Mining is defined as the extraction and processing of mineral resources into finished products.
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Mining of Gold
Mining of gold refers to the process of extracting gold from the earth’s crust. Gold mining has been practiced for thousands of years and remains a significant economic activity in various parts of the world.
The process of gold mining typically involves the following steps:
1. Exploration: Before mining can begin, exploration activities are conducted to identify potential gold deposits. Geologists and exploration companies use various techniques, such as geological mapping, geochemical analysis, and geophysical surveys, to locate areas with high gold potential.
2. Site Development: Once a viable gold deposit is identified, the site is prepared for mining operations. This involves clearing vegetation, constructing access roads, and establishing infrastructure, such as camps, offices, and processing facilities.
3. Extraction: The extraction of gold from the earth can be achieved through different methods, depending on the characteristics of the deposit. The two main methods are:
– Open-pit Mining: This method is used when gold deposits are near the surface. Large-scale equipment, such as excavators and haul trucks, is used to remove the overlying rock and soil to expose the gold-bearing ore. The ore is then extracted and transported to a processing plant for further treatment.
– Underground Mining: This method is employed when gold deposits are located deep underground. Underground tunnels and shafts are created to access the gold-bearing ore. Miners extract the ore using specialized equipment and transport it to the surface for processing.
4. Processing: Once the ore is extracted, it undergoes processing to extract the gold. The process typically involves crushing the ore into smaller particles, followed by various techniques such as gravity separation, flotation, or cyanide leaching to separate and extract the gold from the other minerals in the ore.
5. Refining: After the gold is extracted from the ore, it may undergo further refining to remove impurities and achieve a higher level of purity. Refining methods can include smelting, electrorefining, or chemical processes to produce refined gold bars or other forms suitable for commercial use.
6. Environmental Management: Gold mining operations must adhere to environmental regulations and practices to minimize the impact on ecosystems and communities. This includes measures such as proper waste disposal, reclamation of mined areas, and responsible water usage.
Gold mining can have both positive and negative impacts. On one hand, it contributes to economic development, employment, and revenue generation. On the other hand, it can lead to environmental degradation, social conflicts, and health hazards if not managed responsibly.
It’s worth noting that the specific processes and techniques used in gold mining can vary depending on the location, scale of operations, and technological advancements. Additionally, gold mining practices are subject to local laws, regulations, and environmental considerations.
South Africa is the largest producer of gold in Africa, followed by Ghana, Zimbabwe and Zaire.
Major mining areas include:
- Witwatersrand near Johannesburg (South Africa)
- Werksdorp and Welcom in South Africa
- Dunkua and Tarkwa in Ghana
- Gatoama and Gwanda in Zimbabwe.
Methods of Mining Gold
Gold is mined by the underground or shaft method. Here, vertical shafts are driven through a hole to reach the ore bearing rocks. Explosives are then used to fill the holes to shatter the rocks by blasting. The broken rocks are taken to the surface then to the concentrator that filters out the Gold which is later sent to the smelters for further refining and processing.
Transportation and Marketing
In South Africa, Gold is mainly transported by rail and road to processing factory or to Port Elizabeth or East London for export. Major market for Gold include the USA, Canada, Britain, Japan, Australia etc.
Petroleum or crude oil is an important fuel mineral produced in Nigeria, Libya Algeria, Egypt and Gabon.
- Port-Harcourt and Warri in Nigeria.
- Mersa and Bregha in Libya.
- Rahala Field near Ourgla in Algeria etc.
Method of Mining Petroleum
Petroleum is mined by drilling method (but refined and separated in different components by Fractional distillation method). In the drilling method, the underground rocks are sampled and tested for traces of oil. When the oil is discovered, a well is sunk to reach it with the aid of a drilling rig or derrick. The oil is then pumped out mechanically or naturally if the pressure within the oil zone is very high.
In the soil, three (3) layers within the oil zone exist (i) Natural gas is found on top (ii) Petroleum or crude oil in the middle and (iii) water at the bottom.
Transportation and Marketing
Crude oil is transported mainly by Pipe lines either to the refineries for refining or to the ports for export. Major markets include Britain, Japan, Germany, South Africa, U.S.A etc.
Copper is also a metallic mineral produced by Zambia, Zaire, South Africa and Zimbabwe.
Major Mining Areas
(i) Ndola, Nchanga and Chibuluma in Zambia
(ii) Shaba province in Zaire especially around Lumumbashi and Kolwezi districts
(iii) Messing in South Africa
(iv) Uwkundu and Nankia in Zimbabwe.
Methods of Mining Copper
Depending on the depth of the mineral in the soil, two methods are used to mine copper.
(a) Open cast method (b) Underground or shaft method
Open Cast Method
In this method, explosives are used to remove the over burden rocks and a machine called dragline is used to pile the copper washed into a heap. A monitor is used to direct a strong jet of water towards the heap.
The water washes the soil through a series of sluice boxes. In the process, the copper ore settles at the bottom of the sluice boxes while the water carries the dirt away. Finally, the copper concentrate is sent to the factory for smelting.
Transportation and Marketing
Copper is transported by rail to the port of Beira in Mozambique through Zimbabwe because Zambia is a land locked country. Roads are sometimes used to transport copper to the port of Dar-es-salaam in Tunisia for export. Major market for copper includes European countries, Japan and the USA.
ECONOMIC IMPORTANCE OF MINERALS
- The mining of minerals provide jobs for many people.
- They generate revenue to the government through the payment of company taxes, import and export duties.
- They also serve as foreign exchange to the government.
- They provide essential goods or products such as necklace, medals, kerosene, fuel etc to the people.
- Some mineral materials are essential for manufacturing industries, hence leads to growth of several industries.
- Minerals in an area can raise the standard of living of people in such areas e.g. the availability of crude oil in Port-Harcourt.
- Provision of social and basic amenities which in turns lead to the overall development of the area.
- Through the availability of mineral resources in an area, new skills are acquired by the people.
- They lead to growth of towns such as Johannesburg, capetown, Port-Harcourt, Warri, Takwa etc.
- They also lead to increase in socio economic activities.
PROBLEMS OF MINING
- Inadequate capital to exploit the minerals.
- Poor transport network.
- Poor technological know-how. This makes Africa to remain poor inspite of the vast mineral resources in the land.
- Out-dated topographical and geological maps.
- Difficult terrain increases operational cost.
- Fluctuations in world prices of minerals.
- There is problem of constant conflicts with the local people and the prospecting companies.
- High level of environmental pollution.
- Poor management due to government insensitivity and negligence.
- High rate of sabotage by unpatriotic people in the mining areas.
- Political instability in Africa.
GENERAL EVALUATION QUESTIONS
- Mention two areas in Africa where copper is mined.
- Give four economic importance of minerals to the people of Africa.
- State the areas of mining crude oil in Nigeria.
- Which country is the largest producer of gold in Africa?
- Explain the method of mining copper.
Discuss any one of Gold, Copper or Petroleum under the following headings: (a) Areas of mining (ii) Method of mining (iii) Transportation and Marketing