Mining of the wall-filling mining method

(1) Caving ore and surrounding rock. The wall-filling mining method requires that the ore and surrounding rock fall apart in stages, and the order of the collapsed ore depends on the dip angle of the vein and the stability of the ore. When mining steeply inclined veins, the ore is generally collapsed first, and when the surrounding rock stability conditions are poor, the surrounding rock should be collapsed first; when the gently diverted veins are mined, the surrounding rock is first collapsed. When the ore stability is poor, the roof surrounding rock should be collapsed. When the mine is first falling, because the vein is too thin and sandwiched, it is advisable to use a small diameter drill head to drill shallow holes with a depth of not more than 1.0 to 1.5 m, the hole spacing is 0.4 to 0.6 m, and blasting with a space charge is used to reduce Destruction of the surrounding rock. When the surrounding rock is first collapsed, the ore-falling parameters may be appropriately increased. The amount of collapse of the surrounding rock must meet the requirements of the minimum recovery space. The minimum size of the mining yard width of the mining steeply inclined ore body is: moving the ore by manual, electric or unicycle When the ore is transported by CT-500HE electric scraper, it is not less than 1.1~1.2m. When mining gently inclined veins, the height of the mining frame is not less than 1.8~2.0m. When determining the amount of rock mass in the caving, it should also meet the requirements of filling the goaf, and strive not to take the filling material or release the excess waste rock.

(2) Ore transport. The caving ore can be transported to the ore chute manually or mechanically in the stope. When the ore is manually transported, the working condition is poor, the labor intensity is high, and the efficiency is low. In order to realize mechanization of narrow working face ore transportation, the ore has been successfully transported using 5.5kw small electric shovel and CT-500HE small electric scraper. When mining gently inclined veins, electric picks are often used.

(3) Laying the cushion. In order to avoid the high-grade pieces of ore or fines mixed into the filling, a cushion must be laid on the filling surface. The cushion material may be wood, iron plate, tapes, concrete mortar, or the like. Practice has shown that wood or iron plates are easily broken or deformed when they break down ore, resulting in a large loss of fine ore. When laying the cushion with semi-old tape, in order to prevent the tape from being damaged during blasting, a cushioning material such as a straw bag should be laid under the tape. In order to recover the powder ore that has been leaked from the tape joint, a layer of canvas should be laid between the tape and the straw layer. The concrete paving thickness is 0.1-0.15m, and the strength is up to 3MPa to meet the requirements of falling mine and mechanical transportation. Practice has shown that the concrete cushion is conducive to mechanized transport and also maximizes the recovery of fines.

(4) Set up a well. The smooth walks and the smooth ore runways in the stope will continue to rise as the stratification advances. Downstream patios are usually arranged in double spaces for pedestrians and transport. In order to create conditions for the mining, the paved patio should be stratified a certain distance ahead of time, and more wooden erection should be used, but the side of the filling body should be separated by dense wooden boards. In order to save the wood material patio, the cylinder surrounded by the steel plate can be heightened step by step, and the pedestrian ladder is welded in the cylinder. The down-flow ore chute is best erected with an inverted conical cylinder surrounded by a 3mm thick steel plate, each section having a height of 0.5 to 1.0 m and a diameter of 0.6 to 0.8 m. The down-flow ore chute can also be erected with wood. In order to prevent the loss of fine ore, a layer of close-fitting wood must be nailed on the inside of the chute.

(5) Filling. When mining steeply inclined veins, the filling material is transported by hand, electric shovel or scraper, and the filling surface is filled.

When mining gently inclined veins, the filling work is a heavy physical labor. With the excavation of the working face, a stone wall is built with a large piece of waste rock that has fallen down every 1.5 to 2.0 m, so that it has a good The pressure bearing performance and the failure to be knocked down during blasting shall be such that the angle between the wall and the horizontal plane is between 70° and 80°, and the stone walls are filled with gravel. The stone wall and the waste rock should be tightly connected. When the local veins are thicker and the surrounding rock volume is not enough, the interval filling can also be used. In order to increase the stability of the filling body, some retaining walls made of reinforced concrete prefabricated parts should be erected at appropriate positions.