The section mining method is based on the division stage, and then the stage is divided into sections, each of which forms an independent mining and ventilation system. During the continuous mining, the temporary top and bottom columns are reserved between the sections, or only the temporary bottom column (or the top column) is retained, so as to be divided into strip-shaped mine houses and pillars along the inclined direction of the ore body, and the first mining room, and at the same time Back to the mining column, but the former maintains a certain distance from the latter. In the case of discontinuous mining, the temporary column is left at a certain distance in the section, and it is divided into several mining units (mines), first mining room, and then mining the inter-column and top column adjacent to the mining room, and at the same time Handling gobs.

Second, the applicable conditions

One of the important features of this law is that it can effectively control the exposed area of ​​the roof when recovering by relying on reasonable selection of the section height and the structural parameters of the temporary pillar, so it can be used to mine ore and surrounding rock in moderately stable ore bodies. Since each segment has an independent ore-mining system, different ore structures can be used to solve the ore transportation according to different inclination angles of the ore body, and the inclination range of the ore body can be wide, from gentle inclination to steep inclination. However, the mining and cutting engineering of this method is very large. Mainly used for mining ore bodies above medium thickness.

When in recent years, in our ferrous metals, non-ferrous metals and chemical mining gently inclined inclined thick ore body above, the Act gained more use and development.

Third, the structure parameters of the ore block

Stage height and segment height. The main factor affecting the height of the stage is the inclination of the ore body. Mining gently inclined ore bodies, generally take about 30m; mining inclined, steeply inclined ore bodies, generally take 50m.

A reasonable drilling depth for the rig must be considered when determining the segment height. When using a medium-deep hole to mine, the height of the segment is generally 8 to 10 m; when the deep hole is falling, the height of the segment may be 20 to 25 m. However, the depth of drilling and the location of the rock-boring roadway are closely related. Therefore, the two must be considered together. If the explosive force is used, the length of the section should be controlled at 20~30m; the surrounding rock is not stable enough. The allowable exposed area of ​​the top plate is the most important factor in determining the segment height.

When non-continuous mining is adopted, the mining room is generally arranged along the strike, and its length mainly depends on the pressure of the mining site and the stability of the surrounding rock, generally about 30-40 m.

Fourth, the mining cutting work

There are two kinds of layouts in the section roadway: intrapulmonary and extrapulse. Although the external layout is larger, the mining cost is higher, but the mining cost is higher, but it is beneficial to the mining column; the amount of ore in the bottom column The proportion is small; the section roadway can be connected by ramps, which is beneficial to the transfer of equipment and the transportation of materials, so it is widely used in production.

Between the stage transportation lane and each section roadway, when transported by the scraper, the slope is connected with a slope of 10% to 20%; when transported by the loader or electric raft, the patio is connected and installed electric or Wind winches to lift equipment, tools and materials.

The ore is transported out of the mining face and is often transported to the transport lane. The spacing of the chute determines the transport equipment used. When transported by a scraper, it is generally 100 to 150 m; when it is transported by electric power, it usually does not exceed 50 m. In the case of mining gently inclined ore bodies, in order to reduce the amount of mining work, in the case of small production, electric rafts can be used.

The forming method and the steps of the cutting groove are: firstly, cutting the cutting patio and the cutting lane on one side of the segmented roadway and the side of the pillar adjacent to the mining room, and then playing parallel deep holes or fan-shaped deep holes in the cutting lane or The annular deep hole is blasted in sequence.

The bottom structure of the method can be divided into a bottom structure and a bottomless structure. There are usually two types of bottom structures, one is the bottom structure of the electric raft: it is composed of a common funnel or a gutter powering ramp, and the ore is transported by electricity; the other is the bottom structure of the loader and the scraper: It consists of a common funnel or gutter plus a loading lane, and the ore is transported by a loader and scraper. The bottomless structure is to transport the ore directly in the segmented vein (along) roadway with a loader or scraper.

Fifth, mining work

At present, China is widely used in rock drilling rigs, with YG-80, YG-90, YG-40 and BBC-120F rock drills to drill upward fan-shaped deep holes. Production practice proves that when the gantry is used for inclined roadway (uphill), it is very difficult to erect and fix, and it is difficult to guarantee the construction quality. Recently, Wang set of phosphorus ore and Tianshui Pneumatic Tool Factory jointly developed FJY-25B-type drilling stand, greatly improves the above-mentioned conditions. The gantry has the following characteristics: (1) The work can be kept stable under the condition of strong vibration, and the rock does not slide in the patio with the inclination angle greater than 30°, which greatly improves the construction quality of the blasthole. (2) The operation platform was changed from the original fixed type to the lifting type, so that the table top can maintain the horizontal state under any circumstances, and the rock drilling working conditions are improved. The use of the FHI/24 pneumatic winch to pull the movement of the rock drilling equipment reduces the labor intensity. Mining rigs with scalloped deep holes or annular deep holes are widely used in foreign mines.

The ore that has collapsed, domestic mines are currently transported by loaders or electric picks. Scrapers are widely used in foreign mines.

The roof management of the section mining method is particularly important when mining ore bodies that are not stable enough. It seriously affects the safety of operations and the loss and depletion of ore.

Correctly selecting the structural parameters of the nuggets and reasonably retaining the pillars so that the upper plate does not cause chipping or slumping during the recovery process is the main technical measure in roof management.

When the surrounding rock is relatively stable, a high-segment section of 15 m or more and a continuous recovery scheme of retaining only the item (bottom) column in the section may be adopted, and the pillar is subsequently recovered as the mining work of the mine is advanced. But you must maintain a certain distance. Under such conditions, in order to deal with the goaf, it is sometimes necessary to make holes in the surrounding rock of the upper plate to force the top.

If the surrounding rock is not stable enough, a low-segment mining recovery plan is often used. The height of the segment is 8 to 10 m, and a column of 5 to 6 m width and a column of 3 to 5 m are left in the ore block. The mining room is first used, the top column and the column are recovered, and the goaf is processed.

Sixth, evaluation

The main advantages of this mining method are: the stability of the ore and surrounding rock and the adaptability of the inclination of the ore body are stronger than other empty field methods, the scope of use is wide, and the flexibility is large; at the same time, there are many working faces for recovery, usually in a mine. There are 2 to 3 sections in the section for simultaneous recovery, the operation is concentrated, and the mining intensity is large. The mines that are transported by scrapers abroad can have an average production capacity of 20,000 tons/month, and the output of the mine section can reach 4.5 to 60,000 tons / month; easy to use trackless equipment, is conducive to achieve high mechanization; can flexibly adjust the structural parameters of the ore block according to the stability of the surrounding rock; workers in the small section of the roadway to carry out mining operations, security conditions Good; retained temporary pillars can be recycled in time; labor productivity is high, labor consumption is small, and costs are low. The main disadvantage of this law is that since each section generally needs to be arranged with more roadway engineering, it is necessary to arrange the slope road when transporting with the scraper. Many of the projects are often arranged outside the vein, and the cutting is adopted. The amount of engineering is large and the cost is high. When the ore body with insufficient surrounding rock is mined, the ore-mining conditions are poor, and the loss and depletion of the ore are sometimes very large.

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