- Turkish Journal of Engineering and Environmental Sciences
- Vol: 29 Issue: 6
- Recovery of Nano-Sized Cobalt Powder from Cemented Carbide Scrap
Recovery of Nano-Sized Cobalt Powder from Cemented Carbide Scrap
Authors : Sebahattin GÜRMEN
Pages : 343-350
Doi:10.3906/vet-1102-795
View : 4 | Download : 1
Publication Date : 9999-12-31
Article Type : Makaleler
Abstract :A process is developed to recover nano-sized cobalt from cemented carbide scrap (WC-Co) by nitric acid leaching and finally obtaining a nano-sized spherical pure cobalt powder by ultrasonic spray pyrolysis (USP). The optimization of the leaching and preparation of cobalt powders by USP are conducted within the framework of an environment-friendly and economical process, enabling reduced waste streams. According to the results obtained, it is possible to dissolve cobalt with high efficiencies (91.5%) via HNO3 leaching of cemented carbide scrap. The optimum leaching conditions were 90 m m, 25 °C, 2 h, 0.5 M HNO3, 900 rpm, and 1/10 solid/liquid ratio. The leach residue (WC-TiC) has a BET specific surface area of 1.08 m2/g and finds has a wide range of applications in key technologies, varying from mechanical to chemical industries. After leaching, nano-sized cobalt powder (300-700 nm) can be produced from Co(NO3)2 by ultrasonic spray pyrolysis with hydrogen reduction. The nano-sized powders can be used for the production of new nano-structured thermoelectric materials, nanomagnets, nanosensors and nano-structured tungsten carbide-cobalt powders.Keywords : Recovery, Hydrometallurgy, Ultrasonic spray pyrolysis, Nano-sized cobalt powder