Servizio Comunitario di Informazione in materia di Ricerca e Sviluppo - CORDIS

Separation processes for treating chromite ores

Separation processes were tested for the potential exploitation of low grade, difficult to treat Greek chromite deposits. With respect to magnetic separation, heating to 200 C could result in a efficient beneficiation. Taking into account the difference between specific gravity of chromite and its gangue ore, the magneto-gravimetric separation could be applied. For selective grinding using surface acting reagents, some of the substances tested can be succesfully used as grinding aids in laboratory experiments. However, it is not certain yet that these substances have the same positive effects in a continuous mill industrial application. Using dynamic dense media separation, the chromite ores can be treated successfully in a dense media plant by a tri-flo separator producing final chromite ores concentrates or pre-concentrates for further treatment. Ores can be treated successfully by gravimetric separators and the chromite ores can be treated successfully by cell flotation producing marketable concentrates of high chromium content. Different procedures are needed for different types of gangue material that accompany chromite. Column flotation showed no improvement but multi gravity separation was a very efficient way to recover fine chromite particles. High quality concentrates are produced with interesting recoveries.