WO1983000357A1

WO1983000357A1 - A method of and apparatus for hydraulic mining

Info

Publication number: WO1983000357A1
Application number: PCT/GB1982/000227
Authority: WO
Inventors: Strathclyde Plc. Anderson
Original assignee: Gill, Arthur
Priority date: 1981-07-24
Filing date: 1982-07-26
Publication date: 1983-02-03
Also published as: BR8207798A; AU8730582A; GB2102047B; JPS58501384A; GB2102047A; CA1181438A; AU547288B2

Abstract

Method of and apparatus for hydraulic retreat mining. This invention provides a method of hydraulic mining which forms a tunnel by stepwise advancing a cylindrical shield (12) housing a cutting boom (13) and gradually erecting a temporary continuous cylindrical tunnel support passage built in longitudinally abutting sections (35) within the formed part of the tunnel. Each section (35) is erected in the space immediately behind the shield when it has advanced a step. On completion of the tunnel the cutting boom (13) is replaced by a high pressure water hose, which hydraulically retreat-mines the exposed face, and the cylindrical passage is gradually dismantled by removing the section adjacent to the shield to enable the shield to retreat stepwise. The apparatus comprises a cylindrical shield (12) housing a removable cutting boom unit (13), means (22) to advance said shield, anchor means (30) to co-operate with said advancing means (22), and cylindrical tunnel support members (35) for stepwise temporary assembly into a space between the advancing shield (12), and the anchor (30), and a high pressure hose to replace the cutting boom when the tunnel (11) is completed and retreat-hydraulic-mining is to be done. The shield (12) includes a rearwardly extending tail skin (12A) to shelter the space (25) immediately behind the shield (12) during erection of a support member. An advantage of the invention is that the tunnel support sections are all recovered during retreat mining without danger to personnel of roof falls during recovery.

Description

A METHOD OF AND APPARATUS FOR HYDRAULIC MINING BACKGROUND OF THE INVENTION

This invention relates to a method of and apparatus for hydraulic mining. In hydraulic mining, a main roadway of arched shaped section is firstly driven into the district to be worked, this roadway being of such dimensions as to permit the transport of material into the mine and the discharge of mineral therefrom simultaneously. From the main roadway are driven a number of tunnels directly into the seams to be extracted and reaching the outmost boundaries thereof. It is the method of and apparatus for the working of one of these tunnels to which the invention relates. The known method of forming these tunnels is to excavate the tunnel using a continuous miner or a rotary cutting boom and then supporting the tunnel with arches. This usually means excavation must cease while arches are erected giving cyclic operation and slow development. Also because of poor profiling, time is spent adequately packing behind the arches or roof falls occur in the unstable ground.

On completion of the tunnel, the excavating machine is withdrawn and replaced with a high pressure water hose or monitor together with a mineral transport system. The water hose is then played on the exposed face to extract the mineral and wash it back to the transport flume. The extraction system gradually retreats back down the tunnel and some of the arches are removed for further use but most are left to give the necessary support to the tunnel in the vicinity of the water hose. Thus not only are most of the arches lost, but there is also a danger to the personnel of roof falls when the arches are salvaged.

An object of the invention is to obviate or mitigate the aforementioned disadvantages. SUMMARY OF THE INVENTION

According to one aspect of the present invention, there is provided a method of hydraulic mining comprising forming a tunnel by stepwise advancing a cylindrical shield housing a cutting boom and gradually erecting a temporary continuous cylindrical passage built in sections within the formed part of the tunnel, each section being erected in the space between the erected portion and the shield when it has advanced a further step, replacing the cutting boom by a high pressure water hose, hydraulically retreat-mining the exposed face, and gradually dismantling the cylindrical passage by removing the section adjacent to the shield to enable the shield to retreat stepwise. According to another aspect of the present invention, there is provided apparatus for use in hydraulic mining, comprising a cylindrical shield housing a removable cutting boom unit, means to advance said shield to form a tunnel using the cutting boom, anchor means to co operate with said advancing means and cylindrical ground support elements for stepwise temporary assembly into a space between the advancing shield and the anchor and a high pressure hose to replace the cutting boom when the tunnel is completed and retreat-hydraulic-mining is to be done.

BRIEF DESCRIPTION OF THE DRAWINGS An embodiment of the present invention will now be described, by way of example with reference to The accompanying drawings, in which:- Fig. 1. is a sectional side elevation of a tunnel showing the apparatus and illustrating the method according to the invention; and

Fig. 2. is an end view.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the drawings the first part 10 of the tunnel 11 is arch shaped in section similar to a conventional roadway and is used initially as a starting chamber and later as a loading station where supplies can be stored and loaded on to a transporter for carrying to or from the face.

Into the starting chamber is introduced a tunnel shield 12 incorporating a gymbal mounted electrically driven cutting boom 13 of known form with a loading scroll 14 and profile guidance ring 15, the latter ensuring that the boom cuts a true circle co-axial with the centre of the gymbal mounting 16 and shield 12.

Also included within the tunnel shield is a flume 20 with water supply, a tunnel support erector 21, (which is optional), hydraulic means 22, e.g. push - pull jacks for advancing and withdrawing the shield, a telescopic hood 23 (which is optional), a hydraulic power pack 24 to supply the needs of the shield, boom and erector, and electrical equipment for controlling the boom and power pack motors. Extending rearwardly of the shield 12 is a cylindrical tail skin 12A which gives an initial support to a space 25 immediately behind the shield and shelters the erector 21 and a work force in that space.

An anchor point 30 is then built behind the shield 12 by rock-bolting to the starting chamber's walls and floors so that the shield can be pushed from it by the jacks 22 into the face and high speed tunnelling begun. The tunnel is formed at a slight upward incline e.g. 8 from the roadway. Where the mineral is soft the telescopic hood 23 is advanced into the face and the cutting boom 13 used to undercut the mineral locally until the hood is fully advanced, thus protecting the face from caving. The remainder of the face is then cut and loaded into the shield flume 20 for transport outby; as the tunnel extends, flume sections 31 are positioned to the rear of the shield 12 and overlapped at the joint 32 with the shield flume 20 to form a continuous outlet from the tunnel. After the first push forward of the shield 12 from the anchor 30, a tunnel support member 35 is erected in the space 25 immediately behind the shield 12. The support member 35 is erected from a number of arcuate elements secured together into a cylindrical wall portion manually or by the mechanical means 21. The length of the tail skin 12A is just greater than the length of a support member 35.

As the shield 12 is advanced stepwise from the anchor 30, and subsequently from the erected members 35, additional support members are erected immediately behind the shield 12 so that the jacks 22 can advance the shield further by engaging the newly added support member. Thus a continuous cylindrical passage is formed behind the shield 12 and shelters the workforce therein.

At the end of the tunnel drivage the gymbal cutting boom is withdrawn therefrom by any convenient means and is replaced with a high pressure water hose or a monitor (not shown) for the hydraulic extraction of the mineral initially beyond the tunnel outer end.

The tunnel supports 35 behind the shield are then removed singly, the shield jacks 22 using these successively to pull the shield 12 back out of the tunnel and at the same time removing the mineral hydraulically as it retreats.

When the shield returns to the starting chamber the anchor point 30 is removed and the shield is ready to be transported to another area.

Ideally, full utilisation is achieved when two shields are used in close proximity, so that the gymbal mounted boom and arcuate elements of the tunnel support members can be transferred from the retreating shield in one tunnel to the advancing shield in another. The advantages in this system are;-

(a) high speed development by excavating and support erection taking place simultaneously,

(b) 100% recovery of segmental ground supports, (c) minimum installation and transfer time from development to production sequence,

(d) mineral transport system installed and utilised during development,

(e) continuous protection of personnel, (f) almost ideal profiling of roadway section, thus giving good strata control with minimum disturbance, and (g) a substantial reduction in the work force.

Claims

1. A method of hydraulic mining comprising forming a tunnel (11) by stepwise advancing a cylindrical shield (12) housing a cutting boom (13) and gradually erecting a temporary continuous cylindrical passage built in sections (35) within the formed part of the tunnel, each section (35) being erected in the space (25) immediately behind the shield when it has advanced a further step, replacing the cutting boom by a high pressure water hose, hydraulically retreat-mining the exposed face, and gradually dismantling the cylindrical passage by removing the section adjacent to the shield to enable the shield to retreat stepwise.

2. A method as claimed in claim 1, including the step of providing anchor means to permit the initial step forward of the shield, and erecting the passage sections between the anchor and the shield.

3. A method as claimed in claim 1 or 2, including the provision of push - pull means on the shield to react against the anchor means and subsequently erected sections to advance or retreat the shield.

4. Apparatus for use in hydraulic mining, comprising a cylindrical shield (12) housing a removable cutting boom unit (13), means (22) to advance said shield to form a tunnel (11) using the cutting boom, anchor means (30) to co-operate with said advancing means (22), and tunnel support members (35) for stepwise temporary assembly into a space (25) between the advancing shield (12) and the anchor means 30, and a high pressure hose to replace the cutting boom when the tunnel (11) is completed and retreathydraulic-mining is to be done.

5. Apparatus as claimed in claim 4, in which the support elements (35) are cylindrical.

6. Apparatus as claimed in claim 4 or 5, in which the support members (35) are erected from a number of elements secured together.

7. Apparatus as claimed in any one of claims 4 to 6, in which the shield (12) includes a rearwardly extending tail skin (12A) to shelter the space (25) immediately behind the shield before and during erection of a support member (35).