Filling material used for mining remained gateway along goafs

Abstract

The invention discloses a filling material used for a mining remained gateway along goafs. The filling material comprises 35-55% of coal ash, 5-25% of quicklime powder, 5-20% of ground slag powder, 2-20% of silicate cement, 20-40% of red mud, 0.35-5.5% of an early strength component, 0.015-0.035% of a water reducing agent, and 0.0045-0.009% of an expansive compound. Using processes of the filling material at a pit bottom are simple. The filling material is added with water, stirred and conveyed by a single pipe. After addition of the water and stirring, workability of the slurry is good, the slump of the slurry after the slurry is allowed to stand in the pipe for 2 h is barely changed. During emergency situations, pipe blocking due to long standing time of the slurry in the pipe is not generated. By addition of the expansive component, a certain volume expansion is generated with curing of the material, the increasing speed of the strength is high, a roof can be effectively supported in time, and the filling quality is high.

Description

technical field [0001] The invention relates to a filling material used in underground coal mines, in particular to a mine-used filling material for gob-side entry retention. Background technique [0002] In order to recover the security coal pillars left in the traditional mining method, certain technical means are used to re-support the tunnel in the previous section for the use of the next section. This method of retaining roadways is along the edge of the goaf Retaining at the original trough position is called gob-side entry retention, which can maximize the recovery of resources and avoid coal loss. At present, the commonly used filling methods for gob-side entry retention at home and abroad mainly include cement-based paste filling, gangue belt filling, high-water quick-setting material filling and so on. Due to the gob-side entry retention under the condition of a hard roof, the working face basically has a long time to hang from the top and a large distance from th...

AI Technical Summary

Problems solved by technology

Due to the gob-side entry retention under the condition of a hard roof, the working face basically has a long time to hang from the top and a large distance from the top, the defects of the above three filling methods are: the filling body next to the road will bear a large roof pressure, and for cement The base paste filling body has low initial strength and poor shrinkability, and cannot well adapt to the movement of hard rock formations; the filling workload of the gangue belt is large, and the support resistance provided by the gangue belt is small, and the support effect is poor; The cost of high-water quick-setting materials is high, the support strength is low, and it is not suitable for the high-pressure mutation of the gob-side roadway. During the secondary mining of the working face, the filling body is easily deformed and damaged, resulting in serious air leakage in the gob. and the maintenance of the roadway has brought great difficulties

[0003] Chinese patent CN101143772A discloses a filling material for gob-side entry retention, which is composed of cement, fly ash, gravel, sand, water, water reducing agent, water retaining agent, air-entraining agent and early strength agent, and has the following disadvantages : The strength of the material rises relatively slowly, and cannot effectively support the roof in time; the workability of the slurry is relatively poor, and the pipeline will be blocked in the event of an emergency. Secondly, the roadside filling material must use a special concrete pump For pumping, the price of the pump is relatively high, which increases the investment cost

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