Recycling E-waste into high-value ceramics: synthesis of porous magnesium aluminate spinel from recovered aluminum of spent lithium-ion batteries and bischofite

Abstract

To mitigate the environmental impact associated with the ultimate disposal of lithium-ion batteries, it is essential to keep materials in use for as long as possible. This can be achieved by recycling components contained in spent batteries and reusing them in the production of new value-added materials. This study aims to reuse the aluminum foil recovered from the cathode of spent lithium-ion batteries to synthesize magnesium aluminate spinel, a technological ceramic product, through reaction with bischofite. A pyrometallurgy route was employed, involving calcining a mixture of the recovered aluminum foil and bischofite in an air atmosphere. Non-isothermal calcination was conducted to identify the temperature at which the spinel phase begins to form. Additionally, isothermal calcination experiments were performed to evaluate the optimal conditions for achieving complete spinel formation. The onset temperature of the magnesium aluminate spinel synthesis was determined to be 550°C. During the synthesis process, the spinel undergoes morphological changes, becoming a porous material. Complete formation of the porous spinel is accomplished at 900°C for 120 min. This approach mitigates the environmental impact associated with the disposal of discarded batteries and reduces the cost of the synthesis process by employing low-cost raw materials.