Mining, cutting, and mining work for natural caving

Mining block mining work:

Basically similar to the subdivision method.

(1) Stage transportation lane layout – the original ore body is transported by pulse; the extremely thick ore body is mined and transported by pulse inside and outside.

(2) Bottom structure form – using the electric bottom structure.

(3) Other mining lanes—such as electric ramps, mines, pedestrian wells, rock drilling patios, and rock drilling chambers—are similar to the sublevel caving method described above.

Cutting work:

(1) Cutting work includes pulling down the roadway, cutting the patio, leaking, cutting the roadway, etc.

(2) The method and requirements for the excavation of the compensation space of the stage caving method.

The size of the compensation space required for the stage caving method shall be determined according to the amount of ore that is simultaneously collapsed at the top. The compensation factor usually used is 20 to 30%. When crushing and blasting is used to stabilize the ore, 15-20% can be used.

(3) The distribution of the compensation space should be compatible with the range of deep hole control. If the area of ​​the cut exceeds the allowable exposed area of ​​the ore, the temporary column can be left. In this temporary pillar, the tunnel is excavated in advance, and the deep hole is drilled. The temporary pillar and the ore block are blasted at the same time.

Temporary pillars can be arranged along the strike and sometimes cut along the strike. The safety of the layout work along the strike is small. The width of the temporary pillar is generally 3 to 5 meters. That is, C = 3 to 5 meters. A temporary pillar (mine type) of 2.0 m should be left on the side in contact with the collapsed surrounding rock. It does not require special blasting, and it is naturally brought back as it is harvested. (ie a = 2.0 meters)

Mining work:

The mining method can be divided into horizontal deep hole (medium deep hole) ore and vertical layer falling ore. The former is more versatile. (Shallow hole and drug room drop are used less)

The mining work includes: mining bottom, deep rock drilling, charge blasting, ventilation and mining.

In order to speed up the recovery of the ore block, deep hole drilling and excavation compensation diverticulum work can be carried out at the same time, generally requiring two jobs to be completed at the same time. When the compensation chamber is heavily discharged, the full-stage ore blasting can be started. Then a lot of ore is carried out.

After the large blasting, the upper cover rock layer can be collapsed under normal conditions, and the goaf can be filled with the ore. When some surrounding rocks are relatively stable and cannot be naturally collapsed, the project of caving surrounding rock must be planned before the mining. When the mine collapses, the surrounding rock is forced to collapse to form a covering layer.

In order to ensure the safety of the mining work, at least the upper part of the recovery stage should have a loose rock cushion of 30-40 meters thick. (In fact, some mine mats are 30 to 100 meters thick).

Die Casting is a Metal Casting process that is characterized by forcing molten metal under high pressure into a mold cavity. The mold cavity is created using two hardened tool steel dies which have been machined into shape and work similarly to an injection mold during the process. Most die castings are made from non-ferrous metals, specifically zinc, copper, aluminum, magnesium, lead, pewter and tin-based alloys. Depending on the type of metal being cast, a hot- or cold-chamber machine is used.