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Abstract: Spent lithium-ion batteries contain lots of strategic resources such as cobalt and lithium together with other hazardous materials, which are considered as an attractive secondary resource and environmental contaminant. In this work, a novel process involving vacuum pyrolysis and hydrometallurgical technique was developed for the combined recovery of cobalt and lithium from spent lithium-ion batteries. The results of vacuum pyrolysis of cathode material showed that the cathode powder composing of LiCoO2 and CoO peeled completely from aluminum foils under the following experimental conditions: temperature of 600°C, vacuum evaporation time of 30min, and residual gas pressure of 1.0kPa. Over 99% of cobalt and lithium could be recovered from peeled cobalt lithium oxides with 2M sulfuric acid leaching solution at 80°C and solid/liquid ratio of 50gL−1 for 60min. This technology offers an efficient way to recycle valuable materials from spent lithium-ion batteries, and it is feasible to scale up and help to reduce the environmental pollution of spent lithium-ion batteries. [Copyright &y& Elsevier]

Abstract: Waste printed circuit boards (WPCBs) contain lots of valuable resources together with plenty of hazardous materials, which are considered both an attractive secondary resource and an environmental contaminant. In this research, a new process of “centrifugal separation+vacuum pyrolysis” for the combined recovery of solder and organic materials from WPCBs was investigated. The results of centrifugal separation indicated that the separation of solder from WPCBs was complete when WPCBs were heated at 240°C, and the rotating drum was rotated at 1400rpm for 6min intermittently. The results of vacuum pyrolysis showed that the type-A of WPCBs without solder pyrolysed to form an average of 69.5wt% residue, 27.8wt% oil, and 2.7wt% gas; and pyrolysis of the type-B of WPCBs without solder led to an average mass balance of 75.7wt% residue, 20.0wt% oil, and 4.3wt% gas. The pyrolysis residues contain various metals, glass fibers and other inorganic materials, which could be recycled for further processing. The pyrolysis oils can be used for fuel or chemical feedstock and the pyrolysis gases can be collected and combusted for the pyrolysis self-sustain. This clean and non-polluting technology offers a new way to recycle valuable materials from WPCBs and prevent the environmental pollution of WPCBs effectively. [Copyright &y& Elsevier]