Article: Recovery Process of Li, Al and Si from Lepidolite by...

Article:
Recovery Process of Li, Al and Si from Lepidolite by Leaching with HF Gustavo D. Rosales, Eliana G. Pinna, Daniela S. Suarez and Mario H. Rodriguez * Laboratorio de Metalurgia Extractiva y Síntesis de Materiales (MESiMat), Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo, Mendoza 5500, Argentina; [email protected] (G.D.R.); [email protected] (E.G.P.); [email protected] (D.S.S.) * Correspondence: [email protected]; Tel.:+54-9261-337-9329 Academic Editor: William Skinner Received: 5 January 2017; Accepted: 1 March 2017; Published: 3 March 2017

4. Conclusions In summary, a process that includes leaching with HF was employed to extract Li, Al and Si from lepidolite. The experimental results indicate that the optimal conditions to achieve a Li extraction higher than 90% are: solid-liquid ratio, 1.82% (w/v); temperature, 123 °C; HF concentration, 7% (v/v); stirring speed, 330 rpm; and reaction time, 120 min. The compounds K2SiF6 and Na3AlF6 can be obtained as subproducts of the process, with a recovery of 93% and 95%, respectively. The Li dissolved can be separated by chemical precipitation as LiF, with a recovery value of 92% and a purity of 99.1%. Furthermore, Al and Si are recovered as valuable subproducts, diminishing the generation of residues during the process. The results of the current work can provide a simple, economic and effective way to recover Li from lepidolite.

Interesting that Lepidico have a process and offtake in place also.

Anyway RC and DD from Kanuka and Kitotolo pending.