| Abstract |
During the geological prospecting works conducted in 2013 on Bangka Island (Indonesia), high monazite content was identified in the wastes produced during processing of cassiterite deposits. Monazite, among 250 known minerals containing REE, is one of the most important minerals as primary source of REE:rhe monazite content in this waste is up to 90.60%. The phase composition of the investigated tailing proves that the sources of minerals accompanying the placer sediments tin mineralization are granitoids. The tailing is composed of numerous ore minerals, including monazite, xenotirne, zircon, cassiterite, malayaite, struverite, aeschynite-(Y), ilmenite, rutile, pseudorutile and anatase. Monazite grains belong to the group of cerium monazite. Its grains are characterized by high content of Ce2O3 27.12-33.50 wt.%, La2O3 up to 15.46 wt.%, Nd2O3 up to 12.87%. The total REE2O3 + Y content ranges from 58.18 to 65.90 wt.%. Monazite grains observations (SEM-BSE) revealed the presence of porous zones filled with fine phases of minerals with U and Th content. The radiation intensity of Th-232 is A(Th) = 340 +/- 10 Bq and (238)A(U) = 114 +/- 2 Bq. High content of monazite and other REE minerals indicates that tailing is a very rich, potential source of REEs, although the presence of radioactive elements at the moment is a technological obstacle in their processing and use. The utilization of monazite bearing waste in the Indonesian Islands can be an important factor for development and economic activation of this region and an example of the good practice of circular economy rules. |
