TECHNICAL NOTE ADSORPTION OF OLEATE AND OCTYL-HYDROXAMATE ON TO RARE-EARTHS MINERALS

The adsorption of sodium oleate and potassium octyl-hydroxamate onto t he rare-earths minerals monazite and bastnaesite was investigated thro ugh microflotation experiments, zeta potential determinations and infr ared spectroscopy. The monazite and bastnaesite samples were purified in the laboratory reaching, respectively, final grades of 68.7 and 45. 3% RE(2)O(3) + ThO2. The results confirm that sodium oleate chemisorbs onto bastnaesite and suggest a physical adsorption mechanism of this reagent onto monazite. Despite the lack of a full confirmation from FT IR spectrometry, there is a possibility of oleate chemisorption onto m onazite in the pH range above the isoelectric point. A chemical adsorp tion mechanism was established for the interaction between octyl-hydro xamate and both minerals.