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WO2003058032A1 - Procede et appareil d'exploitation charbonniere par longue taille - Google Patents

Procede et appareil d'exploitation charbonniere par longue taille Download PDF

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Publication number
WO2003058032A1
WO2003058032A1 PCT/AU2003/000027 AU0300027W WO03058032A1 WO 2003058032 A1 WO2003058032 A1 WO 2003058032A1 AU 0300027 W AU0300027 W AU 0300027W WO 03058032 A1 WO03058032 A1 WO 03058032A1
Authority
WO
WIPO (PCT)
Prior art keywords
bolt
shaft
shank
trailing end
support plate
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/AU2003/000027
Other languages
English (en)
Inventor
Jeffrey Robert Fergusson
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to AU2003201199A priority Critical patent/AU2003201199B2/en
Publication of WO2003058032A1 publication Critical patent/WO2003058032A1/fr
Priority to PCT/AU2004/000021 priority patent/WO2004063531A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
    • E21D21/00—Anchoring-bolts for roof, floor in galleries or longwall working, or shaft-lining protection
    • E21D21/008—Anchoring or tensioning means
    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21C—MINING OR QUARRYING
    • E21C41/00—Methods of underground or surface mining; Layouts therefor
    • E21C41/16—Methods of underground mining; Layouts therefor
    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
    • E21D21/00—Anchoring-bolts for roof, floor in galleries or longwall working, or shaft-lining protection
    • E21D21/0006—Anchoring-bolts for roof, floor in galleries or longwall working, or shaft-lining protection characterised by the bolt material

Definitions

  • the present invention relates to mining and, in particular, to retreating longwall coal mining.
  • Each block may be 200 metres wide and
  • rib bolts temporary rock bolts
  • wall bolts permanent rock bolts
  • the wall bolts have been solid and are fabricated from steel.
  • the rib bolts have likewise been solid and fabricated from steel.
  • the rib bolts have been solid and been fabricated from fibreglass.
  • the solid steel rib bolts suffer from the problem that they bend around the coal cutting teeth (shaped like picks) of the longwall mining machine. This fouls the machine and causes an expensive delay in mining whilst the machine is cleared. Also the solid steel rib bolts tend to damage the conveyor(s) which initially convey the coal from the ribs within the mine.
  • a major advantage of the solid steel rib bolts is that they are magnetically permeable. Thus they can be removed from the downstream coal flow by passing the coal under a magnet field. The steel bolts are thus able to be easily extracted.
  • the fibreglass bolts are still liable to damage the conveyor belts and, of course, cannot be magnetically removed from the coal.
  • the fibreglass tends to float in a coal washing plant flotation tank used in downstream processing.
  • the fibreglass in the coal has various deleterious side effects and thus the miner generally receives a lower price for the coal from the customer if pieces of fibreglass are present in the coal.
  • Some customers demand that no fibreglass be present in the coal.
  • $A500,000 (US$250,000) approximately has recently been spent on research projects in Australia, to try to overcome this problem by putting steel fibres in the fibreglass in the hope that it could then be magnetically extracted - but without success.
  • the aim of the present invention is to overcome, or at least ameliorate, the abovementioned problem by the use of magnetically permeable tubular rock bolts which are thus designed to shear into relatively small pieces when the longwall mining machine encounters same, and can, of course, be magnetically removed or sink during downstream processing.
  • a further problem is that the surface into which the rock bolt is embedded may be friable. This is a particular problem with coal mining because some coals, in particular, are quite soft. The problem afflicts both rib bolts and wall bolts as referred to above. In addition, a similar problem can arise in relation to "hard rock" or metalliferous mining where the rock itself is friable or liable to crumble. This problem is that the bolt as initially installed supports the rock face by means of a support plate which compresses the rock. Thereafter, however, the rock or coal is liable to crumble away leaving the support plate either no longer in contact with, or no longer compressing, the rock face.
  • a further aim of the present invention is to address this problem also by providing a means and method whereby the original rock bolt can effectively be re-tensioned.
  • a method of retreating longwall coal mining comprising the steps of extracting in turn each of a plurality of longwall blocks between each of which a pillar of coal is left standing, and during or immediately following creating of development headings to define the extent of a longwall block, temporarily stabilizing the ribs of the longwall block utilizing a plurality of rib bolts inserted into said ribs, characterized in that said rib bolts are formed from tubular magnetically permeable material having a strength permitting said bolts to be sheared by longwall mining machinery.
  • a rib bolt for use in longwall coal mining, said bolt comprising a tubular shaft closed at its leading end and open at its trailing end, and a drive means secured to said trailing end to permit rotation of said rib bolt about its longitudinal axis, said shaft having a strength permitting same to be sheared by longwall mining machinery, and said shaft and drive means being fabricated from magnetically permeable material.
  • a rock bolt having a hollow shaft with a leading end and a trailing end and being adapted to be re- tensioned against a friable rock face into which the bolt is to be inserted with said shaft immobilised, said bolt having a support plate through which said shaft passes and located adjacent said trailing end, said trailing end having an internally threaded end portion which on normal installation bears against said support plate, a cupped member having a threaded shaft threadably received in said end portion with said shank at least partially protruding into said shaft, said cupped member extending around and beyond said end portion to bear against said support plate, whereby, in the event of said rock face crumbling away adjacent said support plate, said shank can be rotated relative to said end portion to advance said cupped member and force said support plate away from said end portion to re-engage said support plate with said crumbled rock face.
  • a method of re-tensioning a rock bolt having a hollow shaft with a leading end and a trailing end which shaft is immobilised in a friable rock face, said bolt further having said shaft passing through a support plate intended to bear against said rock face at the urging of an internally threaded end portion at said trailing end of said shaft, said method in the event of said rock face crumbling away adjacent said support plate comprising the steps of: (i) threadably engaging a threaded shank of a cupped member with said internally threaded end portion whereby said shank at least partially protrudes into said hollow shaft, (ii) rotating said shank relative to said shaft to extend said cupped member around and beyond said end portion to bear against said support plate and urge same against said crumbled rock face.
  • FIG. 1 is a schematic perspective view of a retreating longwall coal mine in operation
  • Fig 2 is a truncated perspective view of a rib bolt in accordance with the preferred embodiment
  • Fig 3 is an exploded perspective view of the rib bolt including a load distributing plate and a support member
  • Fig 4 is an exploded longitudinal cross-section through an installed bolt of a second embodiment
  • Fig 5 is a view similar to Fig 4 but of a still further embodiment.
  • a coal mine has a central drive 1 off which to either side extend a plurality of side drives termed development headings 2, 3, 4 and 5 (only headings to one side of the central drive 1 being illustrated).
  • the length of each of the headings 2 - 5 is of the order of 2000 metres.
  • the distance between the headings 2, 3 and 4, 5 (which defines the width of the corresponding longwall blocks 7, 8) is of the order of 200 metres.
  • Between the headings 3 and 4 is defined a pillar 9 of coal to be left in situ after the mining has finished.
  • the width of the pillar 9 is of the order of 20 - 30 metres.
  • a long wall mining machine attacks the face of the longwall block 7 and discharges coal onto a conveyor 12 in the development heading 2 which in turn discharges the coal onto another conveyor 13 in the central drive 1.
  • the ribs of the longwall block 7, 8 and pillar 9 need to be stabilized to prevent the ribs crumbling or collapsing. This is done by means of rib bolts 17 driven into the ribs of the longwall blocks 7, 8 and by means of wall bolts 19 driven into the ribs of the pillars 9.
  • the wall bolts 19 are intended to be permanent and are usually solid steel bolts each having a diameter of approximately 16mm and which are intended to be mechanically fixed or anchored, or embedded within resin in a corresponding hole of from 25 to 30mm diameter.
  • the rib bolts 17 are only temporary and are intended to be shortly devoured by the longwall mining machine 10. As explained above the rib bolts 17 have hitherto either been solid steel bolts or solid fibreglass bolts with the above described disadvantages.
  • rib bolt 117 which is fabricated from a hollow steel shaft 22 which, whilst embedded in resin, is intended to shear into pieces when the longwall mining machine encounters the rib bolts 117.
  • rib bolt 117 of the preferred embodiment has a shaft 22 which is a hollow cylinder of indefinite length.
  • the shaft 22 is preferably fabricated from conventional steel pipe and preferably has a nominal bore of from 10-30 mm approximately.
  • the shaft 22 has a tip 23 or leading end which is swaged closed so as to create four impellers 24 which are used to shred the resin cartridge and mix the resin or grout used to hold the shaft 22 of the rib bolt 117 in position.
  • a domed washer 25 and an hexagonal nut 26 are secured by a means of a frictional press fit, by welding, by threaded engagement, or by some other conventional such means.
  • the interior of the nut 26 is provided with an internal thread 27 which, if desired, is able to be threadably engaged with an external thread 29 on the shank 30 of a support member 31.
  • a typical support member 31 is fabricated from a conventional bolt to which is welded a U-shaped link 32. Such support members can be used to support temporary lights, warning signs, etc.
  • the shaft 22 is passed through a support plate 37 which has a recessed collar 38 which mates with the convex face of the domed washer 25.
  • a two-part epoxy resin or grout surrounds the shaft 22 and fills the space between the shaft 22 and the hole (not illustrated).
  • This quick setting resin or grout secures the bolt in position and a hollow tubular spanner (conventional but not illustrated) is used to drive the rock bolt 117 so as to rotate it about its longitudinal axis during the installation procedure.
  • This drives the washer 25 and nut 26 into the recessed collar 38 and ensures that the support plate 37 compresses the coal in the vicinity of the hole. The result is that the coal is stabilized.
  • the support member 31 is able to be threadably engaged with the nut 26.
  • Mine services are then supported by means, for example, of a chain and shackle or D-bolt which engages the U-link 32.
  • the shaft 22 is preferably provided with a plurality of keying deformations 28 (only some of which are illustrated) along its length in known fashion (eg. by helically rolling). This ensures good keying between the grout and the shaft 22.
  • the deformations 28 preferably are intermittent and have a V-shaped profile or cross-sectional shape. The deformations substantially assist in permitting the shaft 22 to break up under the action of the long wall mining machine 10.
  • the largest size given in the above table represents the current practical limit to enable the nut 26 to be engaged by spanners able to be accommodated by present day bolt insertion machinery.
  • a particular advantage of the above described arrangements is that a wide range of tubular stock is readily available to suit urgent requests for manufactured rock bolts.
  • the availability extends not only to size but also to the grade of material.
  • pipe with a nominal bore of 22 mm is available in a range of metal qualities which result in a typical range of ultimate tensile strengths (UTS) of from 8 to 15 tonnes.
  • UTS ultimate tensile strengths
  • the shaft 22 of the rib bolt 117 is sufficiently weak that it can be sheared by the longwall mining machine 10.
  • conventional JUMBOLTS could not be used as rib bolts 117 without encountering the same problems as conventional solid steel rib bolts.
  • support member 131 can also be provided as illustrated in Fig. 4.
  • the support member 131 takes the form of a threaded shank 129 mounted within a cup 130 having a cylindrical side wall 140.
  • a nut 126 is welded to the cap of the cup 130.
  • the shank 129 and nut 126 can also be formed as a conventional bolt which passes through the cap of the cup 130.
  • Fig. 4 also illustrates a domed washer 125 which is slidably mounted on the bolt 117 rather than being fixed thereto, by welding for example, as illustrated in Figs. 2 and 3.
  • the nut 26 is provided with a hole 200 into which a breakable pin 201 is inserted by means of a friction fit.
  • the shank 129 can then have its tip only partially threadably inserted into the nut 26 until the tip of the shank 129 abuts the pin 201.
  • the entire bolt 117 can be mounted in the hole in the rock or coal face 150 but with the conventional driving machinery engaging the nut 126 rather than the nut 26. In this way the support plate 37 is driven against the coal face 150 in the usual way.
  • the support plate 37 can be brought to bear against the new face 150 in the following fashion.
  • the nut 126 is rotated thereby causing the shank 129 to rotate relative to the nut 26 which is now fixed by hardened grout.
  • the shank 129 therefore fractures the pin 201 and progresses through the nut 26 until the front edge of the support member 131 bears against the support plate 37.
  • This re-engagement of the support plate 37 against the face 150 can be repeated several times, if necessary.
  • the nut 126 and shank 129 can be replaced with an equivalent nut and longer shank, if necessary.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mining & Mineral Resources (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Geology (AREA)
  • Structural Engineering (AREA)
  • Remote Sensing (AREA)
  • Combined Means For Separation Of Solids (AREA)

Abstract

L'invention concerne une technique d'exploitation charbonnière par longue taille dans laquelle des boulons à blocage automatique à tube d'acier (117) sont utilisés pour stabiliser provisoirement le charbon de blocs de longue taille (7, 8) avant qu'ils ne soient consommés par une abatteuse par longue taille classique (10). Cette machine (10) rompt la tige du tube d'acier (22) des boulons (117). Ces pièces en acier peuvent ensuite être enlevées du charbon extrait par attraction magnétique. L'invention concerne également un procédé et un appareil permettant de remettre sous tension les boulons d'ancrage dans une surface rocheuse friable (150). Un capuchon cylindrique (130) enveloppant l'écrou (26) repose sur la plaque de support (37). Ce capuchon (130) comprend une queue filetée (129) qui s'enfonce dans l'écrou (26).
PCT/AU2003/000027 2002-01-11 2003-01-10 Procede et appareil d'exploitation charbonniere par longue taille Ceased WO2003058032A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
AU2003201199A AU2003201199B2 (en) 2002-01-11 2003-01-10 Longwall mining method and apparatus
PCT/AU2004/000021 WO2004063531A1 (fr) 2003-01-10 2004-01-08 Remise sous tension d'un boulon d'ancrage

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
AUPR9939 2002-01-11
AUPR9939A AUPR993902A0 (en) 2002-01-11 2002-01-11 Longwall mining method and apparatus

Publications (1)

Publication Number Publication Date
WO2003058032A1 true WO2003058032A1 (fr) 2003-07-17

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Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/AU2003/000027 Ceased WO2003058032A1 (fr) 2002-01-11 2003-01-10 Procede et appareil d'exploitation charbonniere par longue taille

Country Status (2)

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AU (1) AUPR993902A0 (fr)
WO (1) WO2003058032A1 (fr)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN100363591C (zh) * 2005-02-01 2008-01-23 史记 立井群井下无人采煤法
EP2186995A2 (fr) 2008-11-13 2010-05-19 HILTI Aktiengesellschaft Elément de fixation pour l'utilisation dans la construction minière ou de tunnels
CN104763425A (zh) * 2015-02-03 2015-07-08 杨洪兴 一种卸压预裂爆破沿空留巷无煤柱开采方法
CN107023311A (zh) * 2017-06-08 2017-08-08 刘冲 煤柱下方巷道修复方法
CN114251111A (zh) * 2020-09-27 2022-03-29 中国矿业大学(北京) 综放末采阶段顶煤内嵌式支护方法及系统

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113236253B (zh) * 2021-05-28 2023-04-28 辽宁科技大学 一种无底柱分段崩落法远距离自动折管覆盖岩注浆方法

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3145923A1 (de) * 1981-11-20 1983-06-01 Dyckerhoff & Widmann AG, 8000 München Verankerung fuer ein ankerzugglied, insbesondere fuer einen felsanker
US5542788A (en) * 1993-11-12 1996-08-06 Jennmar Corporation Method and apparatus for monitoring mine roof support systems
US20020064429A1 (en) * 2000-11-25 2002-05-30 Robertson Roy Lee Method and apparatus for re-tensioning a roof bolt in an underground mine

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3145923A1 (de) * 1981-11-20 1983-06-01 Dyckerhoff & Widmann AG, 8000 München Verankerung fuer ein ankerzugglied, insbesondere fuer einen felsanker
US5542788A (en) * 1993-11-12 1996-08-06 Jennmar Corporation Method and apparatus for monitoring mine roof support systems
US20020064429A1 (en) * 2000-11-25 2002-05-30 Robertson Roy Lee Method and apparatus for re-tensioning a roof bolt in an underground mine

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN100363591C (zh) * 2005-02-01 2008-01-23 史记 立井群井下无人采煤法
EP2186995A2 (fr) 2008-11-13 2010-05-19 HILTI Aktiengesellschaft Elément de fixation pour l'utilisation dans la construction minière ou de tunnels
DE102008043702A1 (de) 2008-11-13 2010-05-20 Hilti Aktiengesellschaft Befestigungselement für den Einsatz im Berg- und Tunnelbau
AU2009233650B2 (en) * 2008-11-13 2011-04-07 Hilti Aktiengesellschaft Fastening element for use in mining and tunnel construction
CN104763425A (zh) * 2015-02-03 2015-07-08 杨洪兴 一种卸压预裂爆破沿空留巷无煤柱开采方法
CN107023311A (zh) * 2017-06-08 2017-08-08 刘冲 煤柱下方巷道修复方法
CN114251111A (zh) * 2020-09-27 2022-03-29 中国矿业大学(北京) 综放末采阶段顶煤内嵌式支护方法及系统
CN114251111B (zh) * 2020-09-27 2023-02-21 中国矿业大学(北京) 综放末采阶段顶煤内嵌式支护方法及系统

Also Published As

Publication number Publication date
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