technical requirements for open-pit mining
The open-pit mining operation mainly included the processes of drilling, blasting, mining, loading, transportation, and dumping. According to the continuity of the work, it could be divided into intermittent, continuous, and semi-continuous. For different types of deposits, the mining technology requirements were different. Among the mining methods for flat deposits (the dip angle is generally less than 12°), the intermittent mining process is suitable for various geological ore and rock conditions; the continuous mining process has high labor efficiency and is easy to realize the automatic production process, but it can only be used for soft ore and rock; the semi-continuous mining process has the characteristics of the above two, but in hard rock, it needs to increase the link of mechanical crushing of rock. In the top-dump mining method, the characteristics of mechanical shovels and draglines should be considered to reasonably arrange the equipment combination. For example, when stripping high steps, due to the relatively light dragline shovel, the dragline shovel should be used more often. According to the needs, a mechanical shovel with a dragline shovel, two draglines with each other, or only one dragline shovel as a secondary top-dump plan could be used. The horizontal mining method had to consider the restrictions of the specifications of the stripping material transportation equipment (such as the dump bridge and the boom dump truck) on the spatial relationship between the stripping bench and the mining bench. In addition, different mining technologies had certain requirements for equipment, such as the drilling diameter of large-scale high-efficiency roller drills reaching 380 - 444mm; the charging vehicle that could mix cheap explosives and waterproof explosives on the spot; the mechanical shovel, the hydraulic shovel, and the front loading machine must have suitable bucket capacity; the electric locomotive, traction unit, self-tipping car, and dump truck must have suitable load capacity; and there must be corresponding bulldozers, shifters, graders, scrapers, and other supporting equipment. In the mining process, the optimization of relevant economic indicators such as production stripping ratio and bench height, as well as the balance and control of resource recovery rate, mining cost, mining efficiency, etc. needed to be considered. If you want to know more about the follow-up, click on the link and read it!
Open pit mining method
The open-pit mining method mainly included the technological processes of drilling, blasting, mining, transportation, and rock discharge. Piercing work was the primary process of open-pit mining. It was done by a down-the-hole drill or a roller drill to control the ore grade and improve the blasting quality. Explosions were used to blast rocks or rock formations to facilitate subsequent mining operations. Mining and transportation was the transportation of ore from the open space to a designated location. It was usually operated by excavators, cars, electric vehicles, and other equipment. Rock removal was to remove the rocks or rock layers produced during the mining process to maintain the unobstructed flow of the mining area. The open-pit mining method has the characteristics of large mining space, excellent working conditions, high labor productivity, and low mining costs.
Open pit mining process
The mining process of open-pit mines included drilling, blasting, shoveling and loading of ore (rock), transportation of ore and rock, and discharge of rock. Piercing was the primary process of open-pit mining. Its purpose was to provide holes for blasting to store explosives. The quality of the piercing was directly related to the efficiency of the subsequent blasting, mining, crushing, and other work. There were two methods of piercing: thermal piercing and mechanical piercing. Commonly used drilling equipment is divided into shallow hole drill (rock drill and rock drilling jumbo) and deep hole drill (roller drill and down-the-hole drill) according to the depth of drilling. Explosions were the key to the mining of open pits. The rocks were broken through explosions to facilitate the subsequent mining and transportation. The shoveling of ore (rock) was to load the blasted ore or rock into a transportation tool, such as a truck or a conveyor belt. The transportation of ores and rocks was to transport the shoveled ores or rocks to a designated location. The common transportation methods were trucks and tape conveyor. Rock discharge was to discharge the ore or rock from the transportation tool for subsequent treatment or processing. In general, the open-pit mining process was a continuous process, and each link played an important role.
What are the conditions for open-pit mining?
The conditions for open-pit mining included the following aspects: First, the coal seam must be continuous and stable to ensure that there would be no safety problems such as collapses during the mining process. Secondly, the stripping ratio needed to be appropriate, which was the ratio of the amount of soil and rock that needed to be stripped to the amount of ore mined per ton of ore. In addition, the comprehensive mining technology of the open-pit coal mine also needed to meet the mining conditions. In addition, mining open-pit coal mines also required a series of qualifications, including business license, mining license, safety production license, land certificate, and so on. At the same time, he also needed to apply for an environmental impact assessment report, approval documents from the environmental protection department, and a pollution discharge permit or pollution discharge registration form. Finally, the mining of open-pit coal mines also required the selection of appropriate mining methods according to the distribution of the deposit, such as continuous mining, intermittent-continuous mining, and intermittent mining.
Open pit mining methods and methods
The mining methods of open-pit mines included mechanized mining methods and non-mechanized mining methods. Mechanized mining methods mainly used mechanical equipment for mining, such as excavators, cars, electric vehicles, bulldozers, etc. The non-mechanized mining method used manpower or a combination of human and animal power to mine. According to the stope form of the stripping material, there were mainly pit mining methods and in-place mining methods. Pit mining methods included top-down mining, stone mining, spiral drilling mining, water jet mining, etc. In-place mining methods included in-place extraction mining. According to the location where the stripping was discarded, it could be divided into inner discharge mining method and outer discharge mining method. Internal drainage mining methods included toppling mining and digging mining. According to the mining technology, open-pit mines could be divided into mechanical mining and hydraulic mining. The hydraulic mining was only suitable for mining soft deposits, while mechanical mining was a widely used mining method in open pit mines.
Safety regulations for open-pit mining
The safety regulations for open-pit mining included many aspects: ** I. Safety Requirements for the Formation of Steps ** 1. ** Production bench height **: There is a clear regulation. If the height of the bench after the completion of mining exceeds the regulation, it needs to go through technical demonstration and be determined by the design on the premise of ensuring safety. 2. ** Explosive pile height during shoveling **: When shoveling with an excavator or a shovel, the explosive pile height should not be greater than 1.5 times of the maximum excavation height of the machine. 3. ** Regulations on non-working steps **: The final slope angle and minimum working platform width of non-working steps shall be specified in the design. Mining and transportation equipment, transportation routes, power supply and communication lines shall be set within the stable range of the working platform. The distance between the edge of the explosion pile and the central line of the standard gauge railway shall not be less than 2.5m, the distance between the edge of the explosion pile and the central line of the narrow gauge railway shall not be less than 2.0m, and the distance between the edge of the explosion pile and the edge of the car road shall not be less than 1m. ** II. Safety Requirements for Piercing Operation ** 1. ** When the drilling machine stabilizes the vehicle **: It should maintain a sufficient safe distance from the top line of the step slope. The minimum distance between the center of the jack of different types of drilling machines and the top line of the step slope is different (for example, the distance between the jack center of the trolley is 1m, the distance between the roller drill, the down-the-hole drill, and the wire rope impact drill is 2.5 m, and the distance between the soft rock mass and the rock mass is 3.5 m). There should be no cushion stone under the jack to ensure the stability of the step slope. No one should be on the platform when the drilling machine is working. Non-operating personnel should not stay around. The drilling machine and the electric shovel near the bottom line of the slope should not work at the same time. If the machine is shut down for a long time, cut off the power supply on the machine. 2. ** When drilling the first row of holes **: The angle between the central axis of the drilling machine and the top line of the step slope should not be less than 45°. 3. ** When the drilling machine is walking near the edge of the step **: Check whether the walking route is safe. The minimum distance between the protruding part of the outer side of the drilling machine and the top line of the step slope is stipulated for different types of drilling machines (for example, the minimum distance between the protruding part of the outer side of the trolley and the top line of the step slope is 2m, and the minimum distance between the protruding part of the outer side of the roller drill, DTH drill and wire rope impact drilling machine and the top line of the step slope is 3m). 4. ** When the drilling machine is moving **: There should be someone under the machine to guide and supervise it. It is not advisable to walk on the slope with a slope of more than 15°. If it is more than 15°, put down the drilling frame, assign someone to command and take anti-overturning measures. When walking, the driver should honk first. No one should be in front of or behind the track. No one should make a 90° sharp turn or walk on soft ground. When passing through high and low voltage lines, a sufficient safe distance should be maintained. No one should stay on the slope for a long time. No one should walk far away at night without sufficient lighting. Non-operators should not be in dangerous areas when lifting and landing the drilling frame. ** 3. Other aspects ** 1. ** Stripping ratio inspection **: The inspection content includes the mining ratio of the mine. By checking the design and production data and inspecting the mining situation on the spot, the inspection shall be carried out according to the Notice of the State Administration of Mine Safety Supervision on Carrying out the Special Rectification of Production Safety in Open Pit Mines, focusing on the serious imbalance of mining and stripping without taking any treatment measures. 2. ** Regarding underground to open pit mining **: When underground mining is converted to open pit mining, the goaf and karst caves must be explored, and the goaf and karst caves that pose a threat to the safety of open pit mining must be handled according to the design. When there are abandoned tunnels and goafs that threaten open pit mining, targeted safety precautions must be taken in advance. When open pit mining is carried out within the scope affected by underground mining, effective safety technical measures should be taken. 3. ** Safety platform and cleaning platform **: Safety platform and cleaning platform should be set up in the open-pit according to the design. 4. ** Working slope angle and step height **: The working slope angle shall not be greater than the designed working slope angle. The final side slope step height shall not exceed the designed height. The height of the production step shall comply with the relevant regulations. 5. ** Equipment, materials, and craftsmanship **: You cannot use equipment, materials, or craftsmanship that is prohibited by the country. 6. ** Mining sequence **: The top-down mining sequence should be divided into steps or layered mining. Small open-air quarries should adopt the step mining. If the step mining cannot be adopted, the top-down layered mining sequence should be adopted. The slicing height, maximum mining height and final slope angle of slicing mining in small open quarry shall be determined by design. The number of slices and the maximum mining height have different restrictions under different blasting operation methods. The width of the drilling platform for slicing mining shall be determined by design, and the minimum width of the drilling platform shall not be less than 4 meters. The minimum distance between adjacent quarries should be more than 300 meters. If you want to know more about the follow-up, click on the link and read it!
What are the mining processes of open-pit mines?
The open-pit mining process mainly included the following aspects: 1. ** Piercing work **: This was the primary process of open-pit mining. - ** Piercing Equipment **: - ** Down-the-hole drilling machine **: The drilling angle has a wide range of variation. It is highly mechanized, reduces the auxiliary operation time, has a high operation rate, is flexible, has light equipment weight, and has low investment costs. It can control the ore grade by drilling inclined holes, eliminate the root, reduce large pieces, and improve the blasting quality. It is suitable for drilling medium-hard ores and rocks. It is widely used in small and medium-sized mines at home and abroad. - ** Rotary drill **: A new type of modern drilling equipment developed on the basis of a rotating drill. It has high drilling efficiency, low operating costs, and a high degree of mechanized and automated. It is suitable for drilling operations of various hardness of ores and rocks. It is a widely used drilling equipment in open-pit mines around the world. - ** Rock drilling jumbo **: It was a new type of drilling equipment. One or more rock drills and automatic propellers were installed on a special drilling arm or bench. There was a walking mechanism to realize the mechanized operation of the rock drills. - ** Piercing cost **: In the entire open-pit mining process, the cost of piercing accounts for about 10% - 15% of the total production cost. 2. Explosive work: The purpose is to break the hard solid ore and provide suitable excavated materials for mining and loading. - ** Explosion Method **: - ** Shallow hole blasting **: The diameter of the blast hole is generally about 30 - 75mm, and the depth of the blast hole is generally less than 5m, sometimes up to 8m (the depth of the hole can be increased by drilling the drilling trolley). It is mainly used for the production of small-scale open-pit mines or quarries, cave rocks, tunnel excavation, secondary blasting, new open-pit mine package processing, the formation of hillside open-air single-wall ditch transportation channels, and other special blasting. - ** Deep-hole blasting **: a blasting method that uses drilling equipment to drill deeper holes as the charging space for mining explosives. Deep-hole blasting in open-pit mines is mainly based on the production blasting of steps. The drilling equipment mainly uses DTH drills and cone drills. It can drill vertical deep holes or inclined holes. The inclined holes are more evenly charged and the ore rock blasting quality is better. In order to reduce the earthquake effect and improve the blasting quality, measures such as large-area micro-delay blasting, interval charging in the hole or air interval charging at the bottom can be taken. - ** Chamber blasting **: A method of blasting by loading more or a large amount of explosives in the blasting chamber tunnel. Open pit mines are only used during the basic construction period and under specific conditions. Quarry mines are used when conditions are available and mining demand is high. - ** Multi-row-hole short-delay blasting method **: With the rapid increase in excavator bucket capacity and open-pit mine production capacity, open-pit mining is widely used at home and abroad, and the amount of blasting per time is large. - ** Multi-row-hole-delay squeezing blasting method **: refers to the multi-row-hole-delay blasting when there is a pile of debris left on the working face. The existence of the pile of debris creates conditions for squeezing, which can prolong the effective time of blasting, improve the utilization and crushing effect of explosives, control the width of the pile of debris, and prevent the ore and rock from scattering. The interval time of the micro-delay blasting is 30% - 50% longer than that of ordinary micro-delay blasting (50 - 100ms is commonly used in open-pit mines in China). Its advantages are better rock crushing effect and more concentrated explosion pile. Its disadvantages are higher explosive consumption, wider working platform requirements, and higher explosion pile height, which may affect the safety of excavator operation. - ** Explosion cost **: In the total cost of open-pit mining, the blasting cost accounts for about 15% - 20%. The quality of the blasting directly affects the efficiency of mining, transportation, rough crushing and other equipment, as well as the total cost of the mine. 3. ** Mining and loading work **: The mining and loading process of the hydraulic excavator was to prepare the working face, place the excavator in place, place the vehicle, load the vehicle, and load the vehicle out (the bulldozer assisted in the maintenance of the working face). In actual dispatching, it involved the cooperation between the mine car and the excavator, and there were many common dispatching methods. 4. ** Transportation work **: It is the follow-up process of the mining and loading operation. The basic task is to transport the ores that have been loaded into the transportation equipment to the crushing station or the heap soaking field, and the waste rocks to the waste rock field. The available transportation methods include dump truck transportation, railway transportation, belt transporter transportation, slope skip lifting transportation, and combined transportation formed by various methods (such as dump truck-railway combined transportation, dump truck-belt transporter combined transportation, dump truck (or railway locomotive)-slope skip combined transportation). At present, railway transportation is rarely used. 5. ** Rock discharge (soil discharge)**: When open-pit mining is used, the topsoil or rock covering the upper part of the deposit must be stripped to expose the ore. Therefore, soil discharge is an essential production link in open-pit mining. To collect and transport the stripped topsoil or rocks to a designated place and dump them in a certain way and according to the requirements (the place where the discarded rock and soil are stored is the dump), reasonably select the location of the dump, improve the dumping process and improve the efficiency of the dumping work, which not only affects the technical and economic effects of transportation and dumping, but also involves the occupation of farmland and environmental protection. Sometimes, the waste soil of the temporary dump can be mixed with high-grade ores for neutralizing to improve the economic benefits. If you want to know more about the follow-up, click on the link and read it!
What does it mean to open a new pit in the novel?
In novels, creating a new plot usually referred to creating a new plot or unfolding one of the plots and starting a new chapter. This kind of behavior was often seen as a continuation of an existing work or a continuation of a reader, so it was often called a scam or a continuation. It was a common phenomenon to create a new plot, character, and plot in the process of writing a novel, and to reimagine the entire story line. This kind of behavior could also attract more readers to pay attention to their works. Of course, there were some. No matter which method he chose, it would be a loss for him.
What does it mean to open a new pit in the novel?
In novels, creating a new trap usually meant that a new storyline or character setting would form a new storyline and bring a new experience to the readers. Sometimes, a new trap would suddenly be opened to allow the character to continue developing, and the plot would also unfold. Doing so could surprise and anticipate the readers, and at the same time, help them. However, sometimes a new plot could be created because they needed to take a break or reimagine the story. Under such circumstances, opening a new pit could also be seen as a kind of creative adjustment. New traps in novels could bring new surprises and experiences to the readers as well as help them.
What does it mean to open a new pit in the novel?
A new plot in a novel usually meant that the author suddenly stopped writing and started a new story at the climax of the novel. The new story usually had some connection with the previous story, but it would also change a lot. This style of writing was usually used to make the novel more colorful, and sometimes to make the readers feel fresh. However, there were also times when authors would create a new scam just to make money, not caring about the quality of the novel.
What does it mean to open a new pit in the novel?
Creating a new plot in a novel usually referred to the author starting a new storyline based on the existing plot of the novel and forming a new storyline. The purpose of creating a new pit was to give readers a fresh reading experience, make the story more colorful, and at the same time, bring more inspiration and motivation to the author. Usually, a new story would be more interesting than the existing one and attract the readers 'interest. It might continue the development of the existing story or continue to be written on the basis of it. However, there might be some problems with creating a new story. For example, the author might make negligence, mistakes, or shortcomings in the creative process, causing the new story line to be incoherent or incomplete. In addition, new works might also affect the progress and ending of existing works, causing unnecessary trouble for readers.