(1) Overview:

(1) This bottom structure, underground metal mines in our country which is widely used. It is suitable for mining medium thick and thick ore bodies.

(2) Features——1 The ore mined is subjected to the mine roadway from the vertical sluice to the electric shovel. Then the electric shovel is used to carry the ore into the mine-boring well and into the mine car of the transport lane through the funnel gate.

2 The large ore that has slipped down from the mining roadway is secondarily crushed in the electric roadway (and thus called the secondary broken roadway).

(3) Classification of the bottom structure of the ore transporting ore - can be divided into three categories: 1 funnel type; 2 sulcus type; 3 flat bottom type;

( 2) Funnel electric bottom structure

(1) Applicable conditions: It is applicable to various ore conditions and is widely used.

(2) Advantages: the amount of cutting on the bottom is small, and the stability of the bottom column is better.

(3) Funnel structure and its size.

C = (2.5 ~ 3.5) qualified block rate (for example, qualified block rate = 600mm, C = 1.5 ~ 1.8 meters) b = 1.5 ~ 2.0M,

a=(1/2~2/3)B,

B——Electric ramp width

D——effective ore section

1 The area of ​​the mining area responsible for each funnel:

Under normal circumstances, each funnel has a mining area of ​​30 to 50 m ² and a maximum of more than 50 m ² .

2 height of the bottom column: 8 to 15 meters

a) from the transport level to the (floor) power consumption floor floor height of 3 to 16 meters;

b) 5 to 9 meters from the bottom of the electric ramp to the horizontal bottom of the bottom;

3 funnel spacing: generally 5 to 7 meters;

4 The distance between the center line of the electric ramp and the center line of the funnel neck is 3.5 to 4.0 meters;

5 funnel slope angle is generally 45 ° ~ 55 °;

6 It is required that the relative positional relationship between the funnel neck and the electric raft is designed to be a natural slope formed by the falling ore, which can occupy 1/2 to 2/3 of the width of the electric tunnel. That is, a = (1/2 ~ 2 / 3) B, which is advantageous for the wide tapping of the electric ramp.

7 Funnel neck width C = (2.5 ~ 3.0) qualified block.

8 Funnel neck height - Depending on the stability of the ore, the height of the funnel neck should be minimized if the stability requirements are met. Generally 1.5 to 2.0 meters

9 Funnel shape - square and round. For a self-reproducing mine, what shape is the funnel, and slip has no essential effect.

10 The bottom column accounts for 16-20% of the total ore.

Determination of the size of the funnel neck: It is mainly determined according to the ore block size determined by each mine. The medium and small ore is generally about 400mm; the large ore is generally about 400mm, depending on the size of the mine car.

Practice has proved that there are three ores that block the funnel neck more likely, and the possibility of blocking four ores is relatively small. This gives a C = (2.5 ~ 3.0) acceptable block.

Mine management personnel should always measure the ore blockiness. Check if the ore blockiness is satisfactory. In order to reduce the clogging of the funnel, some mines have a half-neck section of 2.5 x 2 or 2.5 x 2.5 m2. It is generally 1.8 x 1.8 or 2 x 2 m2.

(4) Arrangement of the funnel (two types)

1) Symmetrical arrangement

When the raft is supported by wood or metal brackets, the symmetrical arrangement is beneficial to the bismuth ore, and the hoe can be straight and smooth, and the support is less difficult.

2) Staggered arrangement - This arrangement allows the funnel to be evenly arranged, with a small amount of ore remaining in the upper portion of the funnel ridge, which is beneficial for the recovery of ore. The stability of the stability of the bottom column is relatively small. Better security (2 people)

In addition, since the funnels are staggered on the electric ramp, the height of the pile is low, which is convenient for the bucket to operate, and the failure of the mine to block the ramp is not easy to occur. Therefore, staggered arrangement is generally adopted in production.

However, when using ramp support, it is not advisable to use staggered arrangements. Because the support of the ramp and the Dokcheon mouth is difficult, and the piles staggered in the ramps make the electric raft run into a curve, it is easy to pull the bracket down.