Liquid-state alkane back flow method for preparing nanometer tungsten carbide

Abstract

The invention relates to a method for preparing nanometer tungsten carbide powder from liquid-state alkane through back flow carbon covering. Sodium tungstate is used as a tungsten source, and a liquid-state alkane mixture (C11 to C16) is used as a carbon source. The invention has the sequential process steps of material preparation, back flow, drying, material charging, high-temperature heat treatment and sampling. The back flow time and the back flow temperature of raw materials are controlled, precursor powder with different carbon contents can be prepared, and high-purity nanometer tungsten carbide powder can be prepared through the heat treatment process. The tungsten carbide powder prepared by the method has the average granularity between 30 and 60 nm and the average grain fineness number between 20 and 30 nm. The method of the invention has simple process and lower cost. Compared with an ordinary heat reducing method, the invention saves energy sources, and can easily realize the scale preparation.

Description

technical field [0001] The invention belongs to the field of hard alloy and catalyst material preparation, and in particular relates to a preparation method for preparing tungsten carbide nano powder with a novel organic-inorganic composite precursor. Background technique [0002] In recent years, transition group metal carbides have aroused great interest of researchers due to their important scientific value and potential huge application prospects, and people are competing to use different ideas to synthesize such carbides. [0003] WC is one of the most important materials in transition metal carbides. It has excellent properties such as high melting point, hardness, thermal stability and mechanical stability. It is widely used in the production of cemented carbide materials, in cermets, machining, metallurgy There are important applications in mining, aerospace and other fields. In addition, since the surface electronic structure of WC is similar to that of Pt, it has ...

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Problems solved by technology

However, these two methods still have defects in varying degrees: the sol-gel method, the raw material is easily hydrolyzed, the shrinkage is large during drying, the cost is high, the yield is low, and the process is cumbersome; the gaseous alkane cracking carbon encapsulation method requires high equipment requirements and consumes The energy is large, it is difficult to achieve carbon encapsulation in a monodisperse state, the prepared WC grains are too large, and the product purity is low, which also limits the application of these two methods to a certain extent.

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