OF VERY FINE TUNGSTEN CARBIDE POWDER
R. A. Apakashev
and S. Ya. Davydov
Translated from Novye Ogneupory, No. 8, pp. 54 – 56, August 2015.
Original article submitted December 10, 2014.
An energy-saving method is proposed for synthesizing very fine tungsten carbide powder within which the
starting tungsten-containing raw material used is ammonium paratungstate, pressed with carbon-containing
material. The tungsten carbide preparation method proposed provides marked energy saving as a result of re
ducing temperature and starting reagent heating duration. Predominance of tungsten carbide particles in syn
thesized material is demonstrated, corresponding to two main size ranges: 100 – 200 nm and 2.0 – 8.0 mm.
Clear facets are typical for particles of the micron range, missing from nanosize particles.
Keywords: refractory ceramic, tungsten carbide, very fine powder, synthesis, energy saving.
Materials are often used not containing oxygen within
their composition as a refractory ceramic component. In
view of this the industrial importance of such typical high-
temperature resistant carbides as WC, SiC, TaC, and TiC 
have acquired industrial importance. Refractories prepared
from these materials exhibit high strength and corrosion re-
sistance, and also resistance to prolonged high-temperature
A widespread method of ceramic preparation is powder
sintering. The fineness of the starting refractory material is
important. A small particle size for sintered powder facili
tates a marked increase in operating parameters of refractory
ceramic. However, preparation of nano- and microdispersed
powders of different materials is an energy-consuming pro
cess, which causes their high cost.
The present work is carried out with the aim of develop
ing an energy saving method for preparing very fine tungsten
carbide powder. Energy saving is achieved as a result of re
ducing synthesis temperature and duration. Additionally
there is a reduction in material consumption due to use of
available tungsten-containing raw material.
Known methods for preparing refractory metal carbides
as a rule are based on reduction of metal-containing oxide
raw material with simultaneous carbidization. Carbide prepa
ration proceeds from the corresponding oxides, which are
carbidized by carbon-containing material at temperatures
consisting of 50 – 75% of the carbide melting temperature.
Tungsten carbide may be prepared in normal furnaces at
1573 – 1673 K from a mixture of tungsten metal and car-
bon-containing material powders. As a rule, carbidization is
carried out in a reducing (often hydrogen) atmosphere
[2 – 4].
There is a marked increase in both energy consumption
for preparing final product and also the cost of the method
for preparing nanosize tungsten carbide powder, including a
powder mixture of tungsten and graphite in a sealed reac
tor. Tungsten powder is used with a particle size of
100 – 200 nm, heating is accomplished over a long time (up
to 70 h) of a constantly rotating sealed reactor.
We have managed to minimize the disadvantages noted
for widespread methods of preparing very fine tungsten car
bide powder using ammonium paratungstate as a starting raw
material, pressed with a carbon-containing reducing agent.
Use of ammonium paratungstate provides marked energy
saving, due to a reduction in the overall process duration, and
also the possibility of synthesis at a temperature not exceed
ing 1273 K. Use of ammonium paratungstate instead of tung
sten metal nanopowder additionally reduces the cost of the
tungsten carbide obtained.
Ammonium paratungstate is an intermediate product of a
widespread production process for preparing tungsten metal
from the corresponding concentrate. On heating ammonium
paratungstate there is initially decomposition and WO
mation. Then tungsten (III) oxide is reduced to metal. Com
Refractories and Industrial Ceramics Vol. 56, No. 4, November, 2015
1083-4877/15/05604-0425 © 2015 Springer Science+Business Media New York
FGBOU VPO Ural State Mining University, Ekaterinburg, Rus