Electrochemical Leaching of Cobalt from Cobaltite:\nBox-Behnken Design and Optimization with Response Surface Methodology

Cobalt, a critical\nmetal, is anticipated to increase in market\ndemand in the next couple of decades, particularly as a battery material\nused in electric vehicle application. To boost the domestic production\nof cobalt in the United States, an electrochemical process has been\ndeveloped to recover cobalt from a cobaltite-rich concentrate and\nproduce cobalt- and arsenic-rich leachate. The leaching efficiency\nof cobalt was optimized with a response surface methodology by modifying\nthe electrochemical parameters. A series of experiments based on the\nBox-Behnken design of experiments were carried out using ferric iron\nas an electrochemically generated oxidant to leach metals from the\nconcentrate. Operating parameters, such as electrochemical cell current,\niron/arsenic molar ratio, and anolyte acidity, were optimized for\nmaximum cobalt recovery. A predicted 73% cobalt extraction efficiency\ncan be achieved with the electrochemically assisted leaching method\nwithin 24 h. Compared to other leaching methods, such as bioleaching,\nelectrochemically assisted leaching shows a promising alternative\nfor extracting metals from mining concentrates, showing higher efficiency\nin less time and under mild conditions.