Mining is the responsible practice for extract minerals from nature for commercial use. consists of the research, exploration, mining (extraction) and mineral processing present underground. The rocky portion of planet Earth is composed of rocks, which, in turn, are composed of minerals.
Some of these minerals and rocks are considered valuable because they have some kind of economic utility that makes them have a higher market value, they are called ores. Some examples of ores are: iron, copper, gold, granite, marble and many others.
This is an activity of the economic sector indispensable to the socioeconomic development, as most products and resources used by the population come from this activity. This means to say that it is responsible for the generation and distribution of raw material, which are resources used in manufacturing and production in goods, usually industrialized.
In addition, mining is also classified as a practice of extractivism, since it is characterized by the removal of a natural resource from its environment.
→ Where are the ores found?
Most of the ores, in their solid form, are found in geological regions called crystal shields (also known as cratons and old massifs).
These locations have magmatic and metamorphic rocks (such as basalt, granite and marble), and along with them there is a large amount of precious minerals. In the sedimentary basins — another type of geological formation — the mining activity finds the Petroleum, O natural gas, O mineral coal it's the limestone.
The formation of mineral deposits in nature is very long and can take millions of years to happen, but it can be depleted in a short period of time, depending on the location.
→ Types of mining
The types of mining are known as mining methods, which refer to techniques applied in ore extraction. These methods take into account the characteristics of the area where the activity will be carried out, such as form, ore depth and geological aspects. At this point, aspects are also considered. economic, social and environmental, as well as questions from safety and hygiene, in order to maintain the life of the mine.
The two main methods are:
Open-pit mining consists of exploring ore found in shallower deposits.
open pit |
It is the method of extracting ore found in deposits close to the surface. There is, normally, exploration of the ore until the mine is exhausted. The main examples of this method are: - Slopes; - Caves; - Slices; - Mining by dissolution. |
Underground mining consists of the exploration of ore found in deeper deposits.
underground mine |
It is the method of extracting ore found in deposits far from the surface. Surveying services help with this type of method. The main examples of this method are: - Self-supporting highlights; - Embedded highlights; - Rebate. |
→ Mining in Brazil
Brazil is one of the main countries in terms of mining, as it has a very large territorial area. It is considered a country with enormous potential in the mining sector and, according to the National Department of Mineral Production, produces around 70 mineral substances. There is gold in various parts of the region amazonian; iron, copper and aluminum, at the For is on Minas Gerais; Petroleum, in the regions Southeast and North East; and mineral coal, in the region South.
Read too:The pioneers and mining in Brazil
According to the Brazilian Mining Institute, Brazil has more than eight thousand companies mining companies, which are distributed among the regions, and more than three thousand mines. THE Southeast region is where these companies are most concentrated, followed by South region. The region with the lowest number of companies is the North region.
Mining Industries in Brazil
The country also has two of the largest companies in the world in the mining area: the Petrobras and the Vale do Rio Doce, the latter is considered to second largest mining company in the world. Vale (as it is currently called) was once a state-owned company, that is, it belonged to the government, but it was privatized in 1997. Petrobras, on the other hand, despite having part of its shares sold, continues to belong to the state.
There are also other large companies in the country:
- Samarco
- CBMM
- Alumor
- Namisa
- Magnesite
- Votorantim
- Hispanobras
Main ores found in Brazil, according to research carried out by the Brazilian Academy of Sciences:
Asbestos |
Coal |
Copper |
Bauxite |
Iron |
Niobium |
Gold |
Tin |
Nickel |
→ gold mining
Gold mining, when done improperly, can cause numerous environmental problems, such as soil contamination.
The exploration of gold dates back to the times of Brazil Colony. Gold was found in the states of Minas Gerais, Goiás and Mato Grosso, and recent discoveries claim that there was also gold in São Paulo.|1|
In the past, miners who went in search of gold looked for it, counting on luck, among the river beds and rocks. As technology advanced, new gold exploration and extraction techniques made mining more accurate.
Ore exploration varies according to the geological characteristics of the deposit. If the deposit is found near the surface, the method of open pit. If you find yourself more away from the surface, the method applied will be underground mine.
Briefly, gold mining happens as follows: topographic studies are carried out in the area, in order to analyze the ore samples before starting the drilling. The second step refers to the extraction of ore, followed by the third step, known as processing.
This last step represents the preparation of the ore through the crushing (process in which the ore is reduced into smaller pieces.); of sieving (process in which the large and small pieces are separated); gives milling (process in which the ore is mixed into fine powder. The mixture will result in a finer ore for the hours that the mixture lasts); and of the classification (process in which coarse particles are separated from fine particles).
Once the processing stage is completed, the concentration phase, which could be gravitational or through the flotation.
→ Environmental impacts caused by mining
Tragedy in Brumadinho confirmed 180 dead and more than 100 missing people. (Credits: Fire Department of Minas Gerais.)
Mining, despite being considered a very important economic activity, has some problems. Most of them are in the environmental field, since the mining activity can assault the ground, to tease erosions and, when carried out in forest regions, expand the logging.
Also, there are social problems caused: by unemployment generated by depletion of deposits minerals; fur abandonment of these by mining companies, generating problems of conservation of geographic space; and for noise pollution caused by the mine explosions.
Brazil has supervisory bodies, concession and enforcement of laws, such as the Ministry of the Environment, the Ministry of Mines and Energy, the Geological Survey of Brazil and the Brazilian Institute for the Environment Renewable Natural Resources (Ibama).
When companies do not comply with the rules established by law, these bodies act in a coercive manner. Therefore, it is the responsibility of mining companies to stick to safety issues considering any possible impact social or environmental.
One of the most recent problems related to mining activity in Brazil caused an enormous social and environmental impact. two big environmental crimes occurred in the state of Minas Gerais involving the company Vale, whose dams broke, firstly, in the city of Mariana, in 2015, and, later, in the city of little mist, in 2019.
Read more: Disruption of the dam in Mariana
The failure of these dams, which contained tailings from the mining activity in the area, caused deaths; loss of biodiversity; Contamination of ground and of the water resources; cities were destroyed; people meet missing; and there are still controversies about the company's responsibility for this huge disaster.
Summary
Mining is the economic and industrial activity that comprises the stages of research, exploration, extraction and processing of minerals.
Mining is of paramount importance for the socioeconomic development of a society.
The ores are found in geological regions called crystalline shields.
There are different mining methods. The best known are open-pit and underground mining.
Brazil is one of the richest countries in mineral resources and produces around 70 substances.
The Southeast Region is the region of the country with the highest concentration of mining companies.
Mining is associated with several negative environmental impacts, such as aggression to the soil, deforestation, visual, noise and air pollution.
