Abstract:
The present investigation deals with the development of a process flow sheet for recovering strategic mineral monazite concentrate from a lean-grade offshore placer deposit of the Bramhagiri coast along the southeast coast of Odisha, India.In the present study, both dry and wet processes are investigated to improve the recovery and purity of monazite. The results of the pre-concentration studies reveal that by using multi-stage spiral concentrators, the Total Heavy Minerals [THM] have been upgraded to 97.8% with a monazite content of 0.33% from a feed sample containing 4.72% total heavy minerals and 0.01% monazite content. The beneficiation studies revealed that the feed was initially subjected to a high-tension separator, and the non-conducting fraction of the high-tension roll was further subjected to magnetic separation. The magnetic product was again subjected to a flotation process followed by cleaning of the flotation product using a magnetic separator. This magnetic product contains 98.89% monazite with 84% recovery and 0.28% yield from a spiral product containing 0.33% monazite and qualifies for extracting rare earths. It is worth recovering monazite mineral from even lean-grade deposits, as it is a source of uranium, thorium, and rare earth elements and is very high in demand for humankind due to technological advancements. In view of this, monazite recovery is not to be considered for the economic profitability of the process but for strategic requirements.