PROCEDE DE PURIFICATION DU NIOBIUM ET/OU DU TANTALE

摘要

The present invention relates to a method for purifying niobium and/tantalum from an ore or a concentrate of niobium and/tantalum containing titanium and/or iron, wherein the method includes the following steps: a) the sodium conversion of an ore or a concentrate of niobium and/tantalum containing titanium and/or iron by adding a concentrated NaOH solution at a temperature of 50°C to 150°C; b) the solid/liquid separation and recovery of the solid obtained in step a); c) washing the solid recovered in step b) using an aqueous solution containing at most 30g/L of NaOH and recovering the washed solid; d) adding water in order to dissolve the niobium and/tantalum; e) the solid/liquid separation and recovery of the aqueous solution containing the niobium and/tantalum obtained in step d); f) acidifying the aqueous solution obtained in step e) up to a pH of 1 to 5, advantageously between 3 and 4 in order to precipitate the niobium and/tantalum; and g) the solid/liquid separation and recovery of the purified precipitate of niobium and/tantalum obtained in step f).