Mineral Resources and the Threats of Mining

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The wealth of a nation depends on the natural resources it has. These resources may be Forest, Water, Land, Plants, Minerals, etc. These resources contribute to the economic development of the nation. But, this might lead to the total depletion of the resources. Hence proper strategies should be followed to conserve the resources.

MINERALS

Mineral resources are the backbone of the economic growth of a nation. They are found in the earth as ore. They are mined and run through various metallurgic processes and purified. Minerals are often called ‘stock’ or ‘non-renewable’ resources. Minerals form the base of all economic, industrial and commercial activities. The minerals sources can be either terrestrial or marine.

Terrestrial Mineral Resources

The terrestrial mineral resources are distributed in the earth’s crust. Chief among these is the ore that are used on a large scale to yield metals like Iron, Aluminium, Copper, Silver, Gold, Platinum, etc. There are also few minerals that are required in fewer amounts such as Vanadium, Tungsten, and Molybdenum.

Each mineral is confined to a particular region of the earth. For instance, North America is well supplied with the ore of Molybdenum, whereas Asia is rich in Tin, Tungsten, and Manganese. Cuba and North Caledonia have half of the world’s reserve of Nickel. Zaire is rich in Industrial Diamonds.

Marine Mineral Resources

Marine mineral resources can be divided into three categories based on a source.

  1. Minerals dissolved in water.
  2. Sediments present on the sea-bed.
  3. Those present at some depths below the sea-floor.

Magnesium and Bromine are being extracted from the marine source. The deep sea basins are found to contain enormous quantities of minerals such as Manganese, Nickel, Cobalt, and Copper. But their extraction is not economically feasible.

Based on the chemical nature marine minerals can also be divided into three categories. They are

  1. Terrigenous Minerals: This group constitutes minerals such as Ilmenite, Monazite, and calcareous minerals. Ilmenite is the primary source of Titanium, which is used in supersonic aircraft. Monazite is a chief source of Thorium, which is used in nuclear reactors.
  2. Biogenous Deposits: They occur along the ocean floor. They constitute shell pieces and skeletal debris of marine organisms. They are the primary source of Calcium carbonate.
  3. Chemogenomics Deposits: These are Manganese nodules. They also constitute of Nickel, Cobalt, and Copper.

 USES OF MINERAL RESOURCES

Mineral resources form the base of all industrial, economic and commercial activities.

  1. Coal and Oil are used as fuels and are used to generate electricity.
  2. Atomic minerals such as Uranium and Thorium are used in power generation
  3. Minerals such as Gypsum, Lime-Stone, Phosphate, and Sulfur are used in agriculture field as fertilizers or soil conditioners.
  4. Silica Chips used in the computers are made of Silica mineral.
  5. Diamond, Gold, and Platinum are used as ornaments.

EXPLOITATION OF THE MINERAL RESOURCES

Depending upon the condition of the terrain and depth of the ore deposits, two main types of the mining operation is carried out.

  1. Open cast mining or quarrying: To extract shallow mineral deposits.
  2. Underground mining: To recover deeper minerals.

Minerals found in the river and beach sand are normally worked by pumping or dredging of mineral-bearing sand. The fossil fuel oil is extracted from the ground using drilling operations. The ore-dressing process involves crushing the ore and separating valuable minerals from the ore by gravitation, flotation, etc. Valley side minerals are mined through tunnels driven into hillside areas.

ENVIRONMENTAL IMPACTS OF EXTRACTING MINERALS

Each step in mining and processing of minerals produce several environmental effects. Many waste effluents are released into the atmosphere during mining. Certain facts are as follows.

  1. To recover minerals, large volumes of forests are removed. Hence, deforestation has been taken place to a large extent.
  2. In open cast mining, a great volume of debris is generated, and they disrupt the surface and ground water circulation. Hence resulting in the channel capacity of the streams present very close to mining areas.
  3. Mining mainly causes air pollution.
  4. The acid water generated by oxidation of pyrite present in the coal mines can pose quite a serious problem of water
    pollution and land pollution. This might, in turn, affect the fauna and flora of the region near the mining area.
  5. Deeper excavation of the ground for mineral extraction causes lowering of water table and results in the drying up of wells.

JADUGODA URANIUM MINES

                Jadugoda is a place, in the Singhbhum district of Jharkhand state. In this area, Uranium is extracted from three underground mines of depth ranging from 1600 to 2000 ft. The mining activities in this area have caused the following effects.

  1. In and around the mining area people are facing diseases like respiratory ailments.
  2. The incidents of Tuberculosis among the miners is very high
  3. Increases in miscarriage, impotency, congenital deformities, skin disease, cancer, megacephalic, microcephalic and nervous disorders have also been extensively reported in this area.

ENVIRONMENTAL MANAGEMENTS IN MINING PROCESS TO CONSERVE NATURE AND MINERAL RESOURCES

  1. The formation of mineral deposits requires millions of years which cannot occur within the human scale of time. Once the deposit is used it becomes exhausted. Therefore, over consumption of the mineral resources should be avoided.
  2. Reuse and recycle of the minerals/metals is another option to conserve the mineral resources.
  3. Restoration of the land damaged by mining process should be made essential to conserve the flora and fauna of that region.
  4. Systematic and appropriate disposal of debris without spoiling the earth, water or vegetation should be followed.
  5. Afforestation should be followed.

BIOMINING

                Biomining is the process of extracting valuable metals from ores and mine tailings with the assistance of microorganisms.  It is a very low capital, low operational cost, and a little energy input process. This technology is also environmentally friendly as it generates a minimal amount of pollutants.

Bioleaching

The process of solubilization of metals from ores is called leaching. As micro-organisms are employed to solubilize metals, it is called bioleaching. It is employed for the recovery of metals such as Copper, Zinc, Lead, Arsenic, Uranium, Cobalt, Gold, Nickel and Molybdenum from ores. The microbes that leach metals from ores are called bleachers. The microbes Leach put metals in ores, in the form of metal salts. The leaching may be either direct or indirect.

  1. Direct Bioleaching: In this method, the microbial culture is directly applied to the ores. These microbes secrete certain enzymes, which oxidize the metal ions and release metal sulfides from the ore.
  2. Indirect Bioleaching: In this method, microbes oxidize ferrous ion and sulfide into ferric sulfate to generate energy. Ferric sulfate is a strong oxidizing agent that dissolves many metal sulfides. This metal sulfide is oxidized to metals and elemental sulfur.

Micro-organisms involved in Bioleaching
Name of the microbe Minerals extracted from the ores
Thiobacillus ferrooxidans Copper, Uranium, Cobalt, Nickel, Zinc, Lead
Thiobacillus acidophilus Ferrous & Copper
Thiobacillus organoparpus Ferrous & Copper
Thiobacillus thiooxidans Zinc & Lead
Leptospirillum ferrooxidans Ferrous & Copper
Sulfolobus acidocalcarius Ferrous, Copper & Molybdenum

Pros and Cons of Biomining

I.  Requires very less amount of energy input.

II.  Economical.

III.  Well suited for low-grade ores and tailing.

IV.  It does not pollute the environment and thus eco-friendly.

V.  It is a very slow process that takes a year for completion. Hence, it becomes difficult to extract enough metals in time to meet the demand.

 

 

 

 

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