Question

mining is used for extracting
mineral deposits present at great
depths.​

Answer 1

Answer:

Deep sea mining is a mineral retrieval process that takes place on the ocean floor. Ocean mining sites are usually around large areas of polymetallic nodules or active and extinct hydrothermal vents at 1,400 to 3,700 metres (4,600 to 12,100 ft) below the ocean’s surface.[1] The vents create globular or massive sulfide deposits, which contain valuable metals such as silver, gold, copper, manganese, cobalt, and zinc.[2][3] The deposits are mined using either hydraulic pumps or bucket systems that take ore to the surface to be processed.

As with all mining operations, deep sea mining raises questions about its potential environmental impact. Environmental advocacy groups such as Greenpeace and the Deep sea Mining Campaign[4] have argued that seabed mining should not be permitted in most of the world's oceans because of the potential for damage to deepsea ecosystems and pollution by heavy metal laden plumes.

Answer 2

Answer:The primary methods used to extract minerals from the ground are:  

Underground mining

Surface (open pit) mining

Placer mining  

The location and shape of the deposit, strength of the rock, ore grade, mining costs, and current market price of the commodity are some of the determining factors for selecting which mining method to use.

Higher-grade metallic ores found in veins deep under the Earth’s surface can be profitably mined using underground methods, which tend to be more expensive. Large tabular-shaped ore bodies or ore bodies lying more than 1,000 feet (300 m) below the surface are generally mined underground as well. The rock is drilled and blasted, then moved to the surface by truck, belt conveyor, or elevator. Once at the surface, the material is sent to a mill to separate the ore from the waste rock.

Lower grade metal ores found closer to the surface can be profitably mined using surface mining methods, which generally cost less than underground methods. Many industrial minerals are also mined this way, as these ores are usually low in value and were deposited at or near the Earth’s surface. In a surface mine, hard rock must be drilled and blasted, although some minerals are soft enough to mine without blasting.

Explanation: