|
|
|
|---|
| Minerals include such substances as copper, gold, iron, lead, and salt. Industries use minerals to manufacture countless products. |
 |
|---|
When these are depleted, mining companies turn to lower-grade and harder-to-mine ores. Many such deposits require advanced technology and large amounts of energy to mine. Some take so much energy to mine and refine that they cannot be profitably developed.
Deposits of minerals are unevenly distributed around the world. This uneven distribution of minerals has played a major role in history. For example, the ancient Romans battled the Celts for control of the tin mines in southern England. A desire for gold was largely responsible for the Spanish explorations and conquests of many parts of the New World.
The need for minerals continues to influence international relations today. Many countries must import large amounts of various minerals. The United States, for example, imports almost all of the sheet mica and strontium it uses. In addition, the United States imports more than half of its chromium, cobalt, fluorine, manganese, nickel, platinum, and tin.
Mining and refining minerals often destroys scenic lands and habitats for animals and plants. It can also pollute air and water. One method of copper mining, for example, leaves large open pits on the surface of the land. Fumes from copper smelters, iron and steel mills, and other refineries pollute the air and kill many plants. Some refineries discharge wastes in lakes and streams.
We can conserve minerals in a number of ways. Industries can reduce waste by using more efficient mining and processing methods. In some cases, industries can substitute plentiful materials for scarce ones. Some mineral products can be recycled. Aluminum cans are commonly recycled. Although bauxite is plentiful, it can be expensive to refine. Recycling aluminum products does not require the large amounts of electric power needed to refine bauxite. Products made from many other minerals, such as nickel, chromium, lead, copper, and zinc, can also be recycled. Next >>> |
|---|
.. . |
|
||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
||||||||||||