FLOTATION CONCENTRATION OF A XENOTIME PRE-CONCENTRATE

The world market for rare-earths elements is increasing due to the dev elopment of new products and applications, resulting in the need for t echnology to treat deposits having highly complex mineralogy, such as that of Pitinga, AM, Brazil, with estimated reserves of 146,960 t of r are-earths oxides (REO), including Y2O3. Mineralogically the mine of P itinga is very rich. The initial and major target of the company Paran apanema was the production of tin concentrates from placer deposits an d later from primary ore. However, geological studies identified sever al other minerals of potential economical importance, such as: columbi te-tantalite, zircon, cryolite and xenotime, the objective of the pres ent investigation. The response of a pre-concentrate sample of the non -conducting fraction from Pitinga's electrostatic separator to laborat ory scale physical concentration methods was very poor. Another possib ility for the selective separation of xenotime and zircon (the major a ssociated mineral) is flotation. Microflotation experiments were perfo rmed in a modified Hallimond tube with pure samples of xenotime and zi rcon, in the presence of hydroxamate as collector and five different r eagents as depressants. The zeta potential of xenotime and zircon was determined in the presence of supporting electrolyte and hydroxamate. (C) 1997 Elsevier Science Ltd.