Calamine brass Calamine brass Calamine brass is brass produced by a particular alloying technique using the zinc ore calamine directly, rather than first refining it to metallic zinc. Direct zinc smelting appears to have been unknown in Europe until the mid-18th century, even though the alloyed calamine brass was in use for centuries, and metallic zinc was produced directly via reducing-atmosphere smelting in India and China from the 12th century CE onwards. Brass is an alloy of copper and zinc and, when it was first developed, methods for producing metallic zinc were unknown. Metallurgists wishing to produce brass thus used calamine (actually
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,