Abstract

SIERRA-PEREZ, Sebastián; ROJAS-REYES, Néstor Ricardo; MARTINEZ-ZAMBRANO, José  and  ROJAS-SARMIENTO, Hugo Alfonso. Thermodynamic and kinetic study of the recovery of tungsten and cobalt from tool waste. Rev.fac.ing.univ. Antioquia [online]. 2018, n.89, pp.44-51. ISSN 0120-6230.  https://doi.org/10.17533/udea.redin.n89a06.

In the present research work, the recovery of tungsten and cobalt from waste coming from tungsten carbide-cobalt (WC-Co) tools, which are widely used in the metalworking industry, was analyzed. The WC-Co waste was characterized by X-ray diffraction and scanning electron microscopy with microanalysis (SEM/EDS). The process started with the oxidation of the waste to obtain a mixture of oxides (WO3 and CoWO4). The ΔH and ΔG were calculated both for the oxidation and reduction processes. Thermodynamic and non-isothermal kinetic analyses were carried out to obtain a stability diagram where theoretical and experimental data are defined by transformation lines as a function of temperature; in addition, the apparent activation energy was determined. By a hydrogen reduction process, high-purity tungsten and cobalt in metallic form were obtained.

Keywords : Tungsten; Cobalt; OPT/RPT; thermodynamics; non-isothermic kinetics.

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