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Filling mining method, mining and filling the top pillar of the mine
Figure 1 shows the case where the top and bottom columns are recovered by the downward stratified filling method when the ore is not stable. Layering can be achieved by parallel or fan-shaped approaches. When the stratification above the recovery level, the ore is transported out through the transport lane; the ore below the transport level can be released through the chute in the pillar or the ore-draining well extending upward in the original mine.
Figure 1 Downward stratified filling mining method mining top and bottom column
1--distribution slide; 2-Pedestrian patio; 3-layered cutting lane; 4-recovery approach
In actual production, as long as the ore stability is allowed, the upward stratified filling method is still used. According to mine practice, the following experiences are worth learning:
   First, there are several ways to keep the pillars in the stage without continuous mining or mining.
(1) continuous mining in the upper and lower stages, without leaving the top and bottom columns between the two stages;
(2) With the mining on the mining room, the top column or the top bottom column will be collected together;
(3) The upper stage adopts the concrete artificial bottom column, and the top column is finished with the mining room, and the empty area formed by the top column mining is filled from the roadway of the artificial bottom column.
FIG 2 is an example where the opening lead zinc ore mine roof pillar when horizontal slice to spend cemented filling mining method, ore loss rate is still high (loss rate statistics two stope average of 30.8%), and The progress of the mining is slow, so that the recovery of the upper stage can not be completed, and the number of operating phases increases year by year, which directly affects the management and productivity of the mine systems. In this regard, the following measures have been taken: 1 If the geological conditions and the development of the mining system permit, the mining site at the current stage will be continuously mined with the upper stage, leaving the top column of the stope at this stage and the bottom column of the upper stage. If the concrete artificial bottom structure is to be constructed in the upper stage of the continuous mining, the artificial bottom column can be poured into the lower stage after the mining of the lower stage to the upper stage of the upper stage and filled to the upper stage level. According to statistics, the eight concrete artificial slabs constructed in the previous stage using this method have a 1.1% reduction in ore loss rate and a depletion rate of 18.06%. 2 Firstly, the bottom column and the bottom layer of ore are taken back, and a concrete artificial bottom column of 4 to 6 m height is constructed. According to the output of 24 individual workers and the bottom, the loss rate is 3.3% and the depletion rate is 18.4%.
Figure 2 Fankou lead-zinc mine continuous mining top and bottom column
1- artificial false alley; 2-concrete bottom column; 3-column; 4-clip stone; 5--stage bottom column
Fig. 3 shows the recovery of the top column by the filling method when there is a concrete bottom column. At this time, the top column mining is completed under the protection of the artificial bottom column as the top mining process of the lower stop. According to the strength of the artificial bottom column, it can be filled with a strip top or a top fill. Some stope Jinchuan nickel recovery was roof top column access this method, strength of the concrete pillar which R 28 = 5 ~ 7.5MPa, the exposed area of 100 ~ 150m 2, and filling in mining months, artificial pillar Without obvious deformation and damage, the top column can be completely harvested. The disadvantage is that the self-flow filling of the concrete is not good enough, and the distance between the top plate and the filling material is still about 0.5-1.0 m.
Figure 3 Striped top filling back to the top column
A- top column before mining; b-top column recovery; 1 - artificial concrete roadway; 2 - top column;
3-Shunlu Patio; 4-mining chute; 5-un-mined column; 6-reserved patio; 7-mine heap; 8-rubber filling
The top and bottom columns are connected with the lower mine. If some roadways need to be retained in the upper stage, concrete artificial roadways should be constructed in the filling body according to the required parts.
   2. According to the stability of each layered ore, the number and location of the roadway, the stratified area, etc., different charging and recycling operations are adopted.
Such as: layered one-time filling, partition top filling, inlet top filling and so on. The general rule is that the closer to the bottom of the upper stop, the smaller the unfilled space and the shorter the time.
   Third, strengthen ground pressure management and roof maintenance
The strength and quality of the concrete filling body of the artificial floor or the upper stage mine shall meet the requirements of the top and bottom column recovery. When the upper part is non-cemented and there is no concrete cushion, safety should be paid attention to. The 1.5~2.0m thick top cover should not be taken. The quality of the top filling should be ensured. If the span is too large, it can be properly left according to the condition of the roof. Point the column, or strengthen the temporary support. The use of wire rope anchors to reinforce the top and bottom columns is an effective measure. Consolidation Test copper ore Fenghuangshan PILLAR top three in the stope, using rope anchor ø24.5mm, pitch 2.5 ~ 4.5m, the burden on each of the anchor area 12 ~ 14m 2, breaking force greater than 42t. When each layer is harvested, some short anchors can be added according to the situation. Taking this measure, 343,000 tons of ore can be safely produced. The Australian Mount Isa mine was harvested by the upward stratified filling method to the upper stage 8m, and the upward drilling of the blasthole with a depth of 18m (the height of the bottom column is 12m), and then continue to use the same method to recover the top and bottom columns. The recovery rate is 95%.
Figure 4 shows that the Hongtoushan Copper Mine uses a layered partitioned strip filling method to recover the top and bottom columns. The mine is filled with tailings cement, and the horizontal column is filled with horizontal tailing filling method, but the lowermost part is filled with cement. The filling body has a measured strength of 0.9 to 4.6 MPa. The top and bottom columns are 12m high. The ore of 1~1.5m thick is left in the upper part of the bottom column. The rest is divided into three layers. The first and second floors are classified as zoned mining, and the third layer is divided into strips. Before the first layer is collected, the tailings are filled with the tailings, and the uppermost 0.5~1.0m is filled with tailings cement (strength of 2.0-3.0 MPa). The first layer is 3 m high and is divided into two partitions of approximately equal area. The ramp is excavated from the intersection of the extra-vehicle transport lane to the first layered section. After filling the mine, the mine tunnel is excavated from the lower end of the ramp. The roadway is drilled into the upper road, and the approach is the free-face retreat. After a section is taken and the roof is filled, another one is taken back. Partition. The partition between the partitions is made of a sandbag to form a partition wall. After the first layer is finished, the slope is raised and connected to the second layer by filling the lower part of the upper top. In order to avoid the safety impact of the roadway, the second layer is 5m high. Divided into 4 partitions, in order to pick up. In order to create better safety conditions, one pillar is left in each of the first and third divisions. After the topping is completed, the third layer of the ramp is connected in the same way. The third stratification adopts stripe mining, and the mining roads (2.5m high and 3m wide) are excavated in the strips, and the split pillars with a width of 2m are left between the roads. In the case of a safety permit, a fraction of the pillars can be harvested and the last filling. The method was used to get better results. The ore recovery rate was 80.02%, the depletion rate was 4.7%, and the average production capacity of the stope was 252t/d.
Figure 4 layered partition strip topping back to the top pillar
A-longitudinal section (II tier mining); b-I stratified mining; c-cross section (before tier III mining);
I, II, III-stratified number; 1-external roadway; 2-slope track; 3-slide mine; 4-cut roadway;
5-return well; 6-stage return airway; 7-partition wall; 8-safe pillar; 9-1, 2 partition number