Leaching Kinetics of Aluminum from Alkali-Fused Spent Cathode Carbon Using Hydrochloric Acid and Sodium Fluoride

Abundant carbon resides in spent cathode (SCC) of aluminum electrolysis and its high-purity powder is conducive to high-value recycling. The alkali-fused SCC was separated effectively purified using an HCl/NaF solution. Effects particle size, leaching temperature, time, initial acid concentration, sodium fluoride dosage, on the purity removal rate, were investigated. Using as research object, kinetics examined by single-factor experiments. Results showed that under 4 M HCl size D(50) = 67.49 ?m, liquid-solid ratio 15:1, 333 K, 120 min, 0.3 NaF, with ash level below 1% obtained subsequent purification SCC. process described Avram equation, model characteristic parameter 0.75147 apparent activation energy 22.056 kJ/mol, which indicated a mixed control mechanism between chemical reactivity diffusion. kinetic reaction equation from system established.