Tin sources and trade in ancient times Bantu culture of Zimbabwe are known to have actively mined, smelted and traded tin between the 11th and 15th centuries AD . Tin deposits exist in many parts of South America, with minor deposits in southern Peru, Colombia, Brazil, and northwestern Argentina, and major deposits of exploitable cassiterite in northern Bolivia. These deposits were exploited as early as 1000 AD in the manufacture of tin bronze by Andean cultures, including the later Inca Empire, which considered tin bronze the "imperial alloy". In North America, the only known exploitable source of tin during ancient times is located in the Zacatecas tin
Sundown Tin and Copper Mine to calcine the tin concentrates and drive of arsenic and sulphur. In 1917 a Merton calciner was erected and flues for arsenic recovery constructed. It is likely that these replaced the old reverberatory furnace and calciner. Arsenic became and important product of the mines, the demand escalating during the prickly pear infestation. New shafts were sunk at both the tin and copper mines. The lack of water reduced output in 1918, only 23 tons of tin and 12.5 tons of copper concentrates being produced, but the new shafts were continued, the three compartment copper shaft having poppet legs and ore