Tin be toxic. Tin in combination with other elements forms a wide variety of useful alloys. Tin is most commonly alloyed with copper. Pewter is 85–99% tin; bearing metal has a high percentage of tin as well. Bronze is mostly copper (12% tin), while addition of phosphorus gives phosphor bronze. Bell metal is also a copper–tin alloy, containing 22% tin. Tin has sometimes been used in coinage; for example, it once formed a single-digit percentage (usually five percent or less) of American and Canadian pennies. Because copper is often the major metal in such coins, sometimes including zinc, these could be
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