31results about How to "Reduce the rate of penetration" patented technology

The invention discloses a method for coal mining to the greatly oblique coal layer, comprising two steps: designing the method and back producing technique, placing slit flexible shielding support in the coal layer of 8-10m and deciding return airway and cutting point; the back producing technique includes enlarging airway, installing support, put down support and desinence of working face, etc. The method has simple operational steps as well as remarkable economic benefit.

The invention provides a mining method for a long wall working face of an ultra thick seam, and belongs to the technical field of coal resource mining. The method comprises the steps that firstly, the ultra thick seam is divided into a top layer, a middle layer and a bottom layer; then mining is carried out on the top layer by adopting a comprehensive mechanized coal mining method, and a top screen monitoring system, a displacement monitoring system and a pressure monitoring system are arranged on a goaf bottom plate of the top layer synchronously in a paved mode; after the mining carried out on the top layer is finished, the migration condition of a top plate of the ultra thick seam is analyzed, the mining is carried out on the bottom layer, and finally the mining is carried out on each layer from bottom to top gradually until complete mining is carried out on the ultra thick seam. According to the method, a laneway arrangement system is simple, the refuse rate of raw coal is low, the economic benefit is obvious, and it is achieved that safe, efficient and reliable mining can be carried out on the ultra thick seam with the thickness which reaches above 20 m.

The invention discloses a gob-side entry support method for a small-area thin coal seam blast mining face. The small-area thin coal seam blast mining face is supported by an I-shaped steel shed and wood, and a single hydraulic prop is used. To strengthen the support, the support method adopts the following steps: (1) Advance support: add bolts on the advance blast mining face in the trough; erect the I-shaped steel shed on the advance blast mining face; (2) lag support Protection: After the erection of the I-shaped steel shed is completed, a single hydraulic prop is erected to strengthen the support at the lagging blast mining face; Just carry out charging and put the top when falling. The present invention uses the I-shaped steel shed, the single pillar, and the top of the charge to carry out the alley retention. The gobside entry retaining has low investment, quick effect, high benefit and high safety factor, and is one of the extremely beneficial ways to enhance mine safety production.

The invention relates to a mining method for mining an inclined manganese mineralization bed in an ore body through a mobile shield support. The method comprises the following steps: exploring the orebody, tunneling a return airway and a transportation roadway as well as a mining roadway communicated with the transportation roadway in the ore body, arranging a shield support in the mining roadway, forming a working space and a mobile shield support in the shield support, enabling the working space to move along a stope face, mining manganese ore in the working space, and transporting the orevia the transportation roadway. With the adoption of the technical scheme in the invention, only the return airway, the transportation roadway and the mining roadway need to be tunneled, the mining operating process is simplified, the drifting operating time is saved, and the labor efficiency is improved. Therefore, fresh air can continuously flow into the mining roadway via the return airway or the transportation roadway, and the operating environment and operating safety in the return airway are ensured, so that continuous mining operations can be ensured due to the mining operation of the inclined manganese mineralization bed, the mining operation efficiency is improved, the shield support can be repeatedly used, and the supporting raw materials are saved.

The invention provides a method for mining coal from a heavy pitch thick coal seam in a horizontal and segmental short wall manner. The method comprises the following steps of: supporting and caving coal by using a top coal caving hydraulic support in a work surface; drilling holes, blasting coal, and conveying the coal with a scraper conveyor; performing gob-side entry retaining by using a prefabricated metal shed or a plastic bucket. The coal-mining method can realize mechanical mining of the heavy pitch thick coal seam, greatly improves yield and efficiency of the working face and ensures safe production.

The invention provides a coal mining method for pre-mining layered broken top coal in the middle of an extra-thick coal seam, belonging to the field of coal mining. The method includes firstly arranging a longwall working face in the middle of the coal seam for pre-mining a 3-7m coal seam, then the coal body in the upper part of the coal seam is fully broken under the action of mine pressure and gravity, and the broken coal body falls on the unmined coal body in the lower part of the coal seam; In the future, reserve 2-3m top-coal at the lower part of the coal seam to arrange fully-mechanized caving working face for top-coal caving mining. The height of coal cutting is generally 3-5m, and the reserved 2-3m top-coal and broken caving The coal body in the upper part of the coal seam is released at the coal outlet of the hydraulic support of the fully mechanized caving face at the lower part of the coal seam, and is transported out of the working face by the conveyor behind the support. The thickness of the coal seam can reach 40m at one time. The method of the invention gives full play to the advantages of fully mechanized mining and fully mechanized caving mining, has the advantages of less layering, low roadway excavation rate, high recovery rate, and less times of moving and reversing the working face, and has important guidance for safe and efficient mining of extra-thick coal seams significance.

The invention discloses a concrete modular gob-side roadway support structure for mining without coal pillars, which belongs to the technical field of mineral resource mining; on the basis of the technology of flexible mold concrete gob-side roadway retention, a concrete modular gobside roadway for mining without coal pillars is proposed. Empty roadway support structure, the concrete modular wall consists of three parts: the upper roof unloading module, the middle wall layer module, and the lower foundation module, wherein the roof unloading module includes the roofing intermediate concrete module and the roofing concrete module 1. A concrete module connected to the roof gap, the top surface of the wall layer module is provided with a plurality of strip-shaped semicircular protrusions and semicircular grooves to prevent the module from sliding; The number of excavated roadways reduces the cost of roadway maintenance, and the modular concrete can be recycled and reused, which greatly reduces the support production cost.