Cementation process in the 1740s. In the early modern period, brass, an alloy of copper and zinc, was usually produced by a cementation process in which metallic copper was heated with calamine, a zinc ore, to make calamine brass. Cementation process The cementation process is an obsolete technology 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. Derwentcote Steel Furnace, built in 1720, is the earliest surviving example of a cementation furnace. Another example in the UK is the cementation furnace in Doncaster Street,
Ore Mountains last silver mines closed and the company was disbanded. Mining in the Ore Mountains was given new life during the First and Second World Wars in order to supply raw materials. The Third Reich also saw the resumption of silver mining. Afterwards the people returned to the manufacture of wooden products and toys, especially in the Eastern Ore Mountains. The clock industry is centred on Glashütte. In the Western Ore Mountains, economic alternatives were offered by the engineering and textile industries. In 1789 the chemical element uranium was discovered in St. Joachimsthal; then in pitchblende from the same area, radium