Tungsten Nitride Preparation

Tungsten nitride is a kind of material more popular in tungsten chemicals, some studies show that tungsten nitride is a new catalytic material, the surface properties and catalytic properties similar to platinum, tungsten nitride catalyst application can avoid the pollution caused by industrial catalyst sulfur vulcanization, therefore it has broad application prospects. Moreover, tungsten nitride is also a ceramic material with excellent mechanical and thermal stability. For these two applications, nanoscale tungsten nitride will have a significant advantage.

Here introduced by Liu Fubing and other scholars published tungsten nitride dry spray preparation method. In the main raw material is ammonium metatungstate, ammonium metatungstate dissolved in distilled water, centrifuged and then this aqueous spray dried in hot air 250  ℃, the rotational speed of 25000 rpm, the feed rate of 15ml / min under the conditions of spray drying a mixed solution of ammonium metatungstate and copper nitrate is subjected to centrifugal spray drying to obtain a precursor powder.

The powder was placed in a box furnace calcined at 600 ℃, 2 hours after desalination, dehydration to obtain W oxide powder; W oxide powder mixed with alcohol wet grinding, placed in a planetary ball mill, ball ratio 10: 1, powder and sprinkling fine quality ratio of 1: 1.5, speed 150rpm / min temperature grinding 8 hours, then the thickness of the material layer is 1 mm in the tube type electric furnace. The temperature control precision of the furnace is raised from 500 ℃ to 750 ℃, and the heat preservation is 2h. The resulting WO3 powder having a primary particle size of about 100 nm and a secondary particle size of 0.64 um was nitrided at ammonia gas at different temperatures to completely convert the powder to WN at 650 °C and its grain size is 35 nm, and the secondary average particle size after agglomeration at room temperature is 6.4 um.

The results show that the tungsten nitride spray drying process is more stable than other tungsten nitride manufacturing processes, and is the most ideal tungsten nitride preparation method.

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