Tests of alkaline addition to coal mine spoils for prevention of acid mine drainage
- Pennsylvania State Univ., PA (United States)
Addition of limestone or lime products to spoil during surface mining of coal has been widely proposed in recent years, but with some apparent failures and a lack of careful documentation of successes vs. failures. This paper summarizes tests of the method at three scales. Lab tests with 1 kg samples showed that lime kiln flue dust completely prevented acid generation from shale with 7% pyritic sulfur, and limestone markedly decreased but did not prevent acid generation. At the Kauffman Mine of Al Hamilton Contracting Co. in Clearfield Co., PA, with support from PA Energy Development Authority, a mine-scale test of lime addition shows satisfactory water quality in a backfill well within the spoil. The application of a special handling procedure for the alkaline addition is believed to be a major factor in the positive results received to date. Also at this site, five test cells containing about 400 tons each of spoil with 2% pyritic sulfur had different amounts of lime added. Results to date indicate that lime addition markedly decreases AMD, but that delays in mixing lime with newly broken overburden or incomplete mixing to leave portions of spoil unlimed can allow microenvironments of acid generation to develop; the resulting AMD generation process may take some time to stop.
- OSTI ID:
- 51974
- Report Number(s):
- CONF-940930-; TRN: IM9524%%444
- Resource Relation:
- Conference: 11. annual international Pittsburgh coal conference: coal, energy and the environment, Pittsburgh, PA (United States), 12-16 Sep 1994; Other Information: PBD: 1994; Related Information: Is Part Of Eleventh annual international Pittsburgh coal conference proceedings: Volume 2; Chiang, S.H. [ed.]; PB: 860 p.
- Country of Publication:
- United States
- Language:
- English
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