Which method of metal refining is generally used when a metal of high degree of purity is needed?
Give one example where hydro-metallurgy is used for metal extraction.
Extraction of silver from its ore.
What is the major role of fluorospar (CaF2) which is added in small quantities in the electrolytic reduction of alumina dissolved in fused cryolite?
Ultra pure silicon is needed by electronic industry. By which method of refining, such a high purity silicon is obtained?