Optimum Conditions of Dismantlement for Recovery of Valuables from Spent Lithium Primary Batteries

Abstract

Dismantlement of lithium primary batteries without explosion is required to recycle the lithium primary batteries which could be exploded by heating too much or crushing. In the present study, the optimum discharging condition was investigated to dismantle the batteries without explosion. When the batteries were discharged with 0.5 kmol·m 3 sulfuric acid, the reactivity of the batteries decreased after 4 days at 35 ℃ and after 1 day at 50 ℃, respectively. This result shows that higher temperature removed the high reactivity of the batteries. Because loss of metals recycled increases when the batteries are discharged only with the sulfuric acid, discharging process using acid solution and water was newly proposed. When the batteries were discharged with water during 24 hours after discharging with 0.5 kmol·m 3 sulfuric acid during 6 hours, the batteries discharged were dismantled without explosion. Because decrease in loss of metals was accomplished by new process, the recycling process of the batteries could become economic by the 2-step discharging process.