lignite(Coal of relatively recent origin consisting of accumulated layers of partially decomposed vegetation, intermediate between peat and bituminous coal; often contains patterns from the wood from which it formed)
lignite mining(Extraction of brown coal from natural deposits; lignite is a brownish-black solid fuel in the second stage in the development of coal. It has a little over half the heating value of bituminous or anthracite coal)
lime(Any of various mineral and industrial forms of calcium oxide differing chiefly in water content and percentage of constituent such as silica, alumina and iron)