Thoughts on Upgrading the Ore Drawing Scheme of the Coarse Crushing Chamber in Dahongshan Iron Mine

Dahongshan Iron Mine is a large-scale mine under construction in southwestern China. It is an important raw material base for Kunshan Iron and Steel Group, with a designed comprehensive production capacity of 4 million ∥a. After years of construction, 600,000 m3 of infrastructure projects have been completed. In order to build Dahongshan Iron Mine into a first-class advanced mine in China, Meishan Iron Mine has carried out technical services for this mine since 2003. Together with Kunming Nonferrous Design and Research Institute and Dahongshan Iron Mine, it will affect the future of the mine. The major key technical issues of production and development were discussed in depth, and improvements and optimization were carried out. In the technical service in 2004, the main research work was carried out on mine roof control technology, mine ventilation technology, and improvement of stage transportation level production capacity.
1 Mine status and existing problems
1.1 Current status of coarse crushing system design Whether the mine’s coarse crushing system operates smoothly and efficiently is related to whether Kungang Dahongshan Iron Mine can achieve a production capacity of 4 million ∥a raw ore. The technological process of the Dahongshan Iron Mine’s transportation system and the slipping system is as follows: the ore is drawn through the vein pass. 10 m3 mine truck transportation, 28 unloading station to unload the upper ore bin for storage, the ore gyratory crusher crushes the lower ore bin for storage, and the ore is transported to the surface by a belt. In the preliminary design of the mine, an imported 42-inch gyratory crusher with compact size, lighter weight, better product quality and performance was selected, and a combination of chain hammer type gate and vibrating ore feeder was used to feed the upper ore bin. . That is: the ore in the upper ore bin flows through the 500 chute to the bottom plate of the 400 chain hammer type ore gate, and the combination of the chain hammer type gate and the vibrating ore discharge machine realizes the feeding of the gyrating crusher. As shown in Figure 1.

1.2 Design of the main problems existing in
the design and use of chain hammer shutter vibration drawing machine 2 sets of discharge means to complete the mineral composition gyratory crusher of the ore, following major problems:
(1) complex production process, System coordination is difficult. Chain hammer gates and vibratory drawing machines are commonly used ore drawing facilities in mine production. These two facilities that can be used to perform ore drawing are combined to complete an operation process. There is a duplication of functions in the process of drawing ore. There are problems of mutual interference and mutual restraint. As long as a set of equipment fails, the entire system will stop running. Increasing the frequency of equipment failures, affecting mine production capacity. The vibrating ore drawing machine in the original design only played the role of transferring ore, and the advantages of the vibrating ore drawing machine were not brought into play.
(2) The flow range of ore drawing is small, which is easy to cause blockage of the chute. Under normal circumstances, fine ore accumulation will appear on the front of the chute when the ore is drawn, forming a dead corner of the ore. Generally, the accumulation angle is 70. about. The original design of the coarse crushing upper ore bin is the same as that of the chute. With the increase of the ore volume of the ore bin and the prolonged use time, the fine ore will accumulate on the chute floor in the ore bin to form a new ore-sliding slope. The vertical distance between the inclined plane and the eyebrow line is shortened, and the chute will be blocked when a few large blocks appear at the mouth of the mine.
(3) Gravity drawing is prone to runaway phenomenon. Chain hammer gate drawing is a gravity gravity drawing method. When the water content of the raw ore is large and there are more mud or fine ore, the problem of ore running is prone to occur; when the chain hammer gate and vibration drawing machine are used to draw ore When the method of discharging ore, the attributes of self-exile ore have not changed, and the problem of ore discharging will also occur.
(4) The processing work carried out after the ore discharge port is blocked, there are still problems such as difficulty in processing. In view of the above problems, it is necessary to optimize the design of the upper ore bin.
2 Design Optimization
2.1 Optimization of the main content
optimization scheme using vibration drawing machine upper mine ore bin balancing discharged, flows through the helical chute opening by mineral crusher, an ore reduction control means, a simplified upper bunker Management of ore release. The main points of the optimized design plan are as follows:
(1) The vibrating ore draw machine is directly installed at the bottom of the upper ore bin, so that the vibrating ore draw machine directly acts on the ore in the ore bin. This can effectively prevent blockage of the mine bin. The installation angle of the vibrating table is 15
(2) A chute is installed below the vibrating table to connect the vibrating table and the gyratory crusher. The installation angle of the inclined chute is set to an adjustable type (preliminarily determined to be 30), and it is changed to a fixed type after production debugging.
(3) The plan optimization work is carried out on the basis of the original design, and the relevant parameters in the original design need to be modified according to the above ideas, and the corresponding excavation engineering quantity is determined based on this (Figure 2).

Several different designs 2.2 Comparative quantities
calculated, original design and optimization scheme quantities shown in table 1. 

2.3 Problems to be paid attention to in the application of the optimization plan
(1) Develop a management system for coarse crushing and vibration ore drawing, strengthen equipment maintenance and maintenance, and implement spot inspections and regular repairs for this part of the equipment. The manganese can be determined based on the experience of other mines. The replacement cycle of steel plates. The Meishan Iron Mine uses heavy plates to feed the ore, and the steel plates are not worn. At this point, Dahongshan Iron Mine can learn from it. Dahongshan Copper Mine has not been replaced since it was put into operation.
(2) It is very necessary to control large blocks in the stope. The mine should strengthen the control and management of the large blocks in the mining area, and try to deal with the large blocks in the mining area; at the same time, in order to strengthen the management of the chute, the mine should formulate the mining area chute The management is standard, and it is strictly forbidden to go down the well in large blocks. Despite this, there will still be a small amount of large blocks entering, which must be processed in the subsequent production process. It is an effective method to set up a large block processing chamber at the transportation level.
(3) Enhancing the predictability and planning of the work can well solve the work that has an impact on mine production such as replacing the vibrating table board and the chute liner. For example: Determine to repair or replace the vibrating table in a certain month. When preparing the mine production plan, consciously arrange the raw ore output for this month to be a little lower to free up the time for shutdown and repair to ensure the normal progress of the repair work.
(4) In many domestic mines, vibration drawing has been promoted and applied in chute drawing and ore bin drawing. Some mature experience can be used for reference in the construction of Dahongshan Iron Mine.
2.4 Prediction and evaluation of the effect of the optimized scheme
(1) The original chain hammer type and vibration drawing equipment are changed to a single “vibration drawing + inclined chute” drawing process, which simplifies the upper silo process The management link avoids the mutual restriction and interference between the two sets of devices, which is beneficial to the mine to increase the mining production capacity.
(2) The upper ore bin adopts the vibration drawing technology, the newly added excavation works are not much, the construction cost is low, and the purpose of simple operation and maintenance is realized. It can effectively solve the problems of ore running and scattering, and can Reduce the labor intensity of production workers.
(3) The vibration drawing method is easy to realize quantitative and stable ore feeding, which is beneficial to realize the automation of the ore drawing process.
(4) The revised design scheme (especially scheme 2) greatly increases the effective volume of the upper ore bin (about 220 m3), increases the storage capacity of the ore bin, and improves the buffer capacity of mine production.
3 Conclusion
(1) In the construction of large-scale underground mines, great attention should be paid to the configuration of system capabilities, and sufficient room should be left in the design. The influences of ”are often superimposed on each other, and sometimes they even appear to be amplified.
(2) Since the key processes in the mining process have a greater impact on the mine production capacity, the design should pay great attention to the technical selection of key processes, carry out technical and economic comparisons of multiple schemes, systematically analyze the advantages and disadvantages of each scheme, and choose a simple process Feasible optimization plan.
(3) For engineering projects and product production processes, short process solutions with simple structure and convenient control should be adopted as far as possible to reduce process control links, improve production efficiency and mine economic benefits.

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