AU2015387576B2

AU2015387576B2 - Mining chemical anchor cable anchor-unhooking apparatus and method

Info

Publication number: AU2015387576B2
Application number: AU2015387576A
Authority: AU
Inventors: Dongjiang PAN; Xiaoyong Xu; Nong Zhang; Tianchi ZHANG
Original assignee: China University of Mining and Technology CUMT
Current assignee: China University of Mining and Technology CUMT
Priority date: 2015-03-25
Filing date: 2015-12-21
Publication date: 2017-12-07
Anticipated expiration: 2035-12-21
Also published as: AU2015387576A1; CN104790989A; CN104790989B; WO2016150211A1

Abstract

A mining chemical anchor cable anchor-unhooking apparatus, applicable in anchor-unhooking operations for in tunnels, primarily comprising four parts, namely an explosive charge (2), a diversion tube (3), a specially-made anchor ring (7), and a throttle (4). An acidic solution in the explosive charge (2) is introduced via the diversion tube (3) into a gap between the specially-made anchor ring (7) and an anchor cable (1), the acidic solution corrodes and weakens the anchor cable, and a liquid waste from the reaction is discharged via a diversion hole (5) at the lower side of the specially-made anchor ring (7). Then, a lagging mining pressure is utilized to implement an anchor-unhooking effect. The rate of corrosion can be set by means of controlling the flow rate of the throttle (4) or the concentration of the acidic solution in the explosive charge (2), thus adjusting the time to failure of the anchor cable (1). The apparatus simplifies an anchor-unhooking construction technique, reduces labor intensity for workers, allows artificial control of the time to failure of anchoring, increases the safeness of an anchor-unhooking process, and is structurally simple and easy to promote. Also disclosed is a mining chemical anchor cable anchor-unhooking method.

Description

MINING CHEMICAL ANCHOR CABLE ANCHOR-UNHOOKING

APPARATUS AND METHOD

BACKGROUND

Technical Field

The present invention relates to a mining chemical anchor cable anchor-unhooking apparatus and method, especially applicable to anchor-unhooking operations in tunnels.

Related Art

The anchor bolt-cable support in a coal roadway is a support mode widely used in China, and has the advantages of simple operation, good support effect and the like, but also will cause a larger area hanging arch at the end of a working face, resulting in the accumulation of gas at the end, thus bringing great hidden dangers to a roof and gas management. Therefore, how to ensure that the roof does not collapse before the working face is pushed and the roof timely collapses after the working face is pushed is an issue that needs to be addressed. To this end, the anchor-unhooking operations are usually carried out in the coal mining operation process.

At present, the mechanical anchor unhooking is commonly adopted and mainly has the following problems that: the roof loses the anchoring force immediately after anchor unhooking, easily resulting in roof falling; the pulling by force in the anchor-unhooking process increases the risk of roof falling; the anchor-unhooking effect is poor, the efficiency is low, and the anchor cable peeling frequently occurs; and the anchor-unhooking equipment is heavier, and is not easy to operate, the cost is higher, and the use is limited. Therefore, it is urgent to provide a novel anchor-unhooking apparatus and method to solve the above problems.

SUMMARY

Technical problem: The objective of the present invention is to provide a mining chemical anchor cable anchor-unhooking apparatus and method in order to overcome the defects of the existing mechanical anchor-unhooking method, so that the time to failure of anchoring is artificially controlled by utilizing a chemical anchor cable, and thus a safe anchor-unhooking effect is achieved.

Technical scheme: The mining chemical anchor cable anchor-unhooking apparatus provided by the present invention comprises a lock and a pallet which are sleeved over the exposed section of an anchor cable, a specially-made anchor ring is arranged between the lock and the pallet, and two diversion holes which are longitudinally asymmetrical are formed in the radial direction of the specially-made anchor ring; a diversion tube is arranged in the diversion hole at the upper part, and is connected with an explosive charge arranged on a roof, and the explosive charge contains a mixed acidic solution having a concentration of 5 to 12 mol / L; and a throttle is arranged on the diversion tube.

The mining chemical anchor cable anchor-unhooking method using the apparatus comprises the following steps: a. preparing an explosive charge connected with a diversion tube, and a specially-made anchor ring on the ground; b. when an anchor cable is installed, installing the specially-made anchor ring between a lock and a pallet, and other processes being the same as the installation process of the anchor cable; c. when mining is carried out on a working face, lagging a hydraulic support column by a cutting depth, and fixing the explosive charge on a roof outside the pallet of the anchor cable; d. connecting one end of the diversion tube to a diversion hole at the upper part of the specially-made anchor ring; an acidic solution in the explosive charge flowing automatically under the action of gravity into a gap between the anchor cable and the specially-made anchor ring via the diversion tube and the diversion hole at the upper part of the specially-made anchor ring to corrode the anchor cable; and allowing a liquid waste from the reaction to be discharged via a diversion hole at the lower side of the specially-made anchor ring; e. setting a warning line at a distance of 0.5 m lagging behind the hydraulic support column to prevent personnel from crossing and prevent the dripping of the mixed acidic solution in the explosive charge from damaging the health of workers; f. after the anchor cable is corroded by the acidic solution, greatly reducing tensile strength, and then utilizing a lagging mining pressure to implement anchor unhooking; and g. after propelling a hydraulic support forward by a cutting depth, repeating c, d, and e until the completion of mining of the entire working face.

The volume of the explosive charge is 100 to 500 mL, and the height of the explosive charge is equal to that of the pallet of the anchor cable.

The acidic solution in the explosive charge is a hydrochloric acid, nitric acid or sulfuric acid solution.

The outer diameter of the specially-made anchor ring is 5 to 30 mm larger than that of the anchor cable lock, and the inner diameter of the specially-made anchor ring is 5 to 10 mm larger than the diameter of the anchor cable.

The flow rate of the acidic solution can be set by means of adjusting the throttle so as to control the time to failure of corrosion of the anchor cable between 1 and 12 hours.

Beneficial effects: Because the above technical scheme is adopted, compared with the prior art, the present invention has the following advantages that: 1. the tensile strength of the anchor cable is weakened by utilizing strong acid to quickly corrode the anchor cable; then the lagging mining pressure is utilized to achieve the effect of damage to the anchor cable, the amount of strong acid is reduced, and the anchor-unhooking operating environment of workers is safer; 2. the controllability of the time to failure of the anchor cable can be realized by means of controlling the concentration of the acidic solution or the flow rate; 3. the diameter of the anchor-unhooking ring is greater than that of the lock, so that the stress focus of the lock on the pallet is reduced, and thus the stress environment of the pallet is improved; and 4. the structure is simple, the operation is easy, the labor intensity is reduced, the anchor-unhooking construction process is simplified, and the promotion is easy.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a schematic cross-sectional view of an anchor cable according to the present invention.

Fig. 2 (a) is a top view of a specially-made anchor ring according to the present invention;

Fig. 2 (b) is a cross-sectional view of the specially-made anchor ring according to the present invention.

In the drawings: 1- anchor cable; 2- explosive charge; 3- diversion tube; 4- throttle; 5-diversion hole; 6- lock; 7- specially-made anchor ring; 8- pallet; and 9- roof.

DETAILED DESCRIPTION

An embodiment of the present invention is further described below in conjunction with the drawings. A mining chemical anchor cable anchor-unhooking apparatus provided by the present invention primarily comprises an explosive charge 2, a diversion tube 3, a throttle 4, a lock 6, a specially-made anchor ring 7 and a pallet 8. The lock 6 and the pallet 8 are sleeved over the exposed section of the anchor cable 1, the specially-made anchor ring 7 is arranged between the lock 6 and the pallet 8, two diversion holes 5 which are longitudinally asymmetrical are formed in the radial direction of the specially-made anchor ring 7, the diversion tube 3 is arranged in the diversion hole 5 at the upper part, and is connected with the explosive charge 2 arranged on a roof 9, and the explosive charge 2 contains a mixed acidic solution having a concentration of 5 to 12 mol/L; and the throttle 4 is arranged on the diversion tube 3. A mining chemical anchor cable anchor-unhooking method provided by the present invention comprises the following steps that: a. preparing the explosive charge 2 connected with the diversion tube 3, and the specially-made anchor ring 7 on the ground, wherein the volume of the explosive charge 2 is 100 to 500 mL, and the height of the explosive charge 2 is equal to that of the pallet 8 of the anchor cable; the explosive charge 2 contains a hydrochloric acid, nitric acid or sulfuric acid solution having a concentration of 5 to 12 mol/L, the throttle 4 is arranged on the diversion tube 3, the specially-made anchor ring 7 is prepared at the same time, the outer diameter of the specially-made anchor ring 7 is 5 to 30 mm larger than that of the anchor cable lock, and the inner diameter of the specially-made anchor ring is 5 to 10 mm larger than the diameter of the anchor cable; and two diversion holes 5 are formed in the upper part at one side and the lower part at the opposite side of the specially-made anchor ring 7, and the specially-made anchor ring 7 is subjected to an anti-corrosion treatment and does not react with the mixed acid; b. when the anchor cable 1 is installed in the gateway tunneling period, installing the specially-made anchor ring 7 between the lock 6 and the pallet 8, and other processes being the same as the installation process of the anchor cable 1; c. when mining is carried out on a working face, lagging a hydraulic support column by a cutting depth of lm, and fixing the explosive charge 2 connected with the diversion tube 3 on the roof 9 outside the pallet 8 of the anchor cable; d. connecting one end of the diversion tube 3 to the diversion hole 5 at the upper part of the specially-made anchor ring 7; the acidic solution in the explosive charge 2 flowing automatically under the action of gravity into a gap between the anchor cable 1 and the specially-made anchor ring 7 via the diversion tube 3 and the diversion hole 5 at the upper part of the specially-made anchor ring 7 to corrode the anchor cable 1; allowing a liquid waste from the reaction to be discharged via the diversion hole 5 at the lower side of the specially-made anchor ring 7; and setting the flow rate of the acidic solution by means of adjusting the throttle 4 so as to control the time to failure of corrosion of the anchor cable, wherein the flow rate of the acidic solution can be set by means of adjusting the throttle 4 so as to control the time to failure of corrosion of the anchor cable 1 between 1 and 12 hours; e. setting a warning line at a distance of 0.5 m lagging behind the hydraulic support column to prevent personnel from crossing and prevent the dripping of the mixed acidic solution in the explosive charge 2 from damaging the health of workers; f. after the anchor cable 1 is corroded by the acidic solution, greatly reducing the tensile strength, and then utilizing a lagging mining pressure to implement anchor unhooking; and g. after propelling a hydraulic support forward by a cutting depth, repeating c, d, and e until the completion of mining of the entire working face. A detailed description of one or more preferred embodiments of the invention is provided above along with accompanying figures that illustrate by way of example the principles of the invention. While the invention is described in connection with such embodiments, it should be understood that the invention is not limited to any embodiment. On the contrary, the scope of the invention is limited only by the appended claims and the invention encompasses numerous alternatives, modifications, and equivalents. For the purpose of example, numerous specific details are set forth in the description above in order to provide a thorough understanding of the present invention. The present invention may be practised according to the claims without some or all of these specific details. For the purpose of clarity, technical material that is known in the technical fields related to the invention has not been described in detail so that the present invention is not unnecessarily obscured.

Throughout this specification and the claims that follow unless the context requires otherwise, the words 'comprise' and 'include' and variations such as 'comprising' and 'including' will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

The reference to any prior art in this specification is not, and should not be taken as, an acknowledgment or any form of suggestion that such prior art forms part of the common general knowledge of the technical field.

Claims

CLAIMS What is claimed is:

1. A mining chemical anchor cable anchor-unhooking apparatus, comprising a lock (6) and a pallet (8) which are sleeved over the exposed section of an anchor cable (1), and characterized in that a specially-made anchor ring (7) is arranged between the lock (6) and the pallet (8), and two diversion holes (5) which are longitudinally asymmetrical are formed in the radial direction of the specially-made anchor ring (7); a diversion tube (3) is arranged in the diversion hole (5) at an upper part of the specially-made anchor ring (7), and is connected with an explosive charge (2) arranged on a roof (9), and the explosive charge (2) contains a mixed acidic solution having a concentration of 5 to 12 mol/L; and a throttle (4) is arranged on the diversion tube (3).
2. A mining chemical anchor cable anchor-unhooking method using the apparatus according to claim 1, characterized by comprising the following steps: a. preparing an explosive charge (2) connected with a diversion tube (3), and a specially-made anchor ring (7) on the ground; b. when an anchor cable (1) is installed, installing the specially-made anchor ring (7) between a lock (6) and a pallet (8), and other processes being the same as the installation process of the anchor cable (1); c. when mining is carried out on a working face, lagging a hydraulic support column by a cutting depth, and fixing the explosive charge (2) on a roof (9) outside the pallet (8) of the anchor cable; d. connecting one end of the diversion tube (3) to a diversion hole (5) at the upper part of the specially-made anchor ring (7); an acidic solution in the explosive charge (2) flowing automatically under the action of gravity into a gap between the anchor cable (1) and the specially-made anchor ring (7) via the diversion tube (3) and the diversion hole (5) at the upper part of the specially-made anchor ring (7) to corrode the anchor cable (1); and allowing a liquid waste from the reaction to be discharged via a diversion hole (5) at a lower side of the specially-made anchor ring (7); e. setting a warning line at a distance of 0.5 m lagging behind the hydraulic support column to prevent personnel from crossing and prevent the dripping of the mixed acidic solution in the explosive charge (2) from damaging the health of workers; f. after the anchor cable (1) is corroded by the acidic solution, greatly reducing tensile strength, and then utilizing a lagging mining pressure to implement anchor unhooking; and g. after propelling a hydraulic support forward by a cutting depth, repeating c, d, and e until the completion of mining of the entire working face.
3. The mining chemical anchor cable anchor-unhooking method according to claim 2, characterized in that a volume of the explosive charge (2) is 100 to 500 mL, and a height of the explosive charge (2) is equal to that of the pallet (8) of the anchor cable.
4. The mining chemical anchor cable anchor-unhooking method according to claim 2 or 3, characterized in that the acidic solution in the explosive charge (2) is a hydrochloric acid, nitric acid or sulfuric acid solution.
5. The mining chemical anchor cable anchor-unhooking apparatus and method according to claim 2, characterized in that a flow rate of the acidic solution can be set by means of adjusting the throttle (4) so as to control a time to failure of corrosion of the anchor cable (1) between 1 and 12 hours.