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Title: Bench-scale development of the TRW process for cleaning coal (gravimelt process). Quarterly technical progress report, November 1983-February 1984

Technical Report ·
DOI:https://doi.org/10.2172/5190950· OSTI ID:5190950

This report presents progress for the second quarter of performance on Contract Number DE-AC22-83PC63032. The effort includes Tasks 6 through 13 of a continuing program to demonstrate the TRW Gravimelt coal cleaning technology. The technical effort this quarter has concentrated on defining an operable flow scheme, conducting the required supporting laboratory tests and establishing the performance of the bench scale centrifuge. Key to directing the development and scale-up activity, was the definition of the process flow scheme. Based on laboratory studies of the reaction and the washing/separation steps, it was concluded that a counter-flow reactor system was needed to make the separation of mineral-rich caustic from the processed coal. The absence of mineral matter should also improve the filtration of the processed coal. Each of the steps have been reviewed to determine where industry experience with similar operations may be able to reduce development effort or increase confidence. Laboratory testing has established the general effect of impure caustic on the reaction rate and extent of ash and sulfur removal. The bench-scale centrifuge was used to concentrate processed coal from caustic slurries in the range of 2 to 5% coal in 5 to 15% aqueous caustic. Centrifuge cakes generally were thick pastes with 35 to 40% solids. The first test of a slurry of about 20% coal in aqueous caustic also gave about a 35% solids product. Laboratory tests showed that concentration by filtration would have been very slow, probably as a result of gelatinous precipitates from the used caustic. 1 figure, 5 tables.

Research Organization:
TRW, Inc., Redondo Beach, CA (USA)
DOE Contract Number:
AC22-83PC63032
OSTI ID:
5190950
Report Number(s):
DOE/PC/63032-T1; ON: DE84009698
Resource Relation:
Other Information: Portions are illegible in microfiche products. Original copy available until stock is exhausted
Country of Publication:
United States
Language:
English