Classification of mines

Size:

Mines include coal mines, metallic mines, non-metallic mines, building materials mines and chemical mines. Mine size (also called production capacity) is usually expressed in terms of annual or daily production. Annual production is the amount of ore produced by the mine each year. According to the size of the output, it is divided into three types: large, medium and small. The size of the mine scale should be commensurate with the economic and reasonable service life of the mine, only in this way can we save capital construction costs and reduce costs. In the process of mining production, mining operation not only consumes the most manpower and material resources, occupies the most funds, but also has the greatest potential to reduce mining costs. The main way to reduce mining cost is to improve labor productivity and product quality and reduce material consumption.

Digital Mine:

Canada has developed a vision plan to be realized by 2050: a mine in the remote northern region of Canada will be realized as an unmanned mine, from Sudbury through satellite control of all equipment in the mine to achieve mechanical automatic crushing and automatic cutting mining; The Finnish mining industry also announced its own intelligent mining technology program in 1992, involving 28 topics such as real-time mining process control, real-time resource management, mine information network construction, new machinery application and automatic control; Sweden has also developed a strategic plan "Grountecknik 2000" to advance towards mine automation. China University of Mining and Technology has also carried out technical development and application research on mining robot (MR), mining Geographic information system (MGIS) [1, 2], three-dimensional geoscience simulation (3DGM) [3], mining virtual reality (MVR) [3], mining GPS positioning and other aspects.

In July 1997, the Australian Commonwealth Science and Industry Organisation (CSIRO) developed a three-year research plan on coal exploration and mining, with an investment of $31 million, focusing on 18 specific projects in six areas: resource assessment, mining process innovation, mine gas control and utilization, automation, safety and material fine control. Among them, geological assessment and emergency response are the two most distinctive items. 1) Geological assessment: a 3D block model-based software was developed to assess the stratigraphic environment (sedimentary environment) of a mine or mining area; An interactive 3D (and 4D) software package for 3D visualization of heterogeneous data (microseismic monitoring data, neutron gamma sampling data, etc.); The rock mass deformation after mining is simulated by finite element/finite difference (FE/FD) model. 2) First aid response: Developed a personal safety positioning and monitoring system, which is composed of control devices, monitoring equipment, network lights and miners' different frequency radar transceiver unit, with wireless communication capability, and can report the location and safety status of underground miners even after underground disasters such as gas explosions; And developed a remote control unmanned ambulance called Numbat, used for emergency rescue of the wounded after the explosion.

With the application of real-time mine survey, GPS real-time navigation and remote control, GIS management and auxiliary decision making and 3DGM, some large open pit mines in the world (including Pingshuo and Huolinhe mining area in China) have been able to generate deposit models and mining plans in the office, and connect with stope equipment to form a dynamic management and remote control command system. In addition, Artificial intelligence technologies such as expert system, neural network, fuzzy logic, adaptive pattern recognition, genetic algorithm, GPS technology, parallel computing technology, radio frequency identification technology, global optimization method for rock mechanics problems and remote sensing technology have been applied in intelligent mine geological exploration and survey, intelligent mine design, intelligent mine mining, planning and control, and remote sensing of mine disasters The research field of paper has been applied.

Mine rescue

In the process of mine construction and production, due to complex natural conditions, poor working environment, coupled with people's understanding of the objective laws of mine disasters is not comprehensive and in-depth, sometimes paralyzed carelessness and illegal operations, illegal command, which causes the possibility of some disasters. In order to deal with mine accidents quickly and effectively, protect the life safety of workers, and reduce the loss of national resources and property, it is necessary to do a good job of rescue work in accordance with the requirements of the two "regulations" (coal mine safety regulations, coal mine rescue regulations). At the same time, it is necessary to educate employees how to actively carry out self-rescue and mutual rescue in the event of an accident.

Mine rescue team is a professional team dealing with mine fire, gas, coal dust, water, roof and other disasters, is a professional, technical organization, strict implementation of military management. Practice has proved that mine rescue teams play an important role in preventing and dealing with mine disasters and accidents.

Mining method:

According to the different stope management methods in the ore recovery process, the mining methods of non-coal mining mines can be divided into four categories:

(1) Open stope mining method is characterized by the fact that in the mining process, the goaf mainly relies on temporary or permanent residual pillars to support, and the goaf is always empty, which is generally used when the ore and surrounding rock are stable.

(2) The caving mining method is characterized by the planned use of the overlying rock layer of the caving ore body and the rocks of the upper and lower wall to fill the goaf with the ore extraction to control the ground pressure in the mining area. Generally, it is used under the condition that the surrounding rock of the ore body is unstable and the surface allows subsidence.

(3) The filling mining method is characterized by the support of the goaf by the filling material within the goaf during mining. This method can effectively maintain the gob, the stability of the surrounding rock is not high, but the production cost is high. It is mainly used for mining high ore value, sufficient filling materials, the surface does not allow subsidence and the geological conditions are particularly complex.

China is a large country of stone resources, the total reserves of stone resources in the forefront of the world, the national annual production of more than 7 million cubic meters of raw materials, the total stone mining also ranks in the forefront of the world, but the overall level of China's stone mines is still backward, the utilization level of stone resources, mining raw materials rate and ore recovery rate are not optimistic.

Mine design:

Mine design is not only a stage in mineral resources development, but also an important link in mine construction. It refers to the comprehensive planning work for the construction and production of mines on the basis of the results of geological exploration. The aim is to select a technically feasible and economically reasonable mineral resource development scheme according to the occurrence and economic and technical conditions of the deposit.

The main contents are: to determine the mine production scale, service life, process flow, product program, etc., and to choose a reasonable plan for the deposit development program, mining method, ore washing and processing technology, main mining equipment, surface and underground engineering layout, power supply, water supply and drainage and construction organization; Accounting construction investment, preparation of individual project design and construction drawings, etc.

Hidden danger control:

dust

The comprehensive dust suppression technology mainly includes biological nano film dust suppression technology, cloud dust suppression technology and wet dust collection technology.

Biofilm dust suppression technology, biofilm is a double ionospheric membrane with nanoscale layer spacing, which can maximize the ductility of water molecules and has strong charge absorption. The biofilm sprayed on the surface of the material can attract and agglomerate small particles of dust, and make them polymerize into large particles of dust, which will settle with the increase of its own weight; The dust removal rate of the technology can reach more than 99%, and the average operating cost is 0.05~0.5 yuan/ton.

Cloud dust suppression technology is through high pressure ion atomization and ultrasonic atomization, can produce 1μm~100μm ultra-fine dry fog; The ultra-fine dry fog particles are fine, and the contact area with the dust particles is fully increased. The water fog particles collide and condense with the dust particles to form agglomerates. The agglomerates continue to grow larger and heavier until they settle naturally at the last moment, so as to achieve the purpose of eliminating dust. 30%~40% of the dry fog particles are below 2.5μm, and the control effect of fine particle pollution in the atmosphere is obvious.

The wet dust collection technology absorbs the air attached to dust by pressure drop, and dedusts under the double action of centrifugal force and the mixing of water and dust gas. Key designs such as unique impellers provide higher dust removal efficiency.

Suitable for bulk material production, processing, transportation, loading and unloading and other links, such as mines, buildings, quarries, storage yards, ports, thermal power plants, steel plants, garbage recycling and other places.

Security risks:

Mine high temperature and high humidity

The air temperature in the mine is characterized by high temperature, high humidity, large temperature difference, and different airflow sizes at different locations. The level of air temperature is related to the depth of the roadway, the underground temperature increases, and the underground working environment heat damage is serious. At the same time, it is difficult to supply fresh air source and deal with dirty air source in deep mining area. The adverse temperature conditions in mines are an important factor in the increase of upper respiratory tract infections and rheumatic diseases among workers. If these problems are not well solved, not only do these enterprises have the risk of casualties and occupational hazards, but also make normal production can not proceed smoothly.

Mine dust

Production dust is the main harmful factor of underground mine. Many production processes and processes, such as drilling, shooting, mining, rock loading, transportation, etc., can produce a large amount of dust. Workers for a long time to absorb this kind of dust, can occur silicon lung, coal lung or mixed pneumoconiosis. At present, 70% of the world's pneumoconiosis patients are in China, and the number of mine pneumoconiosis deaths in China exceeds the number of work-related deaths. The dust concentration in the mine is high, and the dust concentration qualification rate of the underground mine is only 40%-60%, and the open pit mine is only 70%-80%. With the decrease of mining depth, the comprehensive hazards such as air pollution in deep concave open pit should be paid attention to.

Toxic and harmful gases from mines

Methane is often present in mine air, and its main component is methane. There are also harmful gases such as carbon monoxide, nitrogen oxides and hydrogen sulfide. Methane is a colorless odorless flammable gas with a density of O.559kg/m3. Methane mainly comes from coal seam, coal block and rock wall. Methane can be mixed with air to form an explosive gas, which can explode in the event of an open flame. Methane explodes at concentrations ranging from 5% to 16%. An important source of carbon monoxide and nitrogen oxides is the smoke produced by blasting. The use of nitroglycerin explosives can produce a large amount of carbon monoxide, while the use of ammonium nitrate explosives often produce a large amount of nitrogen oxides. In a poorly ventilated mine, smoke poisoning may occur due to smoke accumulation after blasting.

Mine noise and vibration

Noise is one of the hazards that pollute the mine environment, and the underground operators suffer more from it. In recent years, the use of many large, efficient and high-power equipment has reduced labor intensity and improved production efficiency at the same time, resulting in more and more serious noise pollution. In particular, the underground equipment has the characteristics of multiple sound sources, continuous noise, high sound level and high and medium frequency noise spectrum. In addition, the underground working face is narrow and the reflecting surface is large to form a mixed sound field, and the noise can only propagate along the extension direction of the roadway, which is more harmful to the operators. Noise and vibration in mines are mainly generated during drilling, mining and transportation. In general, the noise and vibration of pneumatic tools are more serious than those of power tools and vibrating conveyors than belt conveyors. The labor intensity of miners is large, such as human tooling rock is heavy physical labor; Drilling and pushing are moderately manual labor. When working in thin layers, workers must not take bad positions such as squatting and stoop crawling throughout the working day.

Mine blasting safety

Blasting safety plays an important role in mine production. Blasting safety problems can be summarized into the following three categories: safety accidents caused by mechanical effects of blasting (such as seismic waves, shock waves, noise and individual flying rocks); Due to the physical and chemical reaction of explosive explosion, that is, a large number of toxic gases and electromagnetic effects caused by explosive explosion; Sudden accidents caused by blasting, such as early detonation of explosives, failure to detonate and safety accidents caused by operational errors. The accidents of personal injury and equipment damage caused by mine blasting occupy a large proportion in the whole mine accidents. With the development of mining industry, open pit blasting is very close to the industrial site of the mine itself, and there are also nearby towns and residential areas; Deep hole blasting and engineering blasting with large charge amount in underground mining are increasing day by day. The high temperature zone formed by mineral and rock material causes explosive self-detonation, early detonation, and smoke poisoning accidents often occur. The most typical is June 22, 2002, Shanxi Province Fanshi County Yixingzhai gold mine explosion accident, at least 37 miners were killed. Therefore, how to control the harmful effects of blasting and how to take protective measures is a problem that mines generally pay attention to. Safety accidents are no small things, especially the mining industry, only usually pay attention to this small aspects, in order to extinguish the accident in the bud!