burnt shale

British  

noun

1. carbonaceous shale formed by destructive distillation of oil shale or by spontaneous combustion of shale after it has been some years in a tip: sometimes used in road making

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Example Sentences

Cemex officials said the company plans to lower emissions in part by using clinker substitutes that are byproducts of other industrial processes, such as burnt shale oil or glass furnace slag.

From Reuters • Jul. 1, 2021

Of these, oyster or marine shells, burnt shale, and slag are most common.

From American Rural Highways by Agg, T. R. (Thomas Radford)

Its base consists almost entirely of pumice, in which are included fragments of basalt and other lavas, pieces of burnt shale, slate, and sandstone, and numerous trunks and branches of trees.

From The Student's Elements of Geology by Lyell, Charles, Sir

Fifty tons of this burnt shale are required to make one ton of alum.

From A Month in Yorkshire by White, Walter