Cobalt Recovery by the Chlorination-Volatilization Method
- PDF / 528,213 Bytes
- 6 Pages / 593.972 x 792 pts Page_size
- 8 Downloads / 195 Views
alt is an important strategic metal and is widely used in the production of batteries, high-temperature alloys, cemented carbides, catalysts, and magnetic alloys.[1] The cobalt reserves and production of China account for 1.1 mass pct and about half of the world’s reserves and production, respectively. With the increase of cobalt consumption, there are large amounts of cobalt-bearing wastes produced every year in China, whose cobalt contents are much larger than China’s mean grade of cobalt ores (0.02 mass pct).[2] Therefore, it is pretty significant for the use of cobalt-bearing wastes. Different processes have been developed for the recovery of cobalt depending on the sources of cobalt-bearing wastes,[3] including the beneficiating method, pyrometallurgy process, hydrometallurgy process, microorganism leaching method, and their combined processes.[2] Usually, the pyrometallurgy process is adopted for the pretreatment of cobalt-bearing wastes, followed by a subsequent hydrometallurgical step. The pyrometallurgical pretreatments include sulfation roasting,[4,5] the reduction smelting process,[6,7] and chloride roasting.[8–11]
PEI-WEI HAN, LI XIAO, YONG-LIANG WANG, YONGGANG LU, and SHU-FENG YE are with the State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China. Contact email: [email protected] Manuscript submitted June 27, 2018. METALLURGICAL AND MATERIALS TRANSACTIONS B
During sulfation roasting, cobalt is converted into soluble sulfate. Erust and Akcil[4] used the sulfation roasting method for the preliminary enrichment of nonferrous metals in pyrite ashes at a temperature between 423 K and 573 K with a certain dosage of concentrated H2SO4. After roasting, about 70 pct of cobalt was recovered by subsequent acid leaching. Arslan and Arslan[5] extracted copper, cobalt, and zinc from the copper smelter and converter slags by roasting with sulfuric acid. Also, the cobalt recovery rate reached 87 pct after roasting for 2 hours at 423 K with a 3:1 acid/slag ratio. For the reduction smelting process, valuable metal oxides in molten slag are reduced by reducing agents and cobalt-bearing alloy is formed. Zhai et al.[6] studied the cobalt recovery from converter slag. About 94.02 pct of cobalt can be recovered under optimum conditions. It was important to select suitable slag modifiers. The addition of slag modifiers could affect the basicity and fluidity of slag, as well as the activity coefficients of iron oxide, silica, and cobalt oxide, and improve the base metal recovery rate and influence the selectivity of the recovery.[7] Cobalt is converted into soluble chloride during chloride roasting. Zhang et al.[8] studied the recovery of copper and cobalt by roasting with ammonium chloride. They investigated the effects of the ore particle size, ammonium chloride concentration, roasting time, and temperature (473 K to 623 K). About 90 pct of cobalt was recovered under the optimal conditions. A two-stage chlorinating roasting of low-grade nickel-copper matte w
Data Loading...
