Zinc
Zinc (Zn) is brittle, but it becomes malleable at 100° C. Zinc, a blue-gray, metallic element, is a moderately good conductor of electricity. The most common alloy is brass, which is a mixture of zinc and copper.
Type
Element (Minerals/Ores of)
Mineral Classification
Sulfide
Chemical Formula
(Zn,Fe)S (sphalerite)
Mohs Hardness
3.5-4
Crystal System
Isometric
Color
Brown, yellow, red, green, black
Luster
Adamantine, resinous, greasy
Fracture
Uneven, conchoidal
Description
Zinc (Zn) is brittle, but it becomes malleable at 100° C. Zinc, a blue-gray, metallic element, is a moderately good conductor of electricity. The most common alloy is brass, which is a mixture of zinc and copper.
Relation to Mining
Zinc is recovered from a number of different zinc minerals. The most significant of these is sphalerite. Other minerals, such as smithsonite (ZnCO3, zinc carbonate), and zincite (ZnO, zinc oxide) are also zinc ores.
Zinc is also recycled from scrap.
Uses
Zinc alloys well with other metals resulting in stronger, harder metals. Brass, for example, is a mixture of copper and 20%-45% zinc.
Adequate amounts of zinc are essential to a healthy life in all humans and animals. It is necessary for the function of a number of different enzymes. It has also been proved necessary for skin and bone growth as well as sexual maturation. The body uses zinc to process food and nutrients. When animals do not have enough zinc in their systems, they need to consume 50% more food to match the weight gain of an animal with enough zinc in its body. About 0.003% zinc is needed for proper health.
Zinc is relatively non-reactive in air or water. Consequently, it is applied in thin layers to iron and steel products that need to be protected from rusting. This process is called galvanizing. Galvanizing is done in a number of ways. Generally, the metal is dipped in molten zinc. It can also be done by electroplating or by painting on a layer of zinc compound.
Zinc is used in making rubber and paint, chemicals, agricultural applications, in TV screens, fluorescent lights and for dry cell batteries. Pennies are made of zinc – with a thin coating of copper on top.
Zinc dust is used in the removal of impurities from solution in zinc electrowinning.
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