Using Roasting - Lithium Cobalt Oxide Flotation Study Recovered From Waste Lithium Batteries

Waste lithium-ion battery is composed of positive pole, negative pole, electrolyte,diaphragm and metal shell，LIBs have many superior behaviors and widely used in mobilephones, notebook computers, aerospace and other high-end field. Meanwhile, environmentpollution caused by waste LIBs became more and more serious with the huge consumptionand unprecedented update speed. Now, recycling valueable metals from waste LIBs is gettingmore and more attention and achieve the comprehensive utilization of resources.LiCoO2is the main composition of anode materials in Waste lithium-ion battery, whichhave excellent discharge capacity, charge and discharge reversibility and very high recoveryutilization value.Using roasting-flotation process recover LiCoO2from Waste lithium-ionbattery, the main process includes crushing process, screening process, roasting process andflotation process.In crushing process, using wet impact crusher grind waste lithium-ion battery, the maininfluence factors include crushing amount, crushing time and water consumption. Orthogonalanalysis influencing factors by Design-experts software, curshing time from20s to60s,crushing amount from one to three and water consumption from400L/h to600L/h.Orthogonal experiment results show that when crushing amount is two, crushing time is40s and water consumption Q=600L/h, crushing process reach optimum technology condition,the credibility of the optimized combination is more than96%, which display technology hasexcellence fragmentation effect.In screeing process, using standard sieve set (2/1/0.5/0.25/0.125/0.075mm) screeningcrushing products and analysis graded material particle size distribution, dissociativedistribution and metal grade distribution, the regularities distributed of Li and Co is theresearch focus. Particle size-0.25+0.125mm,-0.125+0.075mm and-0.075mm arerespectively analysised by SEM, XRD and EDS. The results shows that LiCoO2and elementCarbon mainly are enriched in-0.25mm, the percentage composition of them both more than90%, only a small amount of Cu, Al powder into-0.25mm graded.LiCoO2mainly focus in-0.25mm powder particles after crushing and screening process,LiCoO2and graphite particle surface are covered with PVDF binder and can not reach theexpected effect when flotation. Therefore, roasting process is necessary before flotationprocess. thermogravimetric curve shows that when roasting temperature up to660℃, andconstant temperature2hours, PVDF blinder can be removaled completely, which ensure thefollow-up processing smoothly.In flotation process, the main influencing factors include slurry concentration, collectingagent,foaming agent dosage, slurry pH value, agent dosage, aeration, stirring, flotation timeand water quality, among them, slurry concentration, collecting agent and foaming agent playthe leading role. Using Design-experts research the relationship of them, slurry concentration selection from4%to12%, the collecting agent and foaming agent were selected from0.2kg/tto3.2kg/t and0.07kg/t to0.21kg/t respectively. Results show that the slurry concentration isthe significant influencing factors in the flotation process.Design-experts shows that Orthogonal experiment attain optimal effection when slurryconcentration equal10%, collecting agent dosage equal0.2kg/t and foaming agent dosageequal0.2kg/t, the analyses indicate that LiCoO2grade can reaches92%, cobalt acid lithiumrecovery rate can attain93%, the credibility of the optimized combination is more than90%,which display the technology has excellence separation effect.