Xinye Copper Mine Mining and Retaining House Pillar Method

The Xinyeshan Mine in Xinye is a contact-deposited skarn-type copper- tungsten deposit. There are 4 ore bodies, and the 520 and 420 ore bodies are currently used for mining. The 520 ore body is 880m long; the thickness is 2-20m, with an average of 5m; the inclination angle is 30°~90°, and the upper and lower slopes are steep, with an average of 40°. The 420 ore body is 800m long; the thickness is 0.4~3m, with an average of 2m; the inclination angle is 35°~90°, with an average of 45°. The spacing between the two ore bodies is 50-60 m; the occurrence is basically the same. Upper and lower plate as marble and granodiorite, mining, rocks are stable, the overall good. The ore contains 0.662% copper, 0.377% tungsten and 14.75% sulfur. Mining is carried out by using the mining room column method. The mining funnel is only drilled at both ends of the mine and irregular columns are left in the mine. The ore is temporarily discharged to the funnel. The stage height is 50m, the length of the mine is 40-60m, the height of the top column is 2~3m, and the height of the bottom column is 5~6m.

Except for the irregular pillars in the mine and the continuous pillars (thin thin and lean sections) that are left every 200m, all the pillars need to be recycled. Return to the mining column in the back-up type immediately after mining, usually the lower stage mining room and the upper stage mining column.

The column can be fully recovered or partially recovered (or half of the half is left, or the lower part is left, or separated), depending on the ore body conditions, grade changes, roof conditions and empty area management requirements of each ore block. The decision is based on the principle of reasonable resource recovery and security. When the thickness and inclination angle are different, the specific mining methods are different: (1) When the inclination angle is less than 40°, the ore ore is taken out from the bottom up (Fig. 1a). Horizontal or slightly inclined blasthole collapses on the heap of the mine or empty area. The ore is discharged from the ore bin of the original mine. Most of the mine's columns are harvested in this way. (2) Thin ore bodies with inclination angles greater than 40° and thicknesses of 2 to 3 m are extracted from top to bottom synchronously with large quantities of mines. Because the sidewalks are not safe enough, this method can only be partially recovered. (3) When the inclination angle is greater than 40° and the thickness is greater than 5m, the medium-deep hole is used for recovery (Fig. 1b). The rock drilling chamber is expanded by means of a communication channel. After the mine is released, the pillars can be collapsed. According to the condition of the roof, one column can be blasted separately or once.

When the roadway in the upper stage does not need to be retained, the top column is produced with the mine house, and vice versa. When the dip angle of the ore body is slow, the shallow hole is used for recovery, and when it is steep and thick, the horizontal fan-shaped medium-deep hole is used for recovery.

Figure 1 Xinye copper mine column mining

A—shallow hole blasting mining column; b—medium-deep hole mining column;

1—Uphill; 2—Contact Road; 3—Intercolum; 4—Electricity; 5—Funnel;

6—Transportation roadway; 7—gun hole; 8—fan-shaped deep hole; 9—rock drilling chamber

There are two ways to recover the bottom column. One is to combine with the top column of the corresponding mine in the lower part, and the other is to withdraw from the transport roadway (Fig. 2), with 8~10m as a retreat step; The roadway is expanded to the surrounding rock of the upper and lower plates; the horizontal shallow holes are gradually taken to the upper part to pull the bottom layer. A series of three types of mining methods are adopted; when the roof of the empty area is stable, it is loaded and loaded by the rock loader; if possible, the electric power is used to the lower empty field, or the chute; when the roof is not in good condition, the electric pick and the rock loader are used. Combined loading.

Figure 2 Xinye Copper Mine Bottom Column Mining

1—horizontal blasthole; 2—bottom column; 3—transport lane; 4—loading machine;

5—Ore heap; 6—Expanding the blasthole; 7—Upper mountain pass; 8-Drain

The above method is used to recover and obtain better results. By 1983, the ore recovery rate of the pillars was 84.83%, which was 16.68% higher than the actual recovery rate of the pillars in the upper stage (68.16%), the recovery rate of the ore column and the top column was 89%, and the recovery rate of the bottom column ore was up to 78.15%.