WO2004023064A1 - Bourrage de charge - Google Patents

Bourrage de charge Download PDF

Info

Publication number
WO2004023064A1
WO2004023064A1 PCT/IB2003/003838 IB0303838W WO2004023064A1 WO 2004023064 A1 WO2004023064 A1 WO 2004023064A1 IB 0303838 W IB0303838 W IB 0303838W WO 2004023064 A1 WO2004023064 A1 WO 2004023064A1
Authority
WO
WIPO (PCT)
Prior art keywords
hole
stemming
unit
pressure reduction
reduction member
Prior art date
Application number
PCT/IB2003/003838
Other languages
English (en)
Inventor
Howard Harcourt Geach
Immo Eurich Bock
Original Assignee
Howard Harcourt Geach
Immo Eurich Bock
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 Howard Harcourt Geach, Immo Eurich Bock filed Critical Howard Harcourt Geach
Priority to AU2003259434A priority Critical patent/AU2003259434A1/en
Publication of WO2004023064A1 publication Critical patent/WO2004023064A1/fr

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F42—AMMUNITION; BLASTING
    • F42D—BLASTING
    • F42D1/00—Blasting methods or apparatus, e.g. loading or tamping
    • F42D1/08—Tamping methods; Methods for loading boreholes with explosives; Apparatus therefor
    • F42D1/18—Plugs for boreholes
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F42—AMMUNITION; BLASTING
    • F42D—BLASTING
    • F42D1/00—Blasting methods or apparatus, e.g. loading or tamping
    • F42D1/08—Tamping methods; Methods for loading boreholes with explosives; Apparatus therefor

Definitions

  • This invention relates to the stemming of charges in operations and particularly to a method of stemming and to stemming means for use with the method.
  • an explosive or propellant charge or mixture of both In blasting an explosive or propellant charge or mixture of both, generally, but not exclusively, in the form of a cartridge, is placed at or near the bottom of a hole drilled into the material (rock or concrete for example) to be broken. This charge is retained in place by some form of stemming which also serves to at least partially seal the hole so that on ignition of the charge the gases and shock waves pressurize the hole and break the material. Where holes are drilled right through the material into free space, stemming is applied at both ends of the holes.
  • An object of this invention is to provide stemming methods and products that are easy to use and effective in use.
  • a method of stemming a charge in a hole comprises: i. introducing a predetermined amount of particulate stemming material into the hole; ii. inserting a pressure reduction member into the hole to be adjacent the stemming material; iii. introducing a second predetermined amount of particulate stemming material into the hole; and iv. inserting a second pressure reduction member into the hole to be adjacent the stemming material.
  • one of a further charge and a further predetermined amount of stemming material are introduced into the hole to be adjacent to the second pressure reduction member.
  • a plurality of pressure reduction members are inserted in the hole at the entrance thereof.
  • stemming material is compacted using a suitable elongated compacting member.
  • the stemming material is sand and the sand is introduced into the hole in the form of a loosely bonded member and crushed after introduction using a suitable crushing member.
  • the invention also provides a stemming unit comprising loosely bonded particulate in a generally cylindrical form.
  • the stemming unit is one of circular and polygonal cross section and has at least one slot in its outer surface.
  • the stemming unit may include a longitudinal passage in the form of one of a slot and a bore for accommodating cartridge lead wires.
  • the invention also provides a pressure reduction member having one of a circular and polygonal perimeter.
  • the pressure reduction member may be substantially flat or may be of a hollow conical or frusto conical configuration.
  • the pressure reduction member may have a hole therethrough and/or a slot extending inwardly from the perimeter thereof.
  • the pressure reduction member is a disc made of flexible sheet material and has a segment removed therefrom.
  • the pressure reduction member may be of plastics, metal, ceramics or a combination thereof.
  • Figure 1 is an elevation of a stemming unit according to the invention
  • Figure 2 is an end elevation of the stemming unit
  • Figure 3 is a side elevation of a pressure reduction member according to the invention.
  • Figure 4 is a plan of the pressure reduction member
  • Figures 5 to 7 are schematic sectional elevations of a hole in a working face depicting the use of the stemming unit and pressure reduction member;
  • Figure 8A & 8B are perspective views of a second embodiment of a pressure reduction member;
  • Figure 9 is a perspective view of a third embodiment of a pressure reduction member;
  • Figure 10 is a perspective view of a fourth embodiment of a pressure reduction member.
  • the stemming unit in this embodiment is a sand core of elongated right circular cylindrical construction having two ends (2) and the axial length of which may vary from about 50mm up to 500mm or more, depending upon the application and diameter of the hole to be stemmed.
  • the sand cores are manufactured such that its diameter is less than that of the hole to be stemmed, thus allowing for it to be easily inserted into the hole.
  • the sand core generally comprises a mixture of heavy mineral sands, chamotte and silicaceous or quartzitic sands. However, any suitable particulate material can be used.
  • the sand core also comprises of a combination of particle sizes, the largest in diameter being approximately 1/16 th of the diameter of the shot hole and the smallest being fines measuring lOmicron or less.
  • a passage (3) in the form of a groove or slot is located in the cylindrical surface (4). This recess extends to approximately the centre (not shown) of the unit (1 ).
  • This feature creates a greater surface area, which is designed to expedite the absorption of water into the sand core and it also makes the sand core more susceptible to crushing when axial force is applied by means of a charging stick.
  • This innovation allows dry and therefore lighter sand cores to be transported to the place of use and allows the increase in the mass of the sand core by immersing it in water prior to inserting it into the shot hole.
  • the water absorption capacity of the sand cores gives rise to enhanced friction against the side wall of the shot hole and to increased inertial capacity, both of which characteristics enhance the ability of this stemming system to confine high pressure deflagration gasses within the shot hole.
  • the sand cores are also able to absorb chemicals to suppress either or both dust and fumes that may be generated by the explosive or propellant charges.
  • This aspect of the design has two further key innovative aspects: a) it facilitates the process of stemming by not subjecting the cartridge lead wires to damaging pressure during the stemming process and, b) it centers the leads in the hole, thereby effectively insulating the wires from rogue currents induced into rock by the blasting process.
  • the unit (1) is cast from sand using conventional gas or resin casting techniques. Bonding agents used are chosen in both type and volume to be such that while the unit retains its form during transport and loading (as described hereafter) it may be relatively easily crushed by impact with a suitable tool.
  • FIGS 3 and 4 depict a pressure reduction member for use in the stemming method of the invention.
  • This member (5) is of a hollow conical configuration and is made from a suitable plastics material which is substantially rigid but has some flexibility in use.
  • a central aperture (6) is connected to the outer periphery (7) by way of a slot (8).
  • the stemming unit (1) and the pressure reduction member (5) are used together in a stemming method provided for by the invention and which is depicted in figures 5, 6 and 7 of the drawings.
  • a stemming unit (1 ) is positioned adjacent this cartridge.
  • the diameter of the stemming unit (1) is such that it slides easily into the hole (13).
  • the operation lead wires (15) of the cartridge are positioned into the slot (3) of the unit (1 ) so that they are not damaged by the positioning of the unit (1 ) or subsequent operational steps.
  • a pressure reduction member (5) is positioned such that the apex thereof points towards the bottom (12) of the hole (13) and it is in contact with the sand (17) of the crushed unit (1).
  • the process is repeated with a second stemming unit (1B) and pressure reduction member (5B). Further stemming units and pressure reduction members may be added until the hole (13) has been stemmed. Alternatively further charges could also be positioned along the length of the hole (13) and spaced by the stemming units (1) to create a decked charge.
  • a composite pressure reduction member comprising two or more standard pressure reduction members joined together may be placed at the collar or entrance of the hole to further enhance the efficiency of the stemming system.
  • the combination of the crushed stemming unit (1) and pressure reduction members (5) is designed to create a composite stemming column that exploits the labyrinth theory of pressure reduction seals in the following manner:
  • the small gap causes an accumulation of sand and grit particles, with the larger particles locking into the gap between the member and the sides of the drill hole.
  • the gas that escapes while the gap is being obstructed by sand particles of different sizes then leaks into the next zone and starts to fluidise the next sand unit (1).
  • This process repeats itself along the length of the stemming column towards the entrance of the hole (13). This process also induces reflecting acoustic Shockwaves within the hole (13), which encourages the enlargement of micro-fractures that are already present in the material.
  • This method does not seek to prevent totally the progress of gasses through the stemming column towards the entrance of the hole (13), rather it is designed provide a pressure reduction seal which interferes with the escape of these gasses via the hole for a time long enough to have the result that the deflagration or explosion gasses preferentially escape to the atmosphere by entering micro fractures, either naturally present or induced by the drilling process, and splitting or shearing the material open to the free face. In this manner rock and consolidated materials can be effectively broken using a propellant cartridge system.
  • the central hole (6) of the member (5) is designed to just allow it to ride around the carti Je leads (15).
  • the effect of this design is to minimize pressure losses through the hole (13) and also to keep the cartridge leads (15) centred within the shot hole.
  • the design effect is that the stemming system as whole assists accurate sequential firing by insulating the electronic initiator and the cartridge leads from rogue currents.
  • Centralising the conducting wires also assists in minimising the interference effects of electronic plasma shock waves induced during the blasting process. Such electric interference can cause out of sequence firing, misfires and blow-outs.
  • Rock and other hard consolidated materials are most effectively broken by the application of rapidly alternating compressive and tensile forces, such as are created by reflecting acoustic Shockwaves.
  • This stemming column design generates such Shockwaves and together with the effective containment of high pressure gasses within the hole, forcing these gasses to enter and enlarge micro-fractures in the material and effect the splitting and shearing of the material towards the free face.
  • This stemming column design also has the effect, through effective containment of the deflagration gasses, of promoting the complete burning and efficient oxidation of potentially noxious deflagration by-products caused by incomplete oxidation of the fuels in the cartridge.
  • the stemming unit can have any suitable configuration as can the pressure reduction member.
  • the pressure reduction member (80) can be a disc made of flexible sheet material and having a segment (81) removed therefrom.
  • the ends (82) of the perimeter on the segment (81) are brought together to make the disc assume a conical shape as shown in Figure 8B. This can conveniently be done by inserting the disc into a hole on the end on a tool (not shown).
  • This configuration has the added advantage that as the material tries to flex back to its original shape it creates a tighter fit in the hole into which it is inserted.
  • the pressure reduction member (90) can simply be a disc with a central aperture (91).
  • a pressure reduction member (100) can have a disc (101) secured to the apex of a hollow cone (102) with an aperture extending centrally through the disc (101) and cone (102).
  • the disc (101) serves to stabilise the apex of the cone (102) in a hole while the base of the cone resists ejection on the pressure reduction member from the hole.

Landscapes

  • Life Sciences & Earth Sciences (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Drilling And Exploitation, And Mining Machines And Methods (AREA)

Abstract

L'invention concerne un procédé de bourrage d'une charge dans un trou (13), comprenant les étapes suivantes : introduction d'une quantité prédéterminée d'un matériau de bourrage particulaire (1) dans le trou (13) ; insertion, dans le trou (13) au voisinage dudit matériau de bourrage (1), d'un élément de réduction de pression (5) ; introduction, dans le trou (13), d'une seconde quantité prédéterminée (1B) de matériau de bourrage particulaire ; et insertion, dans le trou (13) au voisinage du matériau de bourrage (1B), d'un second élément de réduction de pression (5B). On constitue ainsi un joint de réduction de pression qui n'est pas particulièrement destiné à empêcher totalement la progression des gaz à travers la colonne de bourrage, en direction de l'entrée du trou (13), mais plutôt à entraver l'échappement de ces gaz via le trou (13) pendant une durée suffisamment longue pour que les gaz de déflagration ou de l'explosion s'échappent de préférence dans l'atmosphère en traversant des microfractures, soit présentes naturellement, soit provoquées par le forage, et en séparant ou cisaillant le matériau débouchant vers la face libre.
PCT/IB2003/003838 2002-09-09 2003-09-09 Bourrage de charge WO2004023064A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU2003259434A AU2003259434A1 (en) 2002-09-09 2003-09-09 Stemming

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
ZA2002/7193 2002-09-09
ZA200207193 2002-09-09

Publications (1)

Publication Number Publication Date
WO2004023064A1 true WO2004023064A1 (fr) 2004-03-18

Family

ID=31979081

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/IB2003/003838 WO2004023064A1 (fr) 2002-09-09 2003-09-09 Bourrage de charge

Country Status (3)

Country Link
AU (1) AU2003259434A1 (fr)
WO (1) WO2004023064A1 (fr)
ZA (1) ZA200501828B (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106225616A (zh) * 2016-09-14 2016-12-14 中国地质大学（武汉） 一种防露天炮孔被堵的堵孔器

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE211828C (fr) * 1900-01-01
US4754705A (en) * 1986-11-17 1988-07-05 The Curators Of The University Of Missouri Mechanical stemming construction for blast holes and method of use
BE1005955A3 (fr) * 1992-06-05 1994-04-05 Carrieres Et Fours A Chaux De Procede de chargement d'un puits de tir de mines.
US6324980B1 (en) * 1998-05-08 2001-12-04 Cesar Estevez Bianchini Conical plug for sealing blastholes in open cut mining

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE211828C (fr) * 1900-01-01
US4754705A (en) * 1986-11-17 1988-07-05 The Curators Of The University Of Missouri Mechanical stemming construction for blast holes and method of use
BE1005955A3 (fr) * 1992-06-05 1994-04-05 Carrieres Et Fours A Chaux De Procede de chargement d'un puits de tir de mines.
US6324980B1 (en) * 1998-05-08 2001-12-04 Cesar Estevez Bianchini Conical plug for sealing blastholes in open cut mining

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106225616A (zh) * 2016-09-14 2016-12-14 中国地质大学（武汉） 一种防露天炮孔被堵的堵孔器

Also Published As

Publication number Publication date
ZA200501828B (en) 2007-05-30
AU2003259434A1 (en) 2004-03-29

Similar Documents

Publication Publication Date Title
AP880A (en) Method and apparatus for controlled small-charge blasting of hard rock and concrete by explosive pressurisation of the bottom of a drill hole.
RU2081313C1 (ru) Устройство для разрушения материалов твердых плотных скальных пород и бетона и способ разрушения материалов твердых плотных скальных пород и бетона
US20240060377A1 (en) Ballistically actuated wellbore tool
WO1997006402A9 (fr) Sautage regule avec petite charge d'explosif
CA2043926C (fr) Cone adhesif de tir secondaire
EA007198B1 (ru) Портативное устройство для разрушения горной породы
CA2373760A1 (fr) Cartouche et systeme de chargement comprenant cette cartouche
AU2006220766B2 (en) Handheld pneumatic tool for breaking up rock
ZA200501828B (en) Stemming
EP1463918B1 (fr) Procede et appareil servant a casser la roche
KR100317825B1 (ko) 미진동 암반파쇄방법
RU2234673C1 (ru) Способ взрывания восходящих скважин
RU2107255C1 (ru) Шланговый заряд с регулируемым энерговыделением для отделения блочного камня
CN115388723B (zh) 大断面洞穴爆破结构和爆破方法
JPS6051039B2 (ja) スム−スブラステイング発破工法
RU2060448C1 (ru) Способ ведения буровзрывных работ на карьерах
SU1670643A1 (ru) Способ возбуждени сейсмических волн
KR20040016534A (ko) 중공구조를 사용하는 장약
MXPA98001011A (en) Method and apparatus for controlled explosion of small load of rock and concrete, by explosive pressurization of the fund of a perforated hole

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NI NO NZ OM PG PH PL PT RO RU SC SD SE SG SK SL SY TJ TM TN TR TT TZ UA UG US UZ VC VN YU ZA ZM ZW

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): GH GM KE LS MW MZ SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LU MC NL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
WWE Wipo information: entry into national phase

Ref document number: 200501828

Country of ref document: ZA

122 Ep: pct application non-entry in european phase
NENP Non-entry into the national phase

Ref country code: JP

WWW Wipo information: withdrawn in national office

Country of ref document: JP