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,
Group 5 element magnesium. 230,000 metric tons of niobium ore are produced yearly, with Brazil producing metric 210,000 tons, Canada producing 10000 metric tons, and Australia producing 1000 metric tons. 60000 metric tons of pure niobium are produced each year. 70000 metric tons of tantalum ore are produced yearly. Brazil produces 90% of tantalum ore, with Canada, Australia, China, and Rwanda also producing the element. The demand for tantalum is around 1200 metric tons per year. Dubnium is produced synthetically by bombarding actinides with lighter elements. Vanadium's main application is in alloys, such as vanadium steel. Vanadium alloys are used in springs, tools,