4. Scandium pre-concentration methods

The aim of pre-concentration for scandiferous minerals or scandium in solution, prior to extraction of the scandium metal, is to reject sterile gangue or depleted liquors of little economic interest. This not only saves energy and reagents, but also reduces the cost of the metallurgical investment.

Broadly speaking, there are three possible situations:

• pre-concentration is possible by physical means, as is the case for thortveitite ores and old mining waste containing carrier minerals (table 1 ). Scandium-enriched pre-concentrates are obtained by conventional mineralurgy techniques (gravity, magnetism, electrostatics, flotation);