processes for dissolving and recovering at least one element from nb or ta and at least one other element from u or rare earth elements from ores and concentrates

摘要

Dissolution and recovery processes of at least one element from nb or ta and at least one other element from one or more rare earth elements from ores and concentrates The invention relates to a process for dissolving at least one element selected from niobium and tantalum and at least one other element selected from uranium and rare earth elements, advantageously for the dissolution of niobium, tantalum, uranium and rare earth elements present in ore or ore concentrate. the process comprises: - roasting material, comprising the above elements, whose material is mixed, dried or in the presence of water, with acid roasting agent to obtain calcine; the material consists of ore or concentrate or is obtained by ore or concentrate and the acid roasting agent provides roasting in sulphate medium; and - dissolving in calcine an aqueous solution to obtain sludge, the liquid fraction of which includes ferrous iron, at a concentration of at least 50 g / l, advantageously at least 70 g / l and most advantageously at least 120 g / l.