Fine mining of open pit mines

First, fine production

The automotive industry has experienced a tremendous development from extensive production to fine production. The extractive industry should also enter this stage of development.

(1) The basic meaning of fine production

Fine production originated in Japan. In a general sense, fine production means less use of all resources and high utilization of all resources. Resources, including land, mineral resources, raw materials, materials, equipment, personnel, time and money and so on. Fine production mainly includes two aspects: one is to rationally occupy resources, eliminate all the waste of resources (mainly including materials and labor); the second is to optimize the process arrangement and save manufacturing time. In the production and manufacturing process, the reasonable arrangement of resource occupation mainly refers to the minimum inventory of raw materials, the lowest inventory in the case of normal production; the minimum idle amount of semi-finished products, the fastest flow rate of semi-finished products in the case of normal production, the stagnant time The shortest; zero inventory of finished products, realizing instant production and sales. The saving manufacturing time mainly refers to the design of the process and the reasonable layout of the working place. The processes of different natures can be operated in parallel, and the process can be connected reasonably, so that the total manufacturing time is the shortest, and the material consumption is the lowest, the material occupation is the lowest, and the labor input is the most reasonable.

The subtle meaning also includes quality, because high-quality products can provide better function, more reliable performance and longer service life under the same consumption of materialized labor and living labor.

(2) Basic principles of fine production

The basic principles of fine production include eliminating waste, continuous improvement, collaborative work and communication.

1. Continuous improvement

This is the guiding ideology of fine production. Improvement is never satisfied with the status quo, constantly discovering problems, finding reasons, proposing improvement measures, changing working methods, and improving the quality of work. Improvement is a gradual progress, a subtle change, and the process is continuous, accumulating, and everyone must work hard.

2, eliminate waste

Eliminating the waste of resources is the goal of fine production. Anything that exceeds the absolute minimum of materials, machinery, and human resources necessary to increase product value is a waste. The relative occupation of resources and the use of resources can only be made. For inventory and quality, absolute criteria can be given: zero inventory and zero defects. Zero is represented here as a limit that can be infinitely close to it, but it can never be reached. "Double zero" makes improvement never ending.

3, work together

Collaborative work is the way in which people with different careers and expertise are organized to perform specific tasks in the form of small groups. Collaborative work simplifies coordination and can focus on the opinions of people with different professions and expertise, thus improving the quality of work and efficiency, and making improvements continue. Operators, maintenance workers, engineers, and management personnel work together to solve problems on the spot quickly; designers, process personnel, sales personnel, and management personnel work together to enable parallel engineering to be realized, and the new product development cycle is greatly shortened. .

4. Communication

Communication between personnel, departments, and between the company and customers and suppliers requires communication and timely communication to understand each other and work together. Each member of the group must understand the professional and work content of other members, have a common language, put their work into consideration, and avoid one-sidedness.

Working together and communicating is a guarantee for achieving fine production.

(3) Main contents of fine production

The main content of fine production includes factory site management, new product development, relationship with users, and relationship with suppliers.

1. Factory site management

The factory site organizes production on a just-in-time basis, that is, provides what is needed at that time, and exposes management problems by continuously reducing inventory to continuously eliminate waste and make continuous improvement. It involves product design, production planning, machine modification, equipment re-arrangement, process synchronization, equipment maintenance, production organization and labor organization adjustment, personnel retraining and other aspects.

2. New product development

Continuous development of new products is a major factor in creating a competitive advantage, and shortening the development cycle is the key to successfully launching new products. The experience of Japanese companies is to bring together people from various departments of market assessment, production planning, design, process, and production management to set up a new product development team. The group leader has a lot of power. Although the members maintain contact with their respective functional departments, their work is completely under the control of the group's responsible person, working together and communicating with each other, so that many tasks are carried out in parallel, greatly shortening the development cycle.

3, the relationship with the user

"Customer first" and "user first" are the guiding ideology of the company's handling and users. Take a proactive attitude, engage in "main sales", take the initiative to go to the door to understand the situation, solicit opinions, and carry out pre-sales and after-sales services.

4. Relationship with suppliers

The supply plant and the assembly plant are cooperative. In the initial stage of new product development, suppliers can participate in the organization, according to the different tasks, the suppliers are organized according to different levels. When determining the price of a component, the assembly plant determines the target price of the car according to the market conditions, and then considers the reasonable profit with the supplier to calculate the target cost of each part. In order to achieve the target cost, both parties use value engineering methods to identify each factor that can reduce costs. Suppliers are able to proactively reduce costs because lowering costs can bring them more profit.

Obviously, the principle of fine production in the automotive industry is applicable to the extractive industry.

Second, fine production and open pit mining

In the past, the exploitation of open pit mines at home and abroad was basically extensive. The separation of waste rock in the mining process, the mining of ore, the transportation and discharge of ore, the maintenance of slopes, the reclamation and greening of waste rock fields, etc. Most of the links are relatively independent, independent design, construction and management. The guiding ideology is to meet the capacity requirements between the upper and lower process links and reduce costs.

Open pit mining is usually carried out continuously from one end to the other, forming a large range of geotechnical disturbances and ground environmental damage. The final slope formed during the mining process may exist for several years or even decades. A large amount of slope maintenance work is required, which requires a lot of money, and engineering geological disasters such as landslides may occur. For mines with waste rock drainage conditions, the discharge of waste rock is generally carried out. This type of emissions is mainly considered to save the cost of waste rock transportation and to discharge them in turn.

With the advancement of science and technology, the social division of labor has become more and more refined, and the degree of specialization has become higher and higher. The extractive industry has already entered the era of fine production. There are many common grounds between mine production and factory production, and there are some obvious differences. The workshops and equipment of the factory are usually fixed, and the processed articles are processed through the equipment, and the process is standardized. The mining stope of the mine is continuously promoted, and the main mining equipment also needs to move synchronously, and due to the geological conditions and mining technology of the deposit. Complexity involves a large number of problems such as production exploration and boundary delineation of rock deposits, formation stability control and production safety, process optimization and rational production scheduling. Therefore, the fine mining of mines will involve a wider range of scientific and technical issues.

Third, the guiding ideology of fine mining in open pit mines

The fine mining of open pit mines is to minimize the damage of open pit mining environment, the transportation of rock and rock, the amount of slope excavation and the maintenance workload. Through the fine mining and fine mining process, combined with fine production management, to obtain the best mining economic, environmental and social benefits.

The patented technology “Open-pit mining technology for rapid dumping and ecological restoration” (patent number: ZL 2006 1 0019707.2) is one of the core technologies for fine mining of open pit mines. At the same time, it is necessary to make full use of the theory and methods of mine system engineering, mine environmental engineering, restoration ecology, soil and water conservation engineering, botany, computer science, management science, etc., to deeply study the internal relationship of open-pit mining process links, and propose new optimization. The combination process shortens the cycle time of the operation and restores the ecological environment as soon as possible, achieving the goal of greatly reducing production costs and protecting the environment.

(1) Open pit mining system and process research

Open-pit mining is a complex and large system. It provides mineral resources to human beings while continuously destroying the surrounding ecological environment, causing desertification and even geological disasters such as landslides and mudslides. To this end, human development of mineral resources must be coordinated with the protection of the environment. The system contains many interrelated subsystems. From the perspective of the system, it is necessary to use operational research theory to study various process links, optimize them, shorten the operation cycle time, and mine ore at the lowest cost to achieve the best environmental protection.

(II) Research on slope maintenance theory and technology

After the final slope is formed, the strength and stability of the slope gradually decrease with time under the influence of production blasting and weathering. Therefore, the process of minimizing the duration of the final slope is studied to appropriately increase the steep slope angle, thereby reducing the stripping ratio and the maintenance workload of the slope, avoiding geological disasters and reducing production costs.

(III) Research on slope protection materials and methods

There are many methods for the treatment of unstable slopes in traditional open pit mines. Commonly used are cut slope tops and pressure slope feet. For mines that have the conditions for the discharge of waste rock in the goaf in open pits, the waste rock is used as the slope protection material, and the waste rock slope is used as the main slope protection method, and the traditional “pressing foot” is developed to “press the waist”. "Pressing the chest" or even "pressing the face", as soon as possible to eliminate the possibility of the final slope of the temporary slope, and quickly achieve the purpose of permanent governance of the slope.

(IV) Research on the minimization of disturbed damage in open pit mining

Change the traditional large-scale stripping and mining methods, and make the stripping and mining in the smallest possible range on the premise of meeting the production process requirements. Once the mining of the range is over, the scope is quickly rehabilitated and environmentally rehabilitated to restore the environmental ecology.

(V) Research on material transportation minimization

The amount of waste rock and ore transported in open pit mines is very large, and the discharge of waste rock from the waste rock is realized as much as possible. It is used to close the slope and use the method of operations research to minimize the total transport work of the rock.

Fourth, open mining fine mining technology

The fine mining technology of open pit mine is: in the mine with the inner stripping waste rock condition, the initial stripping and mining is carried out in one or the middle part of the open pit mine by conventional methods; once the initial stripping and mining is completed, in the direction of mining mining advancement Divide the mining face into left-hand zone, middle zone and right-hand zone, and further divide them into several smaller sections; take the section as the mining unit, and gradually carry out stripping, mining, backfilling, and backfilling Reclaiming greening or concrete coverage; taking the near-discharged waste rock as the main final slope permanent treatment method, reducing production costs and quickly restoring ecology.

The steps of the process are:

1 In the end or middle part of the ore body, the waste rock is stripped by conventional methods, the waste rock is discharged to the outer dumping field, and the stripped ore body is mined to form an initial stripping working surface that meets the minimum size required by the process (Fig. 2). . 2 In the direction of picking and stripping, divide the stripping range into left-left, middle and right-cut areas (Fig. 3). Under the conditions of meeting the minimum size required for stripping operations and the optimal technical and economic indicators, The area is divided into several segments. 3 Firstly, the first section of the left and right gangs will be stripped and mined. The stripping of the first section of the central area will be followed up by the mining. The stripped waste rock will be discharged inside the pit goaf for the open pit mine. The slope and the slope of the two side slopes are pressed from the foot of the slope to the top of the slope, and the permanent slope protection of the rear slope is completed as soon as possible. 4 For each segment that completes the permanent treatment of the final slope, immediately reclaim the greening or covering the concrete to restore the ecology. The second step is to carry out the stripping and mining of the second section of the left and right gangs. The stripped waste rock is used for the slope backfilling of the first section slope, the middle section stripping and mining are moderately followed, and the stripping waste rock is used for The back of the rear goaf is backfilled, and the backfilled section is immediately reclaimed to green or cover the concrete to restore the ecology. 6 From the second step, enter the normal production cycle, and then advance in stages until the mining is completed, and the ecological restoration is completed.
For the mine that forms the initial mining and stripping working face from the middle of the deposit, two stripping working faces can be formed, and the above process is used to push forward.

5. Advantages of the fine production process of open pit mines

The waste rock discharge distance is short and the transportation cost is low; the final slope has a short time, so the final slope angle can be increased to reduce the amount of waste rock stripping; the dumping slope is the main means of slope treatment. Combining the rapid and final treatment of the soil with the final slope, the cost of slope treatment is low, and the occurrence of slope geological disasters can be avoided as soon as possible; the damage of the extensive open rock mass excavation to the surface environment is reduced to small points. The local destruction of the segment achieves the goal of minimizing the scope of environmental impact; quickly recovering the ecological environment and achieving the shortest environmental impact time, and maximizing the low-cost environmentally friendly green mining of open pit mines.

Obviously, the theory and technology of fine mining is applicable not only to open pit mining, but also to underground mining, open pit and underground joint mining and special mining.

Conclusion

(1) The principle of fine production is suitable for today's mining industry, and the extractive industry should enter the stage of fine production.

(2) The fine mining of open pit mines is to minimize the damage of open pit mining environment, the transportation of rock and rock, the amount of slope excavation and the maintenance workload, and to achieve the best through the fine mining and fine mining process. The economic, environmental and social benefits of mining.

(3) It is necessary to make full use of theories and methods of mine system engineering, mine rock mechanics, mine environmental engineering, restoration ecology, soil and water conservation engineering, botany, computer science, management science, etc., to innovate in slope maintenance theory and methods. In-depth study of the internal linkages of the open-pit mining process, propose a new optimized combination process, restore the ecological environment as soon as possible, and achieve the purpose of significantly reducing production costs and protecting the environment.

(4) The fine mining technology of open pit mines can be summarized as follows: in mines with internal stripping waste rock conditions, the ore bodies are divided into small mining units that are reasonable in process, and stripping, mining, backfilling and backfilling are carried out step by step.垦 Greening or concrete coverage, with the discharge of waste rock near the discharge slope as the main final slope permanent treatment means, shorten the operation cycle time, reduce production costs, and quickly restore the ecological environment.