Useful

fossils

Extraction of raw materials

Preparation and Enrichment

Product manufacturing

Rice. 1. General diagram of the production process in industry

Consequently, minerals constitute the primary, basic basis of industrial production. To obtain the final product, it is necessary to extract natural resources from the subsoil to the surface. This primary stage of industrial production is called prey. Mining is carried out using open and underground methods. In the first case, resources are removed from the subsurface after the rocks that cover them are removed. In this case, fossils are extracted as if from the surface of the earth. In underground mining, minerals are brought to the surface from under the overburden through special mine workings rocks. The choice of extraction method depends on the type of natural resources, mining and geological conditions of their occurrence and other circumstances. The most progressive method of extraction is open-pit mining. This is due to a number of advantages compared to underground mining. In open-pit mining, the working space is not limited, as in mines. As a result, favorable conditions for the use of powerful, high-performance machines. The production process is highly mechanized and is carried out almost without handmade. As a result, labor productivity is 3-6 times higher than in mines. A high level of mechanization reduces the labor intensity of production and provides easier, safer, more hygienic working conditions for miners. Due to the wide development of the scope of work, a shorter period is required for the construction of open-pit mines, and design capacities are mastered faster. As a result, capital investments during quarry construction are 1.5-2.5 times less than during mine development.

All the above circumstances explain the high efficiency of open-pit mining. Therefore, preferential development this method mining determines progressive trends in industry. The widespread development of open-pit mining is hampered by a number of circumstances. Firstly, developments are more dependent on natural conditions (climatic, mining and geological, etc.). It is enough to note that the extraction of minerals by this method, at the current level of development of scientific and technological progress, is limited to depths of up to 500 m. Secondly, there is a significant impact on the environment, which can be so negative that it makes the environmental factor the main one in determining the methods of extracting raw materials. However modern level the development of scientific and technological progress makes it possible to reduce the influence of these circumstances on the development of resources by open-pit mining.

1.2. Open development natural resources

All raw materials for the production of building materials, most of the iron, chrome, copper ores, a significant proportion of manganese, shale, coal and other minerals are mined using the open-pit method.

The use of open-pit mining is economically feasible provided that the cost per unit of extracted raw materials is less than or equal to the cost of its extraction underground. Open pit mining is used when resources are located relatively shallow from the earth's surface. Thus, in Krivoy Rog (Ukraine) iron ores are mined from depths of up to 250 m. The choice of method also depends on the thickness of the layers. Thin seams are not effectively developed even if they are relatively shallow, since it is necessary to move significant volumes of waste rock per unit of raw material. Therefore, only a part of all natural resource reserves is suitable for open-pit mining.

The production process of open-pit mining is much simpler than that of underground resource development. It consists of preparatory, stripping and cleaning works Preparatory work is carried out to remove natural and artificial barriers from the mining fields that hinder production. Typically, natural barriers are forests, rivers, swamps, lakes, etc. To carry out open-pit mining, forests are cut down, swamps are drained, and special wells or mine workings are created to lower the level groundwater. In order to protect developments from precipitation, ditches are laid through which water is drained outside the development. Artificial barriers can be various buildings (roads, settlements, etc.). If necessary, they are transferred beyond the boundaries of the deposits. During the preparatory period, access roads and various utilities are laid.

Fig. 2. CAREER DIAGRAM

When the above-mentioned work is completed at the deposit, stripping begins, that is, removing the waste rock covering the ore. The result is direct access to natural resources. Rock removal is carried out layer by layer (Fig. 2). During the development process, each layer takes the form of a ledge, a step. The end part is called slaughter Mining equipment and vehicles are placed on the ledge areas, and the ledge itself is called an overburden ledge. The method for removing overburden depends on its physical properties. Loose and soft rocks are removed mechanically using excavators and bulldozers. Hard rock is initially broken up by explosion and then moved by mechanical means. The excavated rock is transported to dumps– specially designated areas that can be located both in the mined-out space (internal dumps) and outside it (external dumps). Moving waste rock to dumps is called dumping.

Cleaning operations include operations to remove minerals from the subsoil, and they got their name from the essence of the purpose. They are carried out when natural resources are exposed. Extraction is carried out in the same way as when removing overburden - layer by layer. The ledges formed are called clearing ledges.

The main mechanical means when carrying out stripping and cleaning work is an excavator - a self-propelled earth-moving machine that excavates rock and moves it in a bucket. Excavators are single-bucket and multi-bucket.* Draglines are also used - rope-bucket excavators. They differ from single-bucket excavators in that the bucket and boom are connected by a cable. Draglines can be walking or crawler-mounted. In addition to excavators, scrapers, bulldozers, drilling and blasting equipment and other machines that have auxiliary purposes are used in open-pit mining.

Enterprises that represent a set of mine workings and equipment for open-pit mining are called quarries, and in the coal industry - cuts.

To assess the efficiency of open-pit mining, the indicator is used stripping ratio, which represents the ratio of the volume of waste rock to the amount of minerals extracted. This indicator shows the amount of waste rock moved per unit of raw material mined.

* Multi-bucket excavators can be chain (buckets are located on a chain) and rotary (buckets are located on a rotating wheel - rotor).

The stripping ratio when mining non-metallic materials is about 1 m³ of waste rock per ton of raw material (1 m³ /t), coal - up to 15 m³ /t. With the development of raw material extraction, more and more deposits with worse mining and geological conditions are being developed, and this causes an increase in the stripping ratio. So, in the 60s, at coal mines in Kuzbass this figure was 4 m³/t, and in the 90s – more than 7 m³/t. This indicator dynamics is favored by the use of increasingly powerful equipment, which makes it possible to extract ore from the subsoil at lower costs.

Open-pit mining has a significant impact on the environment. Firstly, this influence is due to the withdrawal from economic activity of significant land for quarries and dumps, which in modern conditions at each enterprise occupy an area of ​​​​several square kilometers. It is enough to note that the size of one of the largest coal mines, Bogatyr (Kazakhstan), is about 10 km². In the largest mining areas, tens of thousands of hectares are occupied by quarries and dumps. It can be noted that very productive soils are allocated for them. So, at the Kursk magnetic anomaly for development iron ores About 15 thousand hectares are allocated, including 9 thousand hectares of arable land, and here the most productive soils in the world are chernozems, which further increases the negative environmental impact on the environment.

The construction of quarries hundreds of meters deep causes a decrease in groundwater levels. And this negatively affects the water supply of the farm, as well as soil productivity.

Overburden dumps have a significant impact on the environment. In addition to the withdrawal of land from economic activity, dumps pollute the air, water, and soil with elements of dump rocks. The depth of this process depends both on the scale and chemical composition dumps. Thus, salts enter the components of nature, change their chemical composition, the vegetation of the environment, and increase the incidence of the population. The negative impact can be reduced by land reclamation and the use of all types of dumps for economic purposes. From dumps it is possible to obtain various building materials, mineral fertilizers, alumina, etc. At the same time, the cost of production is significantly less than from specially extracted raw materials.

1.3. Underground mining of minerals and fuels

Natural resources are developed using underground methods, the extraction of which is impossible or economically infeasible by open-pit mining. Typically, underground methods are used to extract minerals that occur at greater depths, with lower thickness of layers and other worse mining and geological conditions, when the cost per ton is equal to or less than open mining. The main types of underground mining are mining, underground leaching, underground gasification, oil and gas extraction.

The most widely used mine subsoil development Using this method, it is possible to extract raw materials from depths of up to 2 thousand meters. A mine is a set of mine workings through which minerals are extracted from the depths to the surface. Before development, the deposit is divided into mine fields - areas that are developed by one enterprise - the mine. Mine construction begins with the sinking of vertical shafts, which open the useful layer (Fig. 3.). Each shaft has at least two shafts, which improves its ventilation. The shafts carry the lifting and lowering of minerals, auxiliary materials, equipment, people, energy supply, ventilation, etc. For these purposes, the shaft is divided into sections for lifting and lowering working loads. A special compartment contains pipes for pumping out water, air, electrical and telephone lines. There is a compartment with ladders and platforms for independent lifting of workers from the mine in the event of a lifting mechanism failure.

Mines may have vertical mining openings that serve the same purposes as the shaft, but do not have direct access to the surface. These workings are called blind shafts.

1. Mine shaft.

2. Cross-cut.

3. Bremsberg.

6. Stretch of a coal seam.

7. Falling coal seam.

Rice. 3. LOCATION OF MINING WORKS IN THE MINE

In mountainous areas, horizontal or close to this position excavations are created to uncover fossils - adits. They perform the same functions as trunks. At the bottom of the trunk is created mine yard, where ore is loaded from vehicles into a lifting mechanism. Repair shops, electrical substations, depots, garages for transport, etc. are located here.

From the bottom of the shaft, horizontal capital mine workings are laid with the same functions. They can be carried out along the strike of the fossil layer and in waste rock. In the first case, such production is called drift, and in the second - cross-cut. The last working is laid from the shaft to the useful formation and is created to open it. The crosscut from the shaft is built in cases where the fossil lies in unfavorable conditions under natural or artificial barriers and it is not economically feasible to lay the shaft directly above the deposit.

Inclined mine workings are also created in the mine. If it is passed in the plane of the formation from overlying horizons, it is called Bremsberg, and from the lower ones - slope.

All of the above-mentioned mine workings are permanent structures, created during the preparatory period and operated for the same period as the mine. Capital excavations are reinforced with reinforced concrete and cast iron tubes and various equipment is placed in them. After laying capital workings, the industrial development of the deposit begins, which is achieved by carrying out cleaning work. Their essence comes down to separating the fossil from the formation and transporting the rock to the surface. The process of separating ore from a rock layer is called breaker, and the place where it is held is face or lava. Breaking is carried out by manual, explosive and machine methods. The choice of type of blasting depends on scientific and technological progress, physical and chemical properties of minerals. Back at the beginning of the twentieth century, the main equipment of miners was a butt, a drag sled that was pulled by workers. The ore was hauled away in trolleys driven by horses. In modern mines, hard rocks are blasted, less durable rocks (salt, coal) are separated by machine. In this case, special combines are widely used, which remove rock and load it onto a vehicle. Manual breaking using pneumatic hammers is used to a limited extent due to its high labor intensity and low labor productivity. As the rock is removed, the face and equipment move along the strike of the seam. This causes the instability of the workplace, and its gradual movement complicates the automation of work.

Separating the ore from the seam requires securing the overlying rocks from collapse. To do this, wood or metal support is used in the excavations, and the work is called fastening the roof.

The simplest method of removing ore from lava is to lower it under the influence of its own weight. This method is used when the face is located above the transport mine workings. Mostly ore is removed from lava using special cars, scraper mechanisms, conveyors and other vehicles. Through haulage mine workings, ore is transported to the shafts by belt conveyors and locomotives with trolleys with a carrying capacity of up to I tons, depending on the capacity of the mine. Battery and contact electric locomotives with a track width of 600-900 mm are used as locomotives. For comparison, we note that this indicator is railway transport is 1420 mm. Modern conveyors move up to 3000 tons of rock per hour.

The ore is lifted to the surface cage And skipovym ways. In the first case, the ore is lifted along the shaft together with a trolley, and after unloading on the surface, it is again lowered into the mine. A more efficient lifting - skip - in special containers with a lifting capacity of 10-50 tons, which are located in the shaft. At the same time, at the bottom of the shaft, the rock is reloaded from a vehicle into a skip, which rises to the surface. This lift is usually equipped with two skips. When one is under unloading, the second is loaded during this period, and then vice versa.

When mining subsoil, the surface of the earth is less disturbed compared to the open pit method. However, extracting ore from under the caprock creates voids in the depths. Under the influence of the plasticity of rocks, mechanical disruption of the subsoil occurs, surface subsidence occurs, swampiness of territories increases, artificial lakes are formed, cracks on the surface of the earth, and buildings are destroyed. With the expansion of the scale of development, these environmental phenomena are increasing significantly, which requires large capital investments for fastening

roofs. Improving methods for developing natural resources and filling mined-out voids with industrial waste can reduce the negative environmental impact.

In-situ leaching used for the development of uranium ores, salts, and non-ferrous metal ores. In Belarus, the Mozyr rock salt deposit is being developed in this way. Underground leaching is based on the properties of ores to dissolve in water and acids. With this method, the deposit is opened with wells equipped with a concentric arrangement of pipes according to the pipe-in-pipe scheme (Fig. 4). Through one of the pipes, a solvent is supplied into the subsurface. It is lighter than brine and is located at the top of the leaching chamber. The solvent is gradually saturated with ore components, becomes heavier, goes down the chamber and is squeezed out through one of the pipes to the surface. To stop ore leaching, inert substances (compressed air, petroleum products, etc.) are supplied into the chamber, which protect the top of the chamber from dissolution.

RICE. 4. DIAGRAM OF A DESCRIPTIVE WELL.

Thus, the process is much simpler compared to the mine one. Extraction of raw materials comes down to supplying solvent into the subsoil and transporting brines through pipelines to processing sites. This eliminates the presence of people underground, which improves working conditions, safety and increases productivity. The time it takes to prepare a field for exploitation is reduced, capital investments for the extraction of a unit of raw materials. According to the calculations of experts, it is only possible to drill and equip wells for mineral extraction only due to the costs of sinking mine shafts. Therefore, the cheapest raw materials are obtained in this way.

Underground leaching allows for a more rational use of subsoil resources and expands the raw material base of industry. Mining ore extraction is limited by the depth and conditions of rock occurrence. The development of deep-seated strata located in difficult mining and geological conditions using the mine method is not always advisable. Due to their plasticity, salt extraction is possible to depths of up to 1000 m. Economic use ores that do not meet the standard requirements can only be processed by underground leaching. This method expands the resource base due to a more complete removal of minerals from the subsoil of already mined sections of mine fields, where resource losses can reach 3/4 of the total reserves.

In-situ leaching is a more economical and environmentally friendly process. The use of special solvents makes it possible to extract only the useful component, and leave all other substances, which can make up more than 9/10 of the rock mass, in the subsoil. As a result, less waste is generated on the surface.

The economies of many countries depend on mining. This is one of the main resources for the development of industry, construction and the economy. There are two main mining options: underground mining and open-pit mining. The choice of method depends on the depth of valuable rock deposits, terrain features and other factors.

Extraction work useful resources from the depths of the Earth have a thousand-year history. Equipment and mining methods have gone through a serious evolutionary path. Nevertheless, the basic principles have been preserved.

Quarries are being developed in almost every corner of the planet. Metals, minerals, and construction raw materials are mined. This type of mining has a negative impact on the environment and environmental situation. However there is whole line advantages that determine the popularity of the open-pit mining method:

• simplified version of preparatory and construction work;
• high degree of safety for participants in the process;
• relatively low costs for organizing and conducting development;
• comfortable conditions for workers;
• the possibility of more efficient rock extraction.

The positive aspects of quarrying are identified in relation to other mining options (underground, combined). Labor costs for open-pit mining are quite high. The economic benefit decreases with the deepening of the pit. Delivery of the breed to the collection point is constantly becoming more complicated, increasing the cost of the procedure.

Open development technology

Extraction of natural resources is a process that consists of many stages. Preparatory work begins with geological exploration. Experts search for fossil deposits and estimate the likely volumes of mined rock.

Preparatory work

After positive results geological exploration stage begins primary training. Mining enterprises carry out the following work:

• uprooting of forests;
• drainage or watering of the area;
• construction necessary communications(sewage, communications, access roads);
• erection of administrative buildings and other premises.

The duration of the preparatory stage depends on the financial investment, the scale of the work, weather conditions, terrain features.

Minerals ( coal, metal, etc.) are hidden under waste rock. This layer of soil must be removed. To achieve this, stripping operations are carried out. The top soil is removed layer by layer. There is a systematic advance towards valuable deposits. As a result, a cascade of benches is formed, and the development of the quarry approaches the direct production phase.

The following equipment is used for stripping operations:

• bulldozer;
• excavator;
• dragline (excavator with rope connection);
• drilling and blasting equipment.

The efficiency of open pit mining is determined by the ratio of the displaced waste rock to the mining result. Quantity cubic meters the removed soil is divided by the tonnage of the removed mineral.

Mining process

After stripping operations, direct extraction of the mined rock is carried out. It is removed from the subsoil and transported to warehouses or processing plants. To reduce the cost of this stage of development, they use large-tonnage equipment and try to automate some processes.

Transportation of raw materials is often entrusted to mining dump trucks of the BelAZ plant. In 2013, a model was released that is capable of transporting cargo weighing up to 450 tons. During testing, the dump truck handled a record 503.5 tons.

New technologies and equipment that are used for development and production are regularly developed valuable species. The level of security is increasing, and some processes are being fully automated. But work in quarries and mines remains difficult and dangerous. Working conditions are often extreme and require high physical and psychological stability.

Quarry structure

Open mining is suitable for many valuable rocks. There are chalk quarries, coal quarries, amber quarries, marble quarries, and copper quarries. One of the largest open-pit mining sites is located in Utah, USA. Mining of the Bingham Canyon quarry began in 1863. The depth of the pit is about 1,200 meters. Active ore mining continues in the quarry.

Features of quarry development depend on many factors. We can identify the main elements that are characteristic of all such structures:

• working and non-working board;
• lower and upper contours;
• overburden and clearing benches;
• platforms (below the slope, above the slope);
• breed collection point;
• transport communications.

The bottom of the quarry is also often called the bottom - this is the lower platform of the ledge. Its dimensions take into account the necessary safety conditions for removing rock and loading at the last level.

The influence of quarries on the environmental situation

Each quarry development is a significant blow to environment and the ecological background of the area. Already at the preparatory stage of rock extraction, actions are carried out that destroy the landscape. Enterprises cut down entire forests, drain water bodies, and carry out blasting operations.

Open pit mining has a detrimental effect on the soil. Cubic meters of soil are removed for fossil deposits. Often these are lands that could be effectively used for agricultural purposes. The development of valuable rocks entails a decrease in groundwater levels. The region's water supply and soil productivity are declining.

Overburden dumps pose a particular danger. Scale negative impact depend on the depth of the quarry and the chemical composition of the soil. Dumps pollute water, air, and soil. Various salts can leach into vegetation and lead to increased risk of certain diseases in local populations.

Mining in quarries is always accompanied by:

• wastewater pollution;
• carbon monoxide emissions;
• loud noise.

All this also negatively affects the environment.

Ecological restoration measures

The open-pit method of mining is not distinguished by its gentle approach to the developed area, but Negative consequences can be leveled out somewhat. In many countries, companies involved in quarrying are required to carry out reclamation and replant the site with vegetation after the end of mining. This allows you to start the process of regeneration of the soil and the ecological background.

Working with industrial waste can also be optimized. From the dump rocks the following is extracted:

• mineral fertilizers;
• alumina;
• Construction Materials.

This makes it possible to expand the range of economic benefits for the mining industry and reduce the negative impact of dumps on the environment.

Conclusion

Open pit mining is common throughout the world. This method allows you to remove a wide variety of rocks: chalk, coal, etc. We have to come to terms with the fact that quarrying has a negative impact on the environment.

However, conscious states are trying to control this process by setting certain requirements for mining enterprises. Mining and development of valuable rocks is a help for a stable economy. It is difficult for governing bodies to refuse the impressive financial flow that lies in the bowels of the country.

Everything about everything. Volume 5 Likum Arkady

When did people start mining minerals?

Minerals are chemical substances or compounds that lie in the bowels of the earth in natural form. Ore is a deposit rich in some mineral for which it is mined. No one knows exactly when mining began. One of the first mining ventures recorded in history was the Egyptian expedition to the Sinai Peninsula around 2600 BC. e. They set out to mine mica, but discovered and mined more useful mineral- copper.

The ancient Greeks mined silver in mines south of Athens in 1400 BC. e. The Greeks built mines around 600–350 BC. e. Some of the wells reached 120 m depth. Later, other metals such as lead, zinc and iron were mined from these same spears. To supply their vast empire, the Romans mined minerals in large sizes. Their mines were everywhere - from Africa to Britain.

Among the most valuable Roman mines was the Rio Tinto mine in Spain, which produced a large number of gold, silver, copper, tin, lead and iron. Mining reached a large scale in the 18th century, when the Industrial Revolution began. Large quantities of coal were required for metallurgy and factory furnaces.

Therefore, coal mining developed rapidly. Modern mining technology was born in those times. In the 19th century, the so-called “gold rush” broke out in the United States. It started in California in 1848. Over the years, more than $500 million worth of gold was mined there.

In 1896, the gold rush swept through Alaska. IN South Africa in 1870, the largest deposits of diamonds were discovered, and in 1886, rich gold deposits were discovered.

Where did gold mining first begin? Gold is such a rare and precious metal that you might think it was only recently mined. Nothing like this! Gold is one of ancient metals known to man. We will never know when man first found it and

When did people start cutting their hair? Hair appears as a result of the development of the stratum corneum of the skin. It doesn't hurt us when we cut our hair because it doesn't contain nerve endings. Since hair is an important part of our appearance and it is very easy to cut and style it, people began

When did people start wearing wigs? Did you know that some discovered Egyptian mummies from over 4,000 years ago were adorned with wigs? Apparently, wigs were common for the Egyptians. IN Ancient Greece They were worn by both men and women. It is believed that wigs entered

When did people start using baths? Today we are proud of the level of cleanliness we have achieved. Almost every home has a bath or shower. But there was a time when in the United States you could find more radios in homes than bathtubs. And although we pride ourselves on our purity, we never