You imagine the open-air coal mine look like? Black is a large open pit and bustle of large machinery it? Small dragon today to take you to the Inner Mongolia Jungar million mu of farmland to see, where rich green , potatoes, corn, cereals, soybeans, rapeseed... Here, you can start an industrial tour and play a farmhouse!
Did you know that this place was once an open-air stop in your impression? After the development of coal resources, Shenhua Zhuneng Group turned the open-pit mine into a million-acre farmland.
Do not believe? Please see the “Four Quartet†of Shenhua Zhuneng Group! After the coal mining, the Zhuneng Group will reclaim the land, including landform remodeling, soil rebuilding, vegetation reconstruction, and landscape reconstruction. Tell you a small detail, in the process of peeling off the surface soil and rock, because the surface humus soil takes many years to form, so they will collect this thin layer of humus as a treasure, after backfilling Put it back again!
Having said that, are you interested in how open pit mines are mined? Xiao Shenlong will do a micro-science for you:
Micro science time
As the name suggests, open pit mines are of course open-pit mining. However, how does the open pit mine form the stope? How to transport the coal? How to protect the environment after mining? With these problems, let us go into the Shenhua Zhuneng Group Heiqigou Open-pit Coal Mine to find out:
The Heipougou Open-pit Coal Mine is located in Zhungeer Banner, Ordos City, Inner Mongolia. It is one of the three major projects of the first phase of the Zhungeer Project, a key project during the National Eighth Five-Year Plan period. It is an extra large design and self-construction in China. Open pit mine.
How to open-pit mining?
To extract coal from open pit mines, it is necessary to remove the rock and coverings overlying the coal seams so that the coal is exposed to the surface for mining. The process of removing the earth rock is called stripping, and the process of producing coal is called coal mining. Open-pit coal mining usually divides the well field into several horizontal layers, which are mined from top to bottom and form a stepped shape in space.
What are the conditions for open pit mining?
Mining open-pit mines is not just about excavation. First, you must have a clear understanding of the geological conditions of the coal seams.
In general, in addition to the continuous stability of the coal seam, there is an important condition that the stripping ratio is appropriate. The stripping ratio is a proprietary name for open pit mining. One of the important features of open pit mining compared to underground mining is the large amount of stripping. In order to produce ore, it is necessary to strip a certain amount of rock, and the ratio of the amount of rock to be stripped to the amount of ore produced, that is, the amount of soil to be stripped per ton of ore is the stripping ratio.
Economically reasonable stripping is an important parameter in open pit mining design, mining planning and guiding daily mining and stripping production.
Comprehensive mining technology of open pit mine
After the open pit mine has the mining conditions, the next step is to determine the production process system. In the process of mining, a complete and advanced process technology is particularly important. According to the working characteristics of the equipment used in each process, it is generally divided into intermittent, continuous and semi-continuous operation processes. China's open pit mines basically adopt integrated mining technology. .
Such as: Heiqigou open pit mine
Upper loess layer
The upper loess layer has an average thickness of 49 meters and is continuously processed by a bucket excavator-tape conveyor-discharger. However, due to the thinning of the loess layer in recent years, the distribution is not continuous, and the wheel bucket process has been discontinued since 2013.
Central rock
The average thickness of the central rock is 56 meters, and the upper layer adopts the process of disconnecting between the single bucket excavator and the dump truck.
The lower layer uses throwing blasting—the shovel dumping process.
Lower coal seam
The average thickness of the lower coal seam is 28.8 meters, which is a semi-continuous mining process using a single bucket excavator - dump truck - pit side semi-mobile crushing station - belt conveyor.
What are the specific process links?
Part I: Ore Preparation
Mineral rock preparation includes perforation and blasting.
Perforation blasting is to drill a blast hole of a certain diameter and depth in the open pit rock, then put the explosive into it, and blast it with explosives to break and loosen the rock.
The piercing equipment of the Heilongjiang Open-pit Coal Mine is mainly a roller rig.
DM-H2 roller rig
Ammonium explosives, heavy ammonium explosives and emulsion explosives
Part II: Appliqué
The loading is the core of the open pit mine. The excavation equipment is used to take the ore from the whole or the explosion and load it into the transportation equipment or directly to the designated place.
Whether the selection of mining equipment is reasonable, directly affects the effectiveness of the entire open-air system, the reliability of production activities and economic effects, the Heipougou open-pit coal mine generally uses a single bucket excavator.
Part III: Transportation
The mined coal is sent to the crushing station, storage area, etc.; the stripped rock is sent to the dumping site; the personnel, equipment and materials needed in the production process are sent to the working place. The above constitutes an open pit coal transportation system. Transportation methods include intermittent transportation, continuous transportation, and combined transportation.
Part IV: Dumping
The dumping is what is said above, and the large amount of topsoil and rocks that have been stripped off are transported to a specially set site such as a dumping site for disposal.
The last step: reclamation
Shenhua Zhuneng Group has been committed to the construction of green mines, focusing on development and protection, strengthening ecological construction, improving the ecological environment of mines, and achieving organic integration of resource, ecological, economic and social benefits. The mining area after mining has become a good field.
The "staircase" of open pit mines
Many people ask: How is the “step†of the layer in the Heiwagou Open-pit Coal Mine formed?
In the original open-pit coal mining, the coal seams in the stope are usually divided into several horizontal stratifications with a certain height, which are mined from top to bottom and maintained a certain advanced relationship. The layering of the mining presents a stepped shape, which is the one we usually see. The step is one of the basic components of an open pit mine and is a unit for independent stripping of rock and mining operations.
The general procedure is:
First of all, in order to mine a step and transport the mined ore out of the stope, a transport channel with a certain slope is built from the upper part—into the ditch, and a certain length of open ditch is built perpendicular to the direction of the mine.
Then expand the width of the opening trench, which is called the expansion. When this step has a sufficient width, a new step is developed horizontally downward.
Advancing layer by layer, the "staircase" of open pit mines is formed.
The beauty of the mine
Open pit mining has many advantages. About two-thirds of the world's total solid minerals use open-pit mining.
First of all, labor efficiency is high, production cost is low, construction speed is fast, resource recovery rate can reach over 90%, and resource utilization is reasonable;
Secondly, the labor conditions are good, the safety is guaranteed, the open-air operation does not have to worry about gas and water, and the accident mortality rate is lower than that of underground coal mining.
The design and mining scope of Shenhua Zhuneng Group Heiyugou Open-pit Coal Mine is 42.36 square kilometers, and the recoverable raw coal reserves are 1.498 billion tons, and the approved production capacity is 34 million tons.
Today, the main large-scale machinery and equipment used in the mining of the Heiqiou Open-pit Coal Mine is the most advanced mining equipment imported from the United States, Germany, Japan, the United Kingdom and Canada.
The scale of the mine is large, the resources are abundant, and the technology is high. It is one of the large open-pit mines in China!
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