Removal of pyrite and trace elements from waste coal by dissolved-CO{sub 2} flotation and chelating agents. Final technical report, September 1, 1993--August 31, 1994
- Babcock and Wilcox Co., New Orleans, LA (United States)
- Illinois Clean Coal Inst., Carterville, IL (United States)
The overall objective of this project was to use ultrafine bubbles generated by dissolved C0{sub 2} to recover useable fuel, and reject pyrite and other minerals from a waste coal in flotation. In addition, a chelating agent was used to remove trace metals from the froth products. Illinois No. 6 waste coal obtained from a refuse thickener of a coal cleaning circuit was used as the feed in flotation. The as-received waste coal had a top size of 2400 microns. The waste coal was ground to {minus}75 microns ({minus}200 mesh) and {minus}44 microns ({minus}325 mesh). The as-received and the ground waste coal samples were subjected to flotation. Dissolved-CO{sub 2} flotation tests were performed mainly in a 3-inch diameter by 8 feet high packed column under various test conditions. Some tests were also performed in a 2-inch diameter microbubble column for comparison. The flotation performance of the waste coal in the microbubble column was higher than that for the packed column. The packing in the packed column hindered the coal flotation. The separation efficiency of the ground coal was less than that for the asreceived coal. Flotation of the waste coal was also performed in the packed column using coarser bubbles generated by dispersed C0{sub 2} and air. The separation efficiency of the ground waste coal of 44 microns top size was higher than that for dissolved-CO{sub 2} flotation. Additives were used to modify the waste coal surfaces. Triton-X 100, a nonionic surfactant and EDTA, a chelating agent, increased the separation efficiency of the waste coal.Most of the trace metals in coal were reduced in different degrees by flotation. Triton X-100 or EDTA enhanced removal of chromium, nickel, and selenium. Applying EDTA to the froth products further removed lead significantly.
- Research Organization:
- Illinois Dept. of Energy and Natural Resources, Springfield, IL (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- FC22-92PC92521
- OSTI ID:
- 10115131
- Report Number(s):
- DOE/PC/92521-T193; ON: DE95005564; BR: AV0100000/AV0102000
- Resource Relation:
- Other Information: PBD: [1994]
- Country of Publication:
- United States
- Language:
- English
Similar Records
Physical cleaning of waste coal by dissolved-CO{sub 2} flotation. Final technical report, September 1, 1992--August 31, 1993
PDU-scale testing of microbubble flotation