Development of alternate process flowsheets to recover an unconventional resource rare earth bearing placer garnet and sillimanite from Southeast Coast of India

Abstract

In the present study unconventional resources bearing rare earth mineral garnet and sillimanite have been attempted to recover using different alternate flowsheets. The best commercial grade garnet and sillimanite products are obtained from total heavy mineral concentrate recovered by using a spiral concentrator. The garnet product obtained after cleaning with spiral followed by a magnetic separator has a garnet grade of 98.8%, with a recovery of 97.2% and 4.13% overall yield from the bulk sample containing 4.5% garnet. In case of sillimanite also the spiral material is cleaned with a magnetic separator and followed by flotation yields a sillimanite material containing 98.6% sillimanite grade, with a recovery of 95.3% and an overall yield of 3.9% from most feed sample contain 4.0% sillimanite. Therefore, it is recommended to use gravity to remove the gangue ore before it enters the concentrator and to use magnetic equipment for garnet and flotation to obtain commercial grade sillimanite. Rare earth elements can be recovered from this level of garnet and sillimanite.