Harmless treatment of waste carbon slag with secondary iron-aluminum slag
Enterprises usually use hydrometallurgical process to recover valuable metals in retired lithium-ion batteries,and waste carbon slag and secondary iron-aluminum slag are produced in the recycling process.Secondary iron-aluminum slag is heavy metal solid waste due to the high content of nickel,copper and other heavy metals,and needs to be treated of harmlessly.Based on the concept of"treating waste with waste",it is proposed to co-dispose secondary iron-aluminum slag and waste carbon slag,and recover valuable metals through desulfurization,reduction roasting and melt separation.The results show that with the increase of roasting temperature and the extension of desulfurization time,the residual sulfur content in the secondary iron-aluminum slag gradually decreases,and the desulfurization rate gradually increases.When the roasting temperature was 1 300 ℃ and the reaction time was 2.5 h,the remaining sulfur content in the slag was 0.068％and the desulfurization rate was 99.31％.The recoveries of nickel,cobalt,copper and iron were 69.43％,74.52％,79.05％and 79.29％,respectively.The leaching toxicity of the slag was detected,and the contents of copper and nickel in the leaching solution were 0.013 and 0.984 mg/L,respectively,which were far lower than the GB 5085.3-2007 standard,and the harmless treatment of the slag was realized.
secondary iron-aluminum slagreducing roastingmelting separationvaluable metal recoveryharmless
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