Kohsei Co.,Ltd. Kitakyushu Plant


Reclaimed Cemented Tungsten Carbide

Ionization Process

As the Zn-distillation process has limitation of productivity and products’ species, we have developed an ionization process for reclaimed cemented tungsten carbide scraps. In the ionization process, the binder metal is ionized into liquid solution and WC particles are left alone. The WC powders which are recovered by this process have the same or close-to quality as virgin powders.

Reclaimed Products

SEM image of Reclaimed WC Powder
SEM image of Reclaimed WC Powder

Ionization-Reclaimed WC Powders(Typical)

Element Sample① Sample② Sample③
C 6.14 6.11 6.10
O 0.330 0.381 0.287
Co 0.0430 0.109 0.0764
Ni 0.0077 0.0229 0.0124
Cr 0.0666 0.0722 0.0482
Fe 0.0056 0.0204 0.0216
Cu 0.0002 0.0008 0.0009
Al 0.0002 0.0010 0.0033
Ti 0.0156 0.0520 0.0903
Cd <0.0001 <0.0001 <0.0001
Mn 0.0001 0.0006 0.0008
Mg 0.0006 0.0008 0.0011
Mo 0.0009 0.0073 0.0262
Ca 0.0059 0.0049 0.0036
Na 0.0010 0.0010 0.0010
K 0.0010 0.0010 0.0010
Particle Size*1
5.0 3.0 2.3
*1 F.S.S.S.

Zinc-Reclaimed WC Powders(Typical)

Element Sample① Sample② Sample③
C 5.39 5.62 5.70
Co 14.1 8.44 4.94
Ni 0.290 0.755 0.0105
Cr 0.0901 0.412 0.0300
Fe 0.0500 0.0503 0.0302
W 80.1 84.5 89.3
Zn 0.0012 0.0011 0.0019
Particle Size*1
2.1 2.3 2.6
*1 F.S.S.S.
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Kohsei Kitakyushu plant started recycling cemented carbide scraps such as WC rolls, drills by Zn-distillation process since the plant was built in Feb 2000. It is known that the cemented carbide is composed by super-hard particles (WC, TiC, VC, etc) and binder metals (Co, Ni, Fe, etc). In the Zn-distillation process, melt Zn dissolves the binder metals so that the hard particles could fall apart easily. After Zn is evaporated at elevated temperatures, binder metals precipitates on the surface of hard particles. The distillated alloy is milled into fine powders finally.
One of the advantages of Zn-distillation process is that the reclaimed cemented carbide powders have the same chemical composition as raw materials. Besides, it is an economical and environment-friendly process which does not generate any wastes and pollution.


High Quality Reclaimed Products

With the shortage of the supply and increase of prices of raw materials, demands for reclaimed products have been rising. More and more reclaimed WC products are used for cemented tungsten carbide products. Our plant always takes the quality assurance as our first priority and follows the regulations of environment protection, personal health and laws. We have established our new analysis center and installed many advanced instruments such as ICP, AES, SEM, EDS, Fluorescent X-ray, PSD analyzer. The more accurate and repeatable analysis and evaluations make our products more reliable and stable.


*We can customize specifications to meet customers' needs. Please feel free to contact us.
*The tolling service of cemented tungsten carbide scrap is also available at our plant.
*We purchase cemented tungsten carbide scraps at any time.

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