powdered refractory material
31Cementation process — The cementation process is an obsolete technique for making steel by carburization of iron. Unlike modern steelmaking it increased the amount of carbon in the iron. It was apparently developed before the 17th century. OriginsThe process probably… …
32Dolaucothi Gold Mines — The Dolaucothi Gold Mines (grid reference SN662403), also known as the Ogofau Gold Mine, are Roman surface and deep mines located in the valley of the River Cothi, near Pumsaint, Carmarthenshire, Wales. The gold mines are located within the… …
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