Diameter of drawing machine

1. If you choose the one with high income, good security and independent data center, interstellar cloud is a good choice.

2. First of all, you should be proficient in mining machinery procts, including its working principle, proct use, vulnerable parts, precautions for use, model specifications, etc
secondly, you need to have certain communication skills, so that your sales request is not abrupt and customers are willing to accept it
in the end, you must love sales and interest is the best teacher. Only when you really like this job can you do it well.

3.

Wang Chonglun once served as the chairman of Angang trade union, vice chairman of all China Federation of trade unions and Deputy Secretary of Harbin municipal Party committee

Wang Chonglun, born in poverty, worked as an apprentice in Zhaohe iron and steel plant before liberation. In March 1949, he worked as a planer in the tool workshop of Angang machine repair plant. He joined the Communist Party of China in 1952

he successively served as deputy director of workshop, deputy director of Angang Shuangge office, leader of Angang trade union preparatory group, etc. ring the first five year plan period, innovators were praised as pioneers

he was successively elected as a deputy to the first, second, third, fourth and Fifth National People's Congress, a deputy to the tenth and Twelfth National People's Congress, a member of the Twelfth Central Committee, a member of the Seventh National Committee of the Chinese people's Political Consultative Conference, a director of the National Technical Cooperation Committee for workers, and a vice president of the China Invention Association

extended materials:

in order to make the work of the workers' Technical Association better serve the central work of the whole party, Wang Chonglun organized relevant parties to discuss the emergence, development, experience and lessons of the work of the workers' Technical Association in China for many times, and put forward measures to improve the work of the workers' technical association under the new situation. As a result, the National Technical Association of large and medium-sized enterprises has carried out paid service work one after another

the implementation of this measure has injected new vitality and vigor into the activities of the staff technical association. Wang Chonglun's overwork for a long time has damaged his original strong physique

In May 1985, Wang Chonglun was suddenly numb and his words were not clear, so he was escorted to the hospital by his comrades. After being diagnosed with cerebral thrombosis, the hospital decided to carry out systematic treatment. Wang Chonglun only lived in the hospital for one course of treatment and then put himself into the intense work

On February 21, 2002, the farewell ceremony for the remains of Comrade Wang Chonglun was held at Babaoshan Revolutionary Cemetery in Beijing. Li Ruihuan, Wei Jianxing, Luo Gan and other comrades attended the farewell ceremony

according to Comrade Wang Chonglun's wish before his death, under the arrangement of relevant departments, on March 13, part of Wang Chonglun's ashes were buried in the meritorious service garden of Qianqiu cemetery at the foot of Qianshan Mountain, which ended this old model's homesickness for many years

4. 3、 The lamp room should be well ventilated; No fireworks are allowed in the lamp room and warehouse, and fire-fighting equipment should be provided; 4、 In the safety light room, there should be a separate room and exit for the installation of lamp oil and the work of sending and receiving lamps; The gasoline storage capacity in the lamp oil loading room shall not exceed 40 liters and shall be properly kept. Article 393 special apparatus must be used in the preparation and filling of electrohydraulic fluid. The staff must wear protective glasses, masks, rubber gloves, Rubber Aprons and rubber shoes. For storage and blending of electro-hydraulic fluid, it is necessary to use porcelain, glass or other containers without chemical change of electro-hydraulic fluid. When mixing acid electrohydraulic, only sulfuric acid should be poured into water, and it is forbidden to pour water into sulfuric acid. There must be a solution for neutralizing electrohydraulic in the room for use in electrohydraulic cauterization. Article 394 telephones shall be installed in underground car yards, transportation dispatching rooms, main electromechanical chambers, health stations and mining areas. Underground main pump room, substation and ground fan room telephone, to have direct contact with the ground central exchange or control room. Article 395 it is forbidden to use the earth as a loop for underground telephone lines. The transport signal device can be powered by motor frame line or lighting line. The motor frame line can be used for high frequency communication. Article 396 electrical signals must meet the following requirements: 1. Electrical signals in mines shall generally be able to emit sound and light at the same time. The types and uses of signals should be revealed near important signal devices; 2、 The signal device of lifting personnel and main wellhead winch shall be powered by special line; 3、 Between the water gun driver and the coal pump driver, the high-pressure pump driver and the dehydration screen driver, the signal and telephone with both sound and light should be installed. Section 6 protective earthing Article 397 the metal enclosure of electrical equipment which may have dangerous voltage e to insulation damage must be earthed. All equipment that must be grounded (including the shell of armored cable, lead sheath and grounding core wire of rubber cable) and local grounding device shall be connected with the main grounding grid. The grounding core of rubber cable shall not be used for other purposes. For the protective grounding of electrical equipment, the staff on ty shall conct a surface inspection every shift. Underground grounding protection work shall be carried out in accordance with the regulations of the detailed rules for installation, inspection and measurement of mine grounding protection device. Article 398 provisions on the installation site of grounding electrode: 1. When there are several levels in the mine, the main grounding grid of each level shall be connected with the main grounding device. The main grounding electrode shall be embedded in the sump, and one for each sump. The main grounding electrode shall be made of steel plate with an area of not less than 0.75 square meters and a thickness of not less than 5 mm, on which a section of flat steel shall be welded to connect the lead wire; 2、 The local grounding electrode can be set in the tunnel ditch or other wet places. For the grounding electrode set in the tunnel ditch, steel plates with an area of not less than 0.6 square meters and a thickness of not less than 3 mm or steel pipes with the same effective area shall be placed horizontally in the depth of the ditch; For the grounding electrode set in other places, iron pipes with a diameter of not less than 35 mm and a length of not less than 1.5 m can be used. At least 20 through holes with a diameter of not less than 5 mm shall be drilled on the pipes and buried vertically in the ground; 3、 If the cable laid in the borehole cannot be connected with the general grounding grid of the mine, the general grounding electrode of this part shall be set on the ground. Article 399 locations where local grounding electrodes are required: 1. Each chamber with fixed electrical equipment and a separate high-voltage switchgear; 2、 Substation and working face distribution point in mining area; 3、 Connect each junction box of the power armored cable. The junction box of fixed lighting equipment in the roadway can be grounded on the spot every 100 meters or so. Article 400 the lead section used for connecting the main grounding electrode and the main grounding grid shall be copper wire of not less than 50 square mm or flat steel or galvanized iron wire of not less than 100 square mm. For the connection between the shell of electrical equipment and the general grounding grid or local grounding, as well as the grounding lead section for the connection of the armor and lead skin of the cables at both ends of the cable junction box, copper wire of not less than 25 square mm or flat steel or galvanized iron wire of not less than 50 square mm shall be used. Article 401 the transition resistance of the main grounding grid shall not exceed 2 ohm from the main grounding electrode to the farthest local grounding device. The resistance of grounding wire between each mobile electrical equipment and the main grounding grid or local grounding shall not exceed 1 ohm. Section 7 inspection and repair article 402 the inspection, maintenance, repair and adjustment of electrical equipment shall only be carried out by a dedicated or temporarily appointed electrical repairman. For electrical equipment with voltage over 700 V, a work ticket is required for the above work. Under special circumstances, electric fitters in mining area are allowed to switch on or off the electrical equipment with voltage over 700 V in the substation, but they are not allowed to open the electrical equipment for repair without authorization; The shutdown and power supply of important lines and important workplaces must be carried out by designated personnel with work tickets. Article 403 the electrical equipment whose explosion-proof performance is damaged shall be repaired in accordance with the detailed rules of this regulation "repair regulation for enclosure of explosion-proof electrical equipment in coal mines". After repair, it can only be used after being accepted by inspectors. Article 404 the following main inspection system shall be established for each mine, and the inspection results shall be recorded in a special record book. Problems found in the inspection shall be handled by a special person designated by the person in charge of the mechanical and Electrical Department of the mine.

5. 1. Overview

1.1 main technical features and uses
6m3 bottom side mp car is a kind of special equipment used in underground mine roadway transportation operation system. Its unique structural design makes the car integrate transportation and unloading functions. The 6m3 bottom side mp car developed by our company has the advantages of stable operation, high bearing capacity, accurate unloading meshing track, high load-carrying capacity and low cost It is rable and easy to use and maintain
this equipment is mainly used for ore transportation and unloading in underground roadway or open pit of metallurgical mines

1.2 model composition and its representative significance
the track gauge of 6m3 bottom side mp tramcar is 900mm, and the model is ydcc6-9, where y stands for metallurgical mine, DC stands for bottom side mp tramcar, C stands for tramcar, and the two digits behind represent carriage volume and track gauge respectively
for example, ydcc6-9 refers to the bottom side mp car for metallurgical mines, with a carriage volume of 6m3 and a suitable gauge of 900mm

1.4 executive standard
executive standard of the equipment: JB / t5498-91

2.2 structure description of main parts

2.2.1 carriage
carriage is an important part of the tramcar, which is mainly used to hold ore. when the tramcar carries ore and unloads ore, the carriage bears multi-directional dynamic load
therefore, this part is made of Q345 steel plate and profile, especially for the parts of important parts, the whole steel plate bending process is adopted, so as to fully ensure that the car has enough strength and stiffness
in order to facilitate the continuous loading of ore by trams and improve the transportation efficiency, the structure of the carriage is designed to be overlapped to ensure that the two adjacent trams can be overlapped well. Both ends of the car body are connected with the buffer box by bolts

2.2.2 frame
this part is a structural part, which is the main bearing part of the tramcar
in order to make this part have enough rigidity and strength, it is made of profile and steel plate by welding, and the unloading wheel is installed at the lower side of the middle of the frame

2.2.3 axle part
this part is composed of steering mechanism, spindle, bearing, miner wheel, sealing cover and other parts
the purpose of using the steering mechanism is to fully adapt to the working characteristics of large and medium-sized tramcars, so that the tramcar can turn well when passing the curve, and rece the wheel wear. The special articulated steering mechanism adopts special design, which fully takes into account the strength and structural technology, and has sufficient mechanical properties, convenient maintenance and repair, etc, All kinds of dynamic complex impact loads proced by tramcar running, especially on curved track, are adjusted and steered in any direction
the automatic steering rotary control reset mechanism has been strictly calculated and designed to maintain higher working reliability of the steering mechanism
the main shaft is made of No.45, and the tramcar wheel is made of high-quality engineering cast steel. The rim of the tramcar wheel is 1:20 tapered, so that the tramcar can run along the track center. The rim gauge of the installed tramcar wheel is compatible with the track gauge
the bearings are made by well-known manufacturers to ensure the reliability of bearing quality
the labyrinth seal structure is included in the seal cover, which makes the bearing get good lubrication and seal

2.2.4 automatic hook
this part is an important part of the tramcar. Strict materials, manufacturing technology, detection and test methods are adopted to ensure safe and reliable operation
this part adopts the form of automatic hook. After several improvements, it can effectively buffer the additional impact force when the tramcar collides, and has the characteristics of reliable automatic connection

2.2.5 unloading wheel
the main function of this part is to contact with the curved rail when the ore is unloaded, and the meshing track of the working surface of the unloading wheel and the curved rail surface makes the bottom door of the car turn over, so as to realize the ore unloading
the unloading wheel is installed on the side of the chassis. The processing and installation position of this part meet the working requirements of the ore car when unloading, and it has the characteristics of flexible and reliable rotation

2.2.5 hinge mechanism
the main function of this part is to connect the carriage and the frame. When the ore car is unloaded, the bottom door of the car will open automatically and rotate around the center of the hinge mechanism. When working, the hinge mechanism should be flexible and reliable
the pin in the hinge mechanism is a key part, which is directly related to the safety of the ore car when unloading. Therefore, strict materials, manufacturing technology, detection and test methods are adopted for the pin to ensure the safety and reliability of the work< br />
3、 Technical performance of equipment
serial number, name and specification remarks
1 specification and model ydcc6-9
2 geometric volume (M3) 6
3 maximum load capacity (kg) 16000
4 maximum traction (kg) 6000
5 total length (mm) 5000
6 maximum width (mm) 1800
7 height (mm) 1660 from rail surface
8 gauge (mm) 900
9 wheelbase (mm) 2000
10 wheel diameter (mm) Ф 420
11 diameter of unloading wheel (mm) Ф 350
12 dead weight (kg) 7600
13 connector center height (mm) 725 from the rail surface
14 bottom side unloading
15 executive standard JB / t5498-91

4, equipment installation, debugging and trial operation
in order to facilitate users to directly transport the tramcar to the proction site, the installation personnel can remove the pin in the hinge mechanism to separate the carriage from the frame, Then the carriage and frame are respectively placed on the transport cage or ramp special vehicles for transportation
in order to make it easy for users to directly understand the use of 6m3 bottom side mp tramcar, the tramcar manufacturer is attached with the general drawing of the tramcar, the assembly drawing of the main structure, and relevant technical documents<
4.1 preparatory work
4.1.1 prepare a site with good lifting facilities
4.1.2 lay the required 900 gauge track.
4.1.3 place the 6m3 bottom side mp tramcar on the track
4.2 check
4.2.1 check the accompanying tramcar technical instructions
4.2.2 check whether the tramcar shape is intact
4.2.3 check whether the lubricating oil of each lubrication part of the tramcar is sufficient
4 2.2.4 check whether the fasteners of the connection parts of the tramcar are connected reliably
4.2.5 check whether the hook height of the connection between the tramcars is consistent
4.3 debugging and test run
4.3.1 connect the tramcar with automatic hook
4.3.2 electric locomotive traction tramcar group driving
4.3.3 the tramcar should run stably and reliably without noise Impact, etc.
4.3.4 all rotating parts should be operated flexibly, without collision, scratch, clamping, etc.
4.4 transportation
4.4.1 the user should determine the transportation scheme according to the actual transportation situation on site
4.4.2 remove the pin in the hinge mechanism, Separate the carriage from the frame
4.4.3 erect the carriage and frame in the cage or place them on the ramp special vehicle
4.4.4 the weight and overall dimension of the carriage are 2840 kg and 5000 mm * 1800 mm * 1225 mm
4.4.5 the weight and overall dimension of the frame are 4528 kg and 3472 mm * 1570 mm * 700 mm
4.4.5 the parts shall not be impacted ring transportation

5 Applicable conditions of ore car
5.1 the distance between the bottom plate of the movable chute of the ore loading gate and the upper end of the carriage shall not exceed 250mm. If the ore is loaded by the vibrating ore drawing machine, it shall be determined according to the specific requirements of the vibrating ore drawing machine
5.2 the running speed V of the ore car at the unloading station can be finally determined according to the proction practice. During the trial proction, v = 0.5m/s can be initially taken. The determination of V is to make V as large as possible under the condition that the minerals in the car can be well unloaded in the unloading station, so as to improve the unloading efficiency
5.3 the structural form of the hook of the 14T electric locomotive, the height from the center line of the hook to the rail surface, the size of the wing plates on both sides of the electric locomotive and the height from the hook to the rail surface must be completely consistent with the mine car

6. Use, maintenance and management
the user department should attach great importance to this work, which includes inspection system, use and overhaul system
6.1 carriage
check the welding condition of each part of the carriage, and no desoldering is allowed. If there is any problem, deal with it in time
6.1.1 it is strictly forbidden to throw ore from high places to avoid cracking the bottom of the box
6.1.2 the car cleaning equipment should be designed according to the actual situation of the user department
6.2 frame, buffer and connecting hook
6.2.1 it is not allowed to slide when the car is fully loaded, and it is not allowed to make the mine cars collide violently
6.2.3 the bumps of the buffer shall not be loose. If they are loose, they shall be reinforced or replaced immediately
6.2.4 the connecting parts between tramcars should be checked every shift, and any abnormality should be handled or replaced in time
6.3 axle parts
6.3.1 the axle parts shall be well lubricated, and a regular oil injection system shall be established as required, and the period shall not exceed 3 months
6.3.2 always check the working conditions of the sealing parts at both ends of the axle to avoid water or mineral mud entering the axle, and deal with problems in time
6.3.3 it is strictly forbidden to insert wooden or iron rods into wheel holes to slow down and stop the tramcar ring operation
6.3.4 check whether the connection between axle part and frame part is reliable
6.3.5 the tramcar used shall be numbered, and the account of equipment use, maintenance and management shall be established. It is strictly forbidden to operate the tramcar with "disease" to ensure the normal operation of the equipment

7. Detailed list of wearing parts
name, specification, model, material and quantity
tramcar wheel Ф 420 zg270-500 8 / each tramcar
unloading wheel Ф 350 45 1 / each tramcar
4 rubber springs are specially used according to the drawing / each tramcar
unloading wheel bearing 32318 standard parts 1 / each tramcar
wheel bearing 22319 standard parts 8 / each tramcar

8. Tramcar painting
before the tramcar leaves the factory, the tramcar has been cleaned before painting, the tramcar has been cleaned, and the antirust primer and top coat have been successively applied, The color of the topcoat is selected by the user and implemented by the manufacturer according to the requirements.

6. I don't have a calculator here. Do it yourself! 42.4 divided by D under the root sign, D is the effective diameter of the ball mill, in meters! The number of times 85% is the best revolution! Tilt angle of 2-4 parts per thousand is OK! I'm Yantai Jinhao miner. If you have any questions, please ask me. My name is QQ

7. The ball diameter of ball mill depends on many factors, such as the particle size, hardness and density of the material, the diameter and speed of ball mill, the density of ball, the concentration of pulp and so on. The feed hammer crusher of grinding machine is composed of different particles of several jaw crushers. Practice has proved that when dealing with hard or coarse-grained ore, a larger impact force is needed and a larger ball should be added; When the ore is softer, the particle size is larger and smaller than that of impact crusher, and the jaw crusher is required to be finer, grinding should be the main method, and smaller balls should be added. Of course, the choice of ball diameter is also related to the diameter and speed of the mill. The ball diameter of the hammer crusher can be smaller with large diameter and high speed. In a word, big ball impact is needed for large ore and small ball grinding is needed for small ore. Although the relationship between the size of less ore without dryer and the diameter of ball to be added has been put forward, because the grinding process is a complex vibrating screen process, each formula has its own limitations and large deviation. The most basic formula is
d = I
where D -- the diameter of the ball to be added, mm
D -- particle size of ground material, mm
I -- property coefficient of ore particle< For medium hardness ore, I = 28, so
d = 28

8.

Caving mining method is a mining method to realize ground pressure management by caving surrounding rock. In the caving method, it is not necessary to divide the mining area (ore block) into two steps of room and pillar mining, but single step mining. Therefore, this kind of mining method eliminates the disadvantages of poor safety conditions, large ore loss and dilution when mining pillars. When adopting caving mining method, the surrounding rock and surface must be allowed to collapse. This book mainly introces sublevel caving with sill and sublevel caving without sill

This method has the following basic characteristics:

(1) the stage is divided into several sections, and the ore is mined section by section from top to bottom

(2) ore drawing, transportation and secondary crushing are all carried out in the special roadway g in the bottom pillar, and the bottom pillar will be mined together with the next section

(3) the surrounding rock collapses naturally or forcibly in the process of mining, and the ore drawing is carried out under the caving overburden

The application of this mining method has accumulated rich experience in China. This method is used in many nonferrous metal mines in Zhongtiaoshan, Tongguanshan and Yunnan

The typical scheme is shown in Fig. 5-5-10. This scheme occupies the most important position in sublevel caving with sill pillar in China. This method divides the stage into several mining areas for mining, and the mining areas are arranged along the strike. The length of mining area is mainly determined by reasonable harrowing distance, generally 25-30m, mostly 40m; The width of mining area is equal to the thickness of ore body, generally 10-15m; The stage height is 50m; The mining area is divided into two sections with the height of 25m and the height of bottom column of 6-8m

The work of mining preparation includes transportation and auxiliary roadway, ore drawing pass, ventilated pedestrian raise, electric rake roadway, trench roadway, douchuan and funnel neck, cutting raise, rock drilling roadway, etc

in the hanging wall of the ore body, one inner vein and one outer vein transportation roadway are arranged respectively in the footwall. In the transportation level, the vein crossing roadway is arranged at the junction of two adjacent mining areas, and the annular transportation system of loading in the vein crossing roadway is adopted. Each section is arranged with an inclined 60 ° Above the pass, straight through the vein roadway. Each 1-2 mining areas is equipped with a footwall external air inlet, pedestrian and material patio, which is connected with the electric rake road of each section by a connecting road. The "V" type trench bottom structure is adopted, and two funnels are arranged with the distance of 5-5.5 m and the slope angle of 50 ° In order to form trench, two trench roadways should be excavated first in each section. The electric rake road and trench roadways are connected by douchuan and bucket neck. The specifications of douchuan and bucket neck are 2.5 M × 2.5 m The vertical distance between trench roadway and electric rake road is 4.5 M. In addition to the trench roadway can be used as rock drilling roadway, each section is also arranged with a rock drilling roadway with a section of 2.5 M × 2.5 m, depending on the drilling equipment

Fig. 5-5-10 sublevel caving mining method with sill pillar for vertical deep hole caving. Cutting of trench: in trench roadway, drill upward fan-shaped medium deep hole and blast corresponding deep hole of upper rock drilling roadway at the same time to form "V" trench once or successively, as shown in Figure 5-13. The blasting parameters are basically the same as the mining parameters of thin ore, but e to the great clamping property of vertical "V" surface, the medium deep holes on both sides should be properly densified, and the low distance of holes should be less than the minimum resistance line. The cutting technology of trench is simple, efficient and easy to ensure the construction quality. However, the trench structure cuts the bottom column severely, which reces the stability of the bottom column

cutting vertical groove is to create a free surface for caving and form necessary compensation space to meet the requirements of crushing expansion of caving ore. The cutting vertical groove should be adapted to the ore caving, and should be opened according to the maximum contour of ore collapse. The position and quantity of vertical trough depend on the shape of ore body and mining plan. The cutting groove is formed by medium deep hole, and only a few mines use shallow hole

At present, medium and deep hole caving and deep hole caving are widely used in the mines with sill pillar sublevel caving in China. The blast hole layout of deep hole caving mainly adopts fan type (Fig. 5-5-11). Fan shaped arrangement means that the holes in a row of blastholes are arranged radially from a certain point (or two points) as the center (called radiation center or radiation point). The hole spacing of the fan-shaped deep hole increases graally from the orifice to the bottom of the hole

the minimum resistance line of blasthole, that is, the distance between rows of blasthole. It is an important parameter of medium deep hole caving. Whether it is reasonable or not is directly related to the quantity of ore collapse per meter blast hole, the yield of large block and the quantity of rock drilling

In practical work, the selection of minimum resistance line mainly depends on the firmness of ore, pore size and explosive type. For example, when the firmness of the ore is high, the aperture is small, and the explosive power is low, the value of the minimum resistance line can be selected smaller, otherwise, it can be selected larger

Fig. 5-5-11 fan shaped deep hole schematic diagram of deep hole caving

according to the data summarized from actual proction experience, the minimum resistance line values currently adopted in the mine are roughly as follows:

Introction to exploration, mining and beneficiation of solid minerals

where D - blasthole diameter, mm; W -- minimum resistance line, M

In terms of blasting technology, some mines have successfully applied the new technology of extrusion blasting, which improves the quality of ore collapse and improves the proction capacity of ore block

squeezing blasting is to squeeze the loose medium of adjacent sections to obtain compensation space or excavate small compensation space for blasting, so as to control the loose coefficient of caving ore within 1.1 ~ 1.2. Due to the small compensation space, the caving ore can not meet the requirements of crushing expansion, so the ore is crushed twice in the extrusion state ring the blasting process. This kind of extrusion blasting method can rece the block yield and improve the ore drawing proction capacity. Generally, the ore is transported by electric harrow, and the harrow distance is 30-40m

The sublevel caving mining method is to lower the ore in the overburden. The caving ore has at least one waste rock contact surface. The mixing and blending of these waste rocks is the main source of ore loss and dilution ring ore drawing, so the ore drawing management is extremely important. Reasonable ore drawing management should make the ore loss and dilution small and the stope ore drawing capacity large. In order to improve the ore drawing index of sublevel caving with sill pillar, the ore drawing should be carried out evenly between the hoppers of the electric rake road ring ore drawing, so as to make the contact surface of waste rock and ore drop evenly. There are two cases: when the burden of ore in each funnel is roughly equal, the equal amount of uniform ore drawing can be adopted; when the burden of ore in each funnel is not equal, the unequal amount of uniform ore drawing can be adopted. At this time, the electric rake road is responsible for the funnel with large amount of ore and releases more ore each time; It is responsible for the funnel with small amount of ore and releases less ore each time

(2) pillarless sublevel caving method

1. Overview the pillarless sublevel caving method was used in Xiangshan pyrite mine of Anhui Province in 1964, and was successfully used in Damiao iron mine of Hebei Province in 1967, and was rapidly promoted in metal mines, especially in iron mines. Decades of proction practice has proved that this mining method has the outstanding advantages of high strength, high efficiency, low cost, simple process, high degree of mechanization and proction safety

in this mining method, not only the top pillar and inter pillar of the mining area are cancelled, but also the bottom pillar with complex structure is removed, which simplifies the mining area structure. The characteristics of this mining method are: in the ore body, generally 10m × The mining roadway is excavated with a mesh of 10m, and the upward fan-shaped deep holes are drilled in the roadway; With the ore caving, the surrounding rock is full of goaf. The ore caving is transported from the end of the mining roadway to the pass under the overburden. Due to the use of rock drilling jumbo, loader, scraper and other mining equipment, it is an efficient mining method

Typical scheme (1) constituent elements and mining preparation layout: the mining preparation roadway of this method includes upper and lower stage transportation roadway, return air roadway, equipment pedestrian ventilation shaft, ore drawing pass, ventilation raise, sectional connection roadway, mining roadway, cutting roadway and cutting raise, etc. (Fig. 5-5-12). As the elements of this method are closely related to the layout of mining preparation, the two problems are discussed together

(2) stage height: this mining method is mostly used for mining steep thick deposits with stable ore, and the stage height is relatively large, generally 60-70m. When the dip angle of the ore body is slow, the occurrence is irregular, and the ore rock is not stable enough, the stage height can be smaller

(3) chute layout and mining area size: in pillarless sublevel caving method, the mining roadway is generally regarded as the mining unit. For the convenience of management, the scope of a chute service is divided into a mining area. Most of the chutes are arranged outside the vein, and the distance between chutes is mainly determined by the capacity of transporting equipment. When zyq-14 is used, the average transport distance is 40-50m and the efficiency is high. When the mining roadway is arranged vertically, the distance between chutes is generally 40-60m; It is 60-80m along the strike. The size of mining area is the same as this. The cross section of the chute is generally 2m × 2 m square pass or 2 m diameter circular pass

Figure 5-5-12 schematic diagram of pillarless sublevel caving method. But the segment height is limited by drilling equipment and ore loss and dilution index ring ore drawing. With the increase of segment height, the depth of blast hole increases, which makes the drilling speed decrease. At present, the sectional height of mines in China is generally 9-15m. Practice has proved that the effect of 9-12M is better

(5) mining roadway layout: when the thickness of ore body is large (above 15-20m), the sublevel mining roadway should be arranged vertically. When the thickness of ore body is small, it can be arranged along strike

mining roadway spacing, that is, the height of a mining roadway, is mostly between 8 and 12m. When the caving ore powder is too much, wet and the fluidity is not good, the center distance of roadway should be smaller. According to the ore drawing law, the upper and lower sublevel mining roadways should be staggered (diamond layout), as shown in figure 5-5-13

Fig. 5-5-13 schematic diagram of raise heading method

the size of mining roadway section should be determined according to the equipment used. From the point of view of recing ore loss and dilution index, it is better to have a larger roadway width, which is concive to ore drawing, and it is also convenient for the loader to load ore evenly in the full width, so as to improve the recovery index. The mining roadway should have a slope of 3% - 5% to facilitate drainage and downhill operation of heavy-ty loaders

(6) the layout of the segmented connecting road: the segmented connecting road can be divided into two kinds of layout modes, i.e. in pulse and out of pulse. In the vein layout, by-proct ore can be obtained, recing the amount of excavation in the rock, but the disadvantage is that mining to the roadway intersection increases the loss of ore, and the work safety is poor. Therefore, the general use of pulse layout is better

(7) arrangement of equipment wells: this mining method has a high degree of mechanization and many sections. In order to transport equipment, materials and personnel up and down between sections, an equipment well can be arranged outside the caving limit of footwall every 150-300m along the strike. Elevator and lifting equipment are installed in the equipment well. The cross section of the equipment shaft is determined according to the needs of transporting equipment. The net cross section of the elevator equipment shaft in Damiao iron mine is 2.3m × 3.3m

3.

9. The critical speed should be considered first; Secondly, the influence of speed rate is considered. The general rule is proportional to the 2.5th power of the cylinder diameter. The cylinder length determines the particle size characteristics of grinding materials (that is, the probability and time of medium impact), which should be determined by grinding experiments
in the actual proction, the working speed of grinding machine has a wide range. The general rule is that the rotation speed of rod mill is about 10% lower than that of ball mill of the same specification, and in ball mill, the rotation speed of small diameter ball mill is higher than that of large diameter ball mill; The working speed of the mill used for roughing is higher than that of the fine mill. At the same time, the proctivity, energy consumption and steel consumption of the mill should be taken into account when determining the optimal speed of the mill. The practice shows that the best rotation rate is 76% ～ 88% in order to improve the proctivity per unit volume; In order to save energy and steel consumption, the best speed rate should be 65% - 76%. Moreover, the proctivity of unit energy consumption can be improved by appropriately recing the rotating speed
relationship between filling rate and rotation rate: the higher the filling rate of ball mill, the higher the rotation rate needed to reach the maximum useful power. With the increase of rotation rate to a certain extent, the steel ball will change from dropping to dropping, but the transition point varies with the filling rate. The higher the filling rate is, the higher the rotation rate is.

10. 3、 The lamp room should be well ventilated; No fireworks are allowed in the lamp room and warehouse, and fire-fighting equipment should be provided
4. In the safety light room, there should be a separate room and exit for installing lamp oil and sending and receiving lamps; The gasoline storage capacity in the lamp oil loading room shall not exceed 40 liters and shall be properly kept< Article 393 special instruments must be used for preparation and filling of electro-hydraulic system. The staff must wear protective glasses, masks, rubber gloves, Rubber Aprons and rubber shoes
for storage and blending of electric fluid, it is necessary to use porcelain, glass or other containers without chemical change of electric fluid. When mixing acid electrohydraulic, only sulfuric acid should be poured into water, and it is forbidden to pour water into sulfuric acid
the room must be equipped with a solution for neutralizing the electro-hydraulic system in case of electro-hydraulic cauterization
Article 394 telephones should be installed at the bottom of the well, transportation dispatching room, main electromechanical chambers, health stations and mining areas. Underground main pump room, substation and ground fan room telephone, to have direct contact with the ground central exchange or control room
Article 395 underground telephone lines are prohibited to use the earth as a loop. The transport signal device can be powered by motor frame line or lighting line. The motor frame line can be used for high frequency communication< Article 396 electrical signals must meet the following requirements:
1. Electrical signals in mines should be able to emit sound and light at the same time. The types and uses of signals should be revealed near important signal devices
2. The signal devices of lifting personnel and main wellhead winches shall be powered by special lines
thirdly, between the water gun driver and the coal pump driver, the high-pressure pump driver and the dehydration screen driver, the signal and telephone with both sound and light should be installed< Section 6 protective grounding Article 397 the metal enclosure of electrical equipment, which may have dangerous voltage e to insulation damage, must be grounded
all equipment that must be grounded (including the shell of armored cable, lead sheath and grounding core wire of rubber cable) and local grounding device shall be connected with the main grounding grid
the grounding core of rubber cable shall not be used for other purposes
for the protective grounding of electrical equipment, the staff on ty shall conct a surface inspection once per shift
the underground grounding protection work shall be carried out in accordance with the detailed rules for installation, inspection and measurement of mine grounding protection device< Article 398 regulations on installation site of grounding electrode:
1. When there are several levels in the mine, the main grounding grid of each level shall be connected with the main grounding device. The main grounding electrode shall be embedded in the sump, and one for each sump. The main grounding electrode shall be made of steel plate with an area of not less than 0.75 square meters and a thickness of not less than 5 mm, on which a section of flat steel shall be welded to connect the lead wire< Second, the local grounding electrode can be set in the tunnel ditch or other wet places. For the grounding electrode set in the tunnel ditch, steel plates with an area of not less than 0.6 square meters and a thickness of not less than 3 mm or steel pipes with the same effective area shall be placed horizontally in the depth of the ditch; For the grounding electrode set in other places, iron pipes with a diameter of not less than 35 mm and a length of not less than 1.5 m can be used. At least 20 through holes with a diameter of not less than 5 mm shall be drilled on the pipes and buried vertically in the ground< 3. If the cable laid in the borehole cannot be connected with the general grounding grid of the mine, the general grounding electrode of this part should be set on the ground< Article 399 locations where local grounding electrodes are required:
1. Each chamber with fixed electrical equipment and separate high voltage switchgear
2. Distribution points of substation and working face in mining area< 3. Connect each junction box of power armored cable. The junction box of fixed lighting equipment in the roadway can be grounded on the spot every 100 meters or so
the 400th lead section for connection between main grounding electrode and main grounding grid shall be copper wire of no less than 50 square mm or flat steel or galvanized iron wire of no less than 100 square mm
copper wire of no less than 25 square mm or flat steel or galvanized iron wire of no less than 50 square mm shall be used for the connection between the shell of electrical equipment and the general grounding grid or local grounding, and for the connection between the armor and lead skin of the cables at both ends of the cable junction box
the transition resistance of 401 general grounding grid shall not exceed 2 ohm from the main grounding electrode to the farthest local grounding device
the resistance of grounding wire between each mobile electrical equipment and the main grounding grid or local grounding shall not exceed 1 ohm< Section 7 inspection and maintenance article 402 inspection, maintenance, repair and adjustment of electrical equipment shall only be carried out by dedicated or temporarily appointed electrical maintenance workers. For electrical equipment with voltage over 700 V, a work ticket is required for the above work
under special circumstances, electric fitter in mining area is allowed to switch on or off the electrical equipment with voltage over 700 V in the substation, but shall not open the electrical equipment for repair without authorization; The shutdown and power supply of important lines and important workplaces must be carried out by designated personnel with work tickets
Article 403 the electrical equipment whose explosion-proof performance is damaged shall be repaired in accordance with the detailed rules of this regulation "repair regulation for enclosure of explosion-proof electrical equipment in coal mines". After repair, it can only be used after being accepted by inspectors
Article 404 the following main inspection system shall be established for each mine, and the inspection results shall be recorded in a special record book. Problems found in the inspection shall be handled by a special person designated by the person in charge of the mechanical and Electrical Department of the mine.