Strategy for coal-washing operations in New Mexico. [Two product streams and waste]
The loss of about one-fifth the heating values during coal preparation has generally precluded the washing of New Mexico stream coals, although a few washeries are planned for high-ash coals. Nevertheless, the utilization of a washery at new operations with a multiproduct strategy might offer an economic advantage. The proposed process would float 25% of the plus 5/16-inch coal at a specific gravity of about 1.35 resulting in a coal having 6% ash and 13,000 Btu/lb on a moisture-free basis. The sink coal would then be recleaned at 1.80 sp gr to reject a high-ash fraction (70%). The middlings, which would contain most of the heat value, would feed a mine-mouth power plant. An overall heat recovery of about 95% would result. This strategy would allow production of significant tonnages of clean coal that could be used for several purposes. First, the coarse fraction of the 6% ash, low-sulfur material would command a premium for firing industrial boilers. Its lower shipping cost per million Btu would offer considerable advantage to distant utilities. Finally, this clean material could be used to fire one unit of a multiunit mine-mouth plant resulting in significantly less pollution-control equipment for that unit. The feasibility of such a strategy would clearly depend on local conditions. For example, a utility-owned mine supplying a single-unit mine-mouth plant could not apply this strategy. However, an independent coal producer supplying primarily a large utility customer and also having excess production capacity should consider this strategy. Different mines in the same area supplying mine-mouth units and the other distant utilities might find a joint operation mutually beneficial.
- OSTI ID:
- 6324973
- Resource Relation:
- Related Information: Progress report 9
- Country of Publication:
- United States
- Language:
- English
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