Low-cost metal adsorbents from lignite
- Grand Forks Activation Technologies, ND (United States)
- Univ. of Kentucky, Lexington, KY (United States). Center for Applied Energy Research
Current technologies to remove heavy metals from acidic waters tend to use lime and/or caustic soda to create a highly basic solution which causes the metals to precipitate as a metal hydroxide rich sludge which must then be disposed of as a waste. The proposed process would treat streams containing low levels of metal contaminants in a simple lignite bed to remove cationic heavy metal ions. For more acidic streams, the acidity of the water could first be moderately reduced with landfill sludge (Ca-sludge) followed by lignite treatment to remove and immobilize metals. This type of processing would need a conventional mixing settling tank configuration. Tests have been performed which indicate minus 14 mesh lignite has the highest capacity to remove metal ions from solution. One wt% of lignite reduced the zinc content of a lab solution from 95 ppm to 7 ppm (5 wt% reduced it to 0.5 ppm). The combination of 1 wt% lignite and 0.1 wt% Ca-sludge reduced the zinc content of a mine water sample from 36 to 10 ppm (0.5 wt% of Ca-sludge gave 2 ppm of Zinc) while increasing the solution pH from 3.84 to 7.20. These results indicate that optimum treatment rates would be between 1--2 wt% of lignite and 0.1 to 0.5 wt% of Ca-sludge. A lignite to Ca-sludge ratio of about 10 to 1 should be a sulfur emission compliant combustion fuel.
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- OSTI ID:
- 504675
- Report Number(s):
- CONF-960954-; TRN: IM9733%%90
- Resource Relation:
- Conference: 13. annual international Pittsburgh coal conference, Pittsburgh, PA (United States), 3-7 Sep 1996; Other Information: PBD: 1996; Related Information: Is Part Of Thirteenth annual international Pittsburgh coal conference: Proceedings. Volume 1; Chiang, S.H. [ed.]; PB: 786 p.
- Country of Publication:
- United States
- Language:
- English
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