Study on the Treatment of Liquid Waste from Rare Earth Processing by Chemical Precipitation

Tin Moe Hlaing, Aye Thi Tar, Thant Zin Myo, Bo Bo Mya Win


This paper describes treatment of liquid waste from rare earth processing by chemical precipitation. Monazite ore from Moemeik Myitsone area was used as raw material for rare earth processing. Large amount of solid and liquid wastes were generated after rare earth oxide processing. Solid waste was stored in the storage tanks and liquid waste needed further treatment before discharges to the environment. Research process serves the purpose of reducing the volume of the waste as much as possible to protect men and the environment from any undesirable effects for the present and future generation. Treatment methods are selected based on the composition, quantity and form of the waste materials. The used method is chemical precipitation method. For liquid waste treatment, the most coagulation treatment used is the Fe +++ co-precipitation followed by settling, decantation and filtration of the supernatant liquid. The efficiency of the process can be improved by careful control of the pH and the settling the decantation procedure. The sludge was filtered, dried in oven and collected in plastic bags and temporary stored in 100 liters plastic drums.   Finally all of the decontaminated effluents are safety discharged to the environment. All of the experiments were analyzed by the X- ray Fluorescence Spectrometer (XRF). Before treatment, thorium and uranium contained <2000 ppm,  < 300 ppm and this is in the low level waste. After treatment result in decant water gives uranium (< 1 ppm) and thorium (< 10 ppm).

According to the threshold limits for the UK radioactive classification system,   liquid waste from rare earth processing was less than (0.4 Bq/g) and this range is in exempt waste and can be discharge to drain and to the environment safety. The safety regime was in place and improved simultaneously by survey monitoring by using Alert Monitor 4 meter Scale in USV/H.


rare earth processing; chemical precipitation; coagulation; co-precipitation; settling; decantation; filtration; decontaminate; effluents; sludge; discharge; x-ray fluorescence spectrometer; alert monitor.

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Gupta CK., Krishnamurty. N. Extractive Metallurgy of Rare Earths, CRC Press, 2005

C. A. Mawson, Management of Radioactive Wastes, 1965

P.M.B. Pillai, Naturally Occurring Radioactive Material (NORM) in the Extraction and Processing of Rare Earths, Proceedings of an International Symposium Seville, IAEA, Spain, 19-22 March 2007

Meor Yusoff M.S and Latifah A., “ Rare Earth Processing in Malaysia: Case Study of ARE and MAREC plants,” the Proceeding of the Regional symposium on Environment and Natural Resource 10-11th April 2002, vol:1: 287-295

Lee Bell BA MA (ESD), Rare Earth and Radioactive Waste, A Preliminary Waste Stream Assessment of the Lynas Advanced Materials Plant, Gebeng, Malaysia, 2011

International Atomic Energy, Treatment of Alpha Bearing Wastes, Technical Reports Series No.287, IAEA Vienna, 1988

R. H. Burns, J.H. Clarke, T.D. Wright and J. H. Myatt United Kingdom, Present Practices in the treatment of Liquid Wastes at the Atomic Research Establishment, Harwell, Proceedings of a Symposium, IAEA Vienna, 1965

D. J.KVAM, University of California, USA, Waste Management Practices at Lawrence Radiation Laboratory, Proceedings of a Symposium, IAEA Vienna, 1965


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