THE ROLE OF INORGANIC AND ORGANIC-REAGENTS IN THE FLOTATION SEPARATION OF RARE-EARTH ORES

The relative adsorption of chemisorbing fatty acid collectors at high temperatures, together with the addition of soda ash modifier and lignin sulfonate depressants, is the key to the industrial processing of carbonatite-type rare-earth ore deposits. A detailed study was made using solution equilibria, electrokinetic measurements, adsorption investigations, microflotation and batch flotation tests to delineate the nature of surface interactions of various reagents with the different mineral constituents of a typical bastnaesite type rare-earth ore. Flotation plant results are interpreted in terms of reagent adsorption mechanisms, and the role of temperature in achieving the desired selectivity has been established. The results also indicate the superiority of alkyl hydroxamate collectors for the beneficiation of these types of rare-earth deposits containing barite and calcite as the typical gangue minerals.