Extraction
Unlike conventional brick-making clay, some fire clays (especially flint clays) are mined at depth, found as a seatearth, the underclay associated with coal measures.
Read more about this topic: Fire Clay
Famous quotes containing the word extraction:
“Logic is the last scientific ingredient of Philosophy; its extraction leaves behind only a confusion of non-scientific, pseudo problems.”
—Rudolf Carnap (1891–1970)