WC powder was obtained from recycling cemented carbide scraps. This metal power contained tungsten carbide (WC) at 89.17% titanium (Ti) at 4.90% tantalum (Ta) at 3.56% niobium (Nb) at 1.31% and molybdenum (Mo) at 0.93%. Its particle size and distribution was in the range of 0.03-85.31 µm. After quality improvement of the metal powder by ball milling screening and separating the compounds the result showed that the particle size of the metal powder was decreased to 0.01-0.10 µm (10-100 nm). The average size of the powdered particle was 28 nm. The tungsten powder was in more perfect condition by 95.85%

The recycling of materials is the recovered process and the important approach for sustainable development. This research is to study recycling tungsten carbides from cemented carbide scraps by extracting the dissolved of binder phase and to study the un-dissolved substrate which stayed condition and size in WC particles. The experiment of this research starts in laboratory with electrolysis is found that the appropriate operating potential is 0.20-1.40 volts at 30-80 oc treated in 1N-7N HCl concentrations aqueous solution as well as the movement of solution and specimens had an effect on capacity of dissolution. Additionally these factors are affected to purity and passivation of WC particles. According to the above experiment it leads to design and create the semi-automatic cemented dissolution machine with electrolysis. This machine can contain the scraps up to 2.5 kilograms in rev 0-25 rpm (revolutions per minute) at electric current 0-50 ampere in electric voltage 0-15 volts. Its flowing process can be 15 lpm (litre per minute) and minute) and temperature is up to 90 oc. Furthermore there are the relative WC power invention processes included residues washing leaching ball milling drying screening and quality examination. The result of developed machine is capacity of tungsten carbide production is in the range 16-50 gram/hour the obtained powder is 97.49% of tungsten carbide (WC powder) which contained a few amount of cobalt. However the dissolution of cemented carbides with this machine can be selected the optimized factors to produce tungsten carbide (WC) to purify more than 99% ball milled them in the most suitable size and particle sized distribution between 0.30-20.00 μm. Afterwards combining cobalt 15% (WC-15%Co) and producing to cemented carbides insert tools rectangle as SNMG standard 120408 it appears that insert tools has a hardness not less than 1430 HV density not less than 14.10 g/cm³. In the other hands the production of tungsten carbides with advanced technology of dissolution machine and manufacturing machine to produce purely tungsten carbides powder has been required an investment charge of new research and development more than 9481888 baht.

This research is to study the recycle process of hard materials high hardness type and cemented carbide produced by press forming and sintering process included cemented carbide mixed with tungsten carbide cobalt silicon titanium and others. The research aims to recovery tungsten to use it again. It starts in cleaning and ball milling materials for resizing from length 12-25 mm. width 10-15 mm and thickness 2.5-8.0 mm. then disintegrated with the electric-chemical process filtering metal powder cleaning and drying. The result of dissolved materials with electricchemical process in 85% condensed HCl 6-24 volts and 3-10 amperes. The solution heats up 180 degree Celsius is found that material will be 550 11m of W03 the same as usage of Phosphoric Solution. The result of the study in dissolved materials by using the conductor of electricity is found that usage of cobalt is the best to disintegrate tungsten carbide better than tungsten carbide and stainless steel 10-15%. The result of this research is found that the best practice of tungsten carbide recovery is dissolved materials with electric-chemical process in not over 7N condensed HCl 6.00 volts and 3.00 amperes. The metal powder will be almost 100% pure tungsten carbide and particle sized distribution is 34-360 11m. After ball milling for 24 hours particle sized distribution is less than 60 11m compared with the imported metal powder. It is concluded that the recycle of cemented carbide into tungsten carbide powder qualified for sintering work and produced to the durable hard materials. It ensures that this research is useful for the related industry and the approach for production of tungsten carbide which was instead of the imported metal powder.