Excavation Chapter 3

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Author:
athoms
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102561
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Excavation Chapter 3
Updated:
2011-09-18 20:27:00
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exc chp3 test1
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Explosive Formulation
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  1. Explosive Product Formulation

    Achieve: ______
    maximize _______
    minimize ________

    Must have enough _____ to _____

    Must have enough ____ to _____
    • Achieve oxygen balance
    • -maximize explosive energy
    • -minimize toxic gases

    Must have enough combustible/fuel to react with oxygen (instead oxygen with nitrogen)

    Must have enough oxidizing agents (02 carriers) to promote full oxidation of carbon to CO2 instead of CO
  2. Principal reacting ingredients:(4)
    • Fuel
    • Oxidizers
    • Sensitizers
    • Other
  3. Fuel: reacts with ____
    (1+4)
    Oxizider

    • fuel oil
    • carbon
    • aluminum
    • TNT (trinitrotoluene)
  4. Oxidizers: yield ____ to ____
    (1+3)
    oxygen to stimulate combustion

    • ammonium nitrate
    • sodium nitrate (reduces freezing point)
    • potassium nitrate
  5. Sensitizers:
    promote_______ and ______ of
    detonation reaction (2 + 4)
    intiation and propagation of detonation reaction

    • nitroglycerin
    • TNT
    • nitrostarch (non-headache explosive)
    • aluminum
  6. Other (Principal reacting agents)
    (2+2+3)

    Gelling agents:
    Flame retardant:
    Antacids:
    • Gelling agents: bind liquids together,
    • prevent leakage, water proof
    • — nitrocellulose

    • Flame retardant: reduce size duration and
    • temperature of flame of explosion
    • (permissible explosives)
    • — sodium chloride NaCI

    • Antacids: promote stability
    • — calcium carbonate CaCO1
    • — zinc oxide ZnO
  7. Dynamites

    Dynamites which are nitroglycerin based explosives are often called ___ dynamites.

    Originally they were made of pure nitroglycerin absorbed in _____ or _____.

    NG is a blend of two organic _______ ____ namely ______ and _____.


    In today’s NG dynamites the proportion of ______ is less than _____, which lowers the freezing point, provides better heat stability and It is cheaper.

    They also contain nitrocellulose, oxidizing salts and fuels.
    • NG
    • clay or sawdust
    • nitrate esters namely nitroglycerin and nitroglycol
    • nitroglycerin nitroglycol
  8. Sub-classifications of dynamites (2)
    Granular dynamite (Nongelatinous): NG as the explosive base

    • Gelatin dynamite (gelatinous) : mixture of NG and
    • nitrocellulose--> rubbery waterproof compound
  9. Granular dynamite (4)
    • Straight Dynamite
    • High Density Ammonia Dynamite (extra dynamite)
    • Lower density Ammonia Dynamite
    • Granular Permissible
  10. Straight dynamite (no ammonium nitrate)
    made of NG, sodium nitrate (oxygen balance), wood pulp (absorb NG) and carbonaceous fuels

    ___ detonation velocities
    ____ shattering effect
    ___ detonation temperature
    ____ sensitivity
    _____ flammability
    ___ water resistance
    ____ class 3

    _____ for underground, used
    mainly for ditching application
    • High
    • High
    • Low
    • High
    • Very high
    • Fair

    • Unsuitable
    • Fume
  11. High density ammonia dynamite (extra dynamite)

    High density ammonia dynamites are the most widely used cartridged high explosive.

    They have the same composition as straight dynamites except some of the nitroglycerin and sodium nitrate is replaced by ammonium nitrate

    ____ density
    _____ velocity of detonation
    ____ borehole pressure
    ____ heaving action
    _______ water resistance
    ______ fume characteristics

    _____ for dry blasting in relatively soft grounds.
    • Lower
    • Lower
    • Higher
    • Good
    • Relatively poor
    • lmproved

    Preferred
  12. Low density ammonia dynamite:
    Similar in composition to the high density products except more ____ and____ is replaced with ______. ____ strength, useful in ___ rocks.

    Granular permissible
    Same as ammonia dynamites except ___ is added.
    • NG and sodium nitrate
    • ammonium nitrate
    • Lower
    • soft

    salt is added (NaCI)
  13. Gelatin Dynamites
    • Blasting Gelatin
    • Straight gelatin (gelatin dynamite)
    • Ammonia gelatin
    • Semi-gelatin
    • Permissible gelatin
  14. Blasting Gelatin

    Mixture of ___% ___ and __% ___to form a rubbery cohesive gel.

    — They are considered _____.
    — Have the ____ detonating velocities.
    — Emits large volumes of ______.
    — Very ______

    Most powerful of all NG based explosives.
    • 88-92% NG
    • 8-12% nitrocellulose

    • water proof
    • highest
    • toxic gases
    • expensive
  15. Straight gelatin (gelatin dynamite) up to __% ___

    Same as blasting gelatin except_____ and
    _______ and sometimes _____ is added.

    Improved ___
    High ____
    _______
    Fume class - _____ in _____, _____ in ____
    High ______ when _____
    90% NG

    sodium nitrate and carbonaceous fuel and sometimes sulfur

    • oxygen balance
    • density
    • Waterproof
    • good to excellent in lower strength poor in higher strength
    • velocities of detonation when confined
  16. Ammonia gelatin: also called special gelatin or gelatin extra

    It is a straight gelatin in which ____ and ____ is partly replaced with _______.

    Improved _____
    Improved _______
    Improves _______
    Good ________
    High ______
    High ______

    Good for underground work.

    The higher strengths can be used as primer.
    • NG and sodium nitrate
    • ammonium nitrate

    • heaving
    • oxygen balance
    • fume class
    • water resistance
    • density
    • velocity
  17. Semi-gelatin

    They are similar to ammonia gelatin except that more of the __,____ and ____ is replaced by ___ .

    They combine the economy of ammonia dynamites with the strength and some of the water resistance of ammonia gelatin.

    They are ____ water resistant than ammonia gelatins and ____ economical.
    They are ___ water resistant than the ammonia dynamites.

    _____ densities
    _____ velocities
    Often used under ___ conditions and sometimes as primers for _____.
    • NG, nitrocellulose and sodium nitrate
    • ammonia nitrate

    • less
    • more
    • more

    • lower
    • lower
    • wet
    • blasting agents
  18. Permissible gelatin

    Ammonia gelatin or semi-gelatin with ____ added.
    salt (NaCI)
  19. Nitro-Starch Explosives

    Non-headache producing high explosives. All of the ___ is replaced by _____. No ____ sensitizer.

    Do not ____.
    Do not ____.
    ______________________.
    • NG is replaced by nitrostarch
    • liquid

    • freeze
    • leak
    • Adaptable to all kind of applications
  20. Blasting Agents

    An explosive products that meets prescribed criteria for ______ to _____ .
    insensitivity to initiation

    • For storage, any material or mixture consisting of a fuel and oxïdizer,
    • intended for blasting, not otherwise defined as an explosive, provided
    • that the finished product. as mixed and packaged for use or shipment,
    • cannot be detonated by means of a No. 8 test blasting cap when
    • unconfined (BAIT).

    • For transportation, a material designed for blasting which has been
    • tested in accordance with CFR49, Section 173.14a, and found to be so
    • insensitive that there is very little probability of accidental
    • initiation to explosion or transition from deflagration
    • to detonation (DOT)
  21. Blasting Agents (4)
    • Blasting Agent Emulsions
    • Dry Blasting Agents
    • Watergels or Slurries
    • ANFO-Emulsion blends
  22. Dry Blasting Agents (5)
    • ANFO
    • Aluminized ANFO
    • Densified ANFO
    • Heavy ANFO
    • Low Density ANFO
  23. Dry Blasting Agents

    No ____ added.

    ______ is synonymous with dry blasting agent

    Most common of all industrial explosives, in excess of __% of use.

    ANFO is a mixture of ____ and _____.

    Ideal mixture
    ___% Ammonium nitrate (AN)
    ___% Fuel oil (FO)

    Must be oxygen balanced for ________.

    Zero oxygen balance is the point at which an explosive mixture has sufficient ____ to completely ______ all the _____ but have no excess _____ to react with the contained _____.

    At zero oxygen balance all gases are ____ and consist of ___, ____ and ____.
    water

    ANFO

    80%

    fuel oil and porous ammonium nitrate prills

    • 94.3%
    • 5.7%

    optimal energy release

    • oxygen
    • oxidize
    • contained fuels
    • oxygen
    • nitrogen

    • harmless
    • water, carbon dioxide and nitrogen
  24. 94.3% AN - 5.7% FO (oxygen balanced)
    3 NH4NO3 + CH2--> 7 H20 + CO2 + 3N2 + 904 kcal / kg

    92.0% AN - 8.0% FO (fuel excess) not enough oxygen
    2 NH4N03 + CH2 --> 5H2O + CO + 2N2 + 810 kcal/kg

    96.6% AN - 3.4% FO (fuel shortage) excess oxygen
    5 NH4NO3 + CH2 —> 11 H2O + CO2 + 4 N2 + 2 NO + 600 kcal / kg

    formation of CO and NO is ____(___ ___)

    It is generally better to ___ ___ ANFO rather than ____ ____ it.
    endothermic (absorb heat)

    over fuel ANFO rather than under fuel it
  25. Ammonium Nitrate Prills

    Prills are porous, spherical shaped pellets typically between _____ mesh U.S. standard screen size.

    Manufactured by concentrating an ammonium nitrate solution to ___-___%, then _____it. Removal of the moisture during the process produce voids this porosity is carefully controlled.

    Prills are also coated to add certain amount of ______ to prevent caking and allow free flow
    6 to 20

    96-97%, then granulating it

    water resistance
  26. ANFO is the _____ of all explosives and ___ to manufacture. Generally it is _____ and ______ .
    • cheapest
    • simple
    • non-waterproof and free-flowing
  27. It is hard to give exact characteristics of ANFO. They will vary with: (7)
    • fuel oil content and distribution
    • prill size, shape, porosity, density and distribution
    • charge diameter, affects VOD, min 2 inch and 1 inch for crushed prill
    • confinement, affects VOD
    • coupling ratio
    • z water condition, VOD decreases with water, at 10% water will not detonate
    • primer size and type, same size as borehole, multiple for deep holes
  28. Properties of ANFO

    In general ANFO has the following properties:

    ___ weight strength
    ___ bulk strength
    ___ detonation velocity
    ___ detonation pressure
    ___ gas production
    ___ borehole pressure
    ___ Heaving action
    ___ to handle, transport and store
    Relatively ____
    ___ to manufacture
    Bulk mixing on site and direct borehole loading, makes it ___ and ___ _ ___
    • High
    • Low
    • Low
    • Low
    • High
    • High
    • Good
    • Safer
    • cheap
    • Easy
    • safe and quick to use
  29. Problems with ANFO:

    ___ of fuel oil by ____ or ____ can
    result in the generation of _____ quantities of fumes

    can react with some _____ (i.e. ___)

    not ___ ______

    must be ___ _____

    ____ primed for full efficiency

    no ________ in bulk form
    • Loss
    • evaporation or migration
    • hazardous

    • sulfide ores (e.g. pyrite)
    • cap sensitive
    • well confined
    • heavily
    • water resistance
  30. Bulk ANFO

    Blown (pneumatic) or augered from bulk trucks, can be _____
    field mixed
  31. Bagged ANFO

    _____ resistant
    ____ pressure reduced
    • water
    • borehole
  32. Aluminized ANFO

    finely divided aluminum for ____ energy

    81.6% AN - 18.4% Al

    3 NH4NO3 + 2Al -> 6 H20 + AL2O3 + 3N2 + 1975 kcal/kg

    87.6% AN - 2.5% FO - 9.9% AI
    6NH4NO3 + CH2+ 2Al --> 13 H2O + AL2O3 + 6 N2 + CO2 + 1320 kcal/kg
    increased
  33. Cartridged ANFO

    ______ by crushing __% of ____ or adding ____ compounds.
    • Densified
    • crushing 20% of prill or adding iron compounds
  34. Heavy ANFO

    Mixture of ANFO> __% and ___(in varying %)
    Full range of __ depending on %
    Varying degree of _______ depending on %
    Density between ___ and ___
    Weight strength __ than ANFO
    Bulk strength between ___and ___ compared to ANFO of ___
    • 50% and emulsion
    • cost
    • water resistance
    • 1.0 and 1.35
    • less
    • 110 and 150 compared to ANFO of 100
  35. Low Density ANFO

    For _____ blasting near ____structures, or blasting ____, _____ jointed or ___ density rocks which requires _____ shock energy a ___ concentration of energy is needed.

    ANFO diluted with _____ can be used.
    The product is often called ___ or ____.
    Size distribution of the polystyrene is _____ the prill.
    As low as __% prill by volume can be used
    Densities as low as __ or __ can be achieved
    _____ based oil is used as fuel
    Packaged or bulk with tackifying agent to prevent ______
    • controlled
    • sensitive
    • soft, highly jointed or low density
    • minimum
    • low

    • polystyrene bead
    • ISANOL or ANFOPS
    • the same as
    • 25%
    • 0.2 or 0.3
    • Vegetable
    • segregation
  36. ANFO Emulsion Blends

    ANFO is added to some emulsion explosives to ____ their physical characteristics and ___ the rate of detonation.

    As prill concentration ___the water resistance ______

    Common blends contain between __ to __% prill

    Weight strength between __ to __ compared to ANFO at 100

    Densities between __ to __ corresponding to a bulk strength of between ___ and ____.
    • improve
    • slow down

    increases, decreases

    30 to 50%

    • 1.1 to 1.3, 110 and 155
    • 80 to 95
  37. Water gels or Slurries

    They are gelled water-based explosives.

    The continuous phase consists of _____ dissolved in water with ____ ingredients suspended by a ____

    Requires ____ to ____.
    • oxidizing salts
    • solid
    • gelling agent

    chemical or high-explosive sensitizer to detonate
  38. Watergels or Slurries

    Oxidizer salts
    -ammonium nitrate
    -sodium nitrate

    Fuel

    Sensitizer
    - TNT, smokeless powder, nitrostarch, ethylene glycol mononitrate(EGMN), methylamine nitrate, ethanolamine nitrate.
    - Al, air bubbles, monometholamine, micro-balloon or micro-spheres

    Water 10-30%

    Gums, waxes

    Thickener

    Gelling agents (crosslinkers)
  39. Watergel Characteristics

    Relatively _____ compared to ANFO
    ________ in full concentration
    Can be __ or ______
    Densities between __ and ___
    Weight strength ____ ANFO
    Bulk strength_____ as/than ANFO
    VOD ___ than ANFO for similar charge diameter and confinement
    • expensive
    • Water resistant
    • plant or truck mixed
    • 1.0 and 1.35
    • close to
    • considerably greater than
    • greater
  40. Emulsions

    Emulsions are prepared in the form of ____-in-___ emulsions

    The ____ phase is composed of a solution of oxidizer salts suspended as microscopically fine droplets surrounded by a continuous fuel phase

    The mixture is ____ against liquid separation by an _______
    water-in-oil

    internal

    stabilized, emulsifying agent
  41. Composition of Emulsions

    _____ Phase
    .__________


    ______ Phase
    . _______________
    . ______________

    ________ Agents

    ______ Agents for density and sensitivity control
    . _________
    . _________
    . _________
    . _________
    • Internal Phase
    • . solution of oxidizer salts

    • Continuous Phase
    • . water-immiscible fuel
    • . solid fuel (TNT, SP, AI)

    Emulsifying Agents

    • Bulking Agents for density and sensitivity control
    • . air bubbles
    • . glass bubbles
    • . resin beads
    • . plastic beads
  42. Properties of Emulsions

    ___ detonation velocities
    . due to extremely ___ particle size
    . if Al is added VOD _____
    . VOD ___ with ___ in charge diameter
    Densities from __ to __
    ____ detonation pressure
    ____ water resistance
    ____ over wide range of temperatures (200-900F)
    Used for hard ____, ____, ____ for _____
    • High
    • fine
    • decrease
    • decrease with decrease
    • 0.80 to 1.35
    • High
    • High
    • Stable
    • massive rocks, hard toes, booster for
    • ANFO
  43. Matching Explosives Shock and Heave to Blasting Requirements:

    degree of existing fracturing and in-situ block sizes which control the degree of new breakage required

    where significant breakage is needed, rock strength and breakage characteristics control the type and amount of explosive energy required

    the dynamic properties of the rock mass, which controls the ease with which the rock transmits or absorbs dynamic strain energy

    the stiffness or degree of brittleness as opposed to the plasticity of the rock mass which influence its fracture and displacement behavior

    the porosity and density of the rock mass controls the interaction with

    the explosive gases and the time required for burden movement

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