Pressure leaching of niobium and tantalum from columbo-tantalites

摘要

The extraction of Nb and Ta from a columbo-tantalite of San Luis, Argentina, is being studied by using apressure reactor and HF as leaching agent. The reagents andproducts have been characterized by several techniques suchas scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDXS), X-ray fluoroscence (XRF), X-raydiffraction (XRD), surface area (BET) and size particleanalysis. Experimental results have shown that the extractionof niobium and tantalum increases with increasingtemperature, reaction time and acid concentration. Forparticle size between +80 and –355 mesh no significantchanges are detected. It is also slightly affected by the stirringspeed. XRD analysis of the residues did not show formation ofnew crystalline structures.