburization; X-ray diffraction; phase transition

摘    要：用XRD和SEM对钨－钴混合氧化物(W₂₀O₅₈+CO₃O₄)的氢还原及在不同组成的H₂/CH₄混合气体中的碳化过程进行了研究.结果表明,在850℃以上氢还原产物是α－W+CO₃W+CO₇W₆三相混合物.纯蓝钨(W₂₀O₅₈)或钨－钴混合氧化物都能在较低的温度下(900～1000℃)被甲烷气相碳化成WC,碳化速度和游离碳的析出均与碳化温度及H₄/CH₄混合气相的组成有关.作者给出了最佳的碳化工艺条件

Abstract: The processes of H₂-reduction and carburization by hydrogen/methane mixtures with rarious gas phase composition for the tungsten-cobalt oxide mixture (W₂₀O₅₈+Co₃O₄)wereinvestigated by means of XRD and SEM analyses. The results show that the oxide mixture was reduced to a-W, Co3W and Co7W6 at the temperatures higher than 850 ℃ in H₂. The pure blue tungsten oxide (W₂₀O₅₈) or W-Co oxide mixture can be carburized with H₂/CH₄ gas mixture at lower temperature (900～1000℃). Both the carburizing rate and the deposition of free carbon are closely related to the caburizing temperature and the H₂/CH₄ mixture constitution. The present paper gives an optimal combination of processing parameters for the carburization.