| 摘要 |
Improved production of pig iron is effected with lump lignite or sub-bituminous coal that have been heated in hot water or steam under elevated pressure sufficient so that water does not change into steam. High moisture content lignite and sub-bituminous coal, which normally cannot be used in blast furnaces because of slacking, are partially dried by this treatment. For example, lumps of lignite or sub-bituminous coal with moisture contents of 30% to over 50%, have the moisture content reduced to from about 15% to 25% by this treatment and shrink in size and become much harder so that they do not slack and can be used in conventional lump size in blast furnaces. The temperature of heating with water or steam is preferably about 210 DEG C to 218 DEG C. The blast furnace is preferably operated with oxygen and steam though preheated air may be used.
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