Abstract: Niobium and tantalum containing pyrochlore is recovered from high silicate gangue content ore with good selectivity and yield employing collectors of formula ##STR1## wherein R.sub.1, R.sub.2 and R.sub.3 are independently 8 to 16 carbon straight or branched chain alkyl groups, at pH 1.5 to 6.5.

Abstract: Direct flotation of pyrochlore from its ore can be carried out at acidic pH using 1-amidoethyl-2-substituted imidazolines of the formula ##STR1## wherein R and R' are independently alkyl or alkenyl of 8 to 22 carbons, or their salts. In the presence of large amounts of carbonate in the ore, the pulp is acidified with hydrofluoric acid, fluosilicic acid, or their acid reacting compounds. Using this process, pyrochlore concentrates can be obtained by direct flotation from ore containing 0.1% or more of sulphide compounds calculated as FeS.sub.2.