Coral polyps also use the energy supplied by their symbiotic algae to produce calcium carbonate, or limestone. They secrete the limestone from their base, creating a protective skeleton and a hollow chamber called a cup. The polyps retreat into their cup to hide when predators come looking for them.
Uranium is mined where there are concentrations in the earthâs crust. More than half of the worldâs uranium comes from mines in Canada, Australia and Kazakhstan.Other major producers are the United States, South Africa, Namibia, Brazil, Niger and Russia.Many more countries have smaller deposits that could be mined if needed.ore than half of the worldâs uranium comes from mines in Canada, Australia and Kazakhstan. Other major producers are the United States, South Africa, Namibia, Brazil, Niger and Russia. Many more countries have smaller deposits that could be mined if needed.
Copper is mined mostly in open pit mines, such as those found in Utah, New Mexico, and Chile. Chile produces the largest percentage of the world's copper with nearly 33% of the world's export. Copper is also found in the U.S., Indonesia, and Peru. Although copper has been used for thousands of years about 95% of all extracted copper was mined within the last hundred. In addition to the many mines found all over the world much of the copper we use has been recycled.