Voladura

1. Explosive Types

2. Explosive Types
 Black Powder
 Dynamites
 Water Gels/Slurries
 Emulsions
 AN/FO - Blasting Prills
 Blends
 Boosters
 Two Component Products

3. Black Powder
 Mixture of potassium
nitrate, sulfur, and
charcoal
 Documented back to
the early 1200’s
 Hard to manufacture
safely.

4. Dynamite
 Around for approximately 130 years
 Alfred Nobel discovered that by mixing Nitroglycerin
with kieselguhr, it made it safer to transport.
 Kieselguhr is a diatomaceous earth

5. Types of Dynamites
 Granular
 Straight Granular
 Ammonia Granular
 Semi-Gelatin
 Gelatin
 Straight Gelatin
 Ammonia Gelatin
 Permissibles

6. Dynamites
 Straight
NG absorbed into an inert material
(kieselguhr)
Eventually replace inert material with
active ingredients (sodium nitrate, an
oxidizing agent, and wood pulp)
Percentage of NG described the grade
(50% NG was called 50% Straight Dynamite)

7. Dynamites (Granular)
 Ammonia (a.k.a. Extra Dynamites)
Ammonium nitrate replaces NG as primary
energy source.
Weight Strength of AN is approximately 70%
of NG
Comparison to Straight Granular
 Lower in detonation velocity
 Less sensitive to shock or friction
 Less flammable
 Less water resistant
 More economical

8. Dynamites (Gelatin or Semi-Gelatin)
 Semi-gelatin
 The gelling process gives the following benefits
 Better water resistance
 Gives a more cohesive mixture
 Low-fume generation characteristics
 Ammonia dynamites which contain a small amount of
nitrocotton as a gelling agent.

9. Dynamite (Gelatin or Semi-Gelatin)
 Straight Gelatin
 Contains high amounts of nitroglycerin and nitrocotton
 “Rubberlike” consistency gives excellent water resistance
 Sodium nitrate and various carbons were added to
improve oxygen balance
 Ammonia Gelatin
 Ammonium nitrate substituted for some of the NG
 This formed a plastic cohesive product with good water
resistance
 Also gave higher densities, velocities and detonation
pressures. (good booster qualities)

10. Dynamite
 Permissible Dynamites
 Must pass MSHA regulations for use in
underground coal
 Some forms of ammonia gelatin and
ammonia granular are approved
 A flame suppressant is added to the
standard formulas to gain permissible
approval (e.g. salt)
 Many permissibles used to have a NG
replacement

11. Water Gels/Slurries
 Consist of oxidizing salts (AN) and fuels (DFO)
dissolved or dispersed in a continuous liquid
phase (water).
 Advantages
 Thickening agents are either added at the hole for
bulk, or added at manufacturing for package.
 Density ranging from 0.8 to 1.4 (exception1.6) [g/cc]
 Provides more energy per unit volume than AN/FO
 Excellent water resistance
 Replaced some NG package products (sensitivity)

12. Water Gels/Slurries
 Disadvantages
 Cost of chemical sensitizers
 Low Temperature problems
 Cannot be made in a
continuous process. All
batch product.

13. Emulsions
 Microscopic oxidizing agents surrounded by a fuel
with an emulsifying agent added to stop separation

14. Emulsions
 Water gels are not as uniform in structure

15. Emulsions
 Advantages
 Excellent water resistance
 Pumpable at low temperatures
 Good Shelf Life
 Sometimes AN prill or Aluminum will be
added to increase the gas energy
 Can be made in a continuous process

16. Emulsions
 Microspheres (tiny glass or plastic bubbles) added to
emulsion to increase the sensitivity

17. AN/FO-Blasting Prills

18. AN/FO-Blasting Prills
 Agricultural Grade AN-Prill
 High Bulk Density: 0.95 g/cm3 to 1.10 g/cm3
 Low Oil Absorbency: 2% or less
 May contain High Amount of Coatings
 Industrial (porous) AN-Prill
 Lower Bulk Density: 0.80 g/cm3 to 0.90 g/cm3
 Higher Oil Absorbency: 6% Minimum
 Low Coating Content: 1% Maximum

19. AN/FO
Mixture of
Ammonium Nitrate (NH4
+
NO3
-)
and
Fuel Oil (CnHm)

20. AN/FO
 #1 product used today in the blasting industry
 Factors to consider
 Cost
 Safety
 Performance
 (Temperature Cycling)
 (Water Resistance)

21. AN/FO
Velocity of Detonation (VoD) versus Fuel Content
AN/FO at 0.85 g/cm3 and 6” confined
VOD
[ft/s]
Fuel Content [%]
16000
14000
12000
10000
8000
6000
0 2 4 6 8

22. AN/FO
 Amount of Fuel Oil will affect
 Energy
 Velocity
 Sensitivity
 Production of Fumes
 Density (in hole)
 Bulk Loaded 0.82 to 0.92 [g/cc]
 Pneumatically loaded 0.90-1.00 [g/cc]
 Sensitivity declines rapidly after 1.2 [g/cc]

23. AN/FO
Density [g/cm3]
VOD
[ft/s]
20000
15000
10000
5000
0
0.6 0.8 1.0 1.2 1.4 1.6
Velocity of Detonation (VoD) versus Density

24. Blends
 A mixture of (a) an emulsion explosive and
ammonium nitrate or AN/FO; or (b) a
watergel/slurry explosive and ammonium
nitrate or AN/FO.

25. Blends
 Three Main Purposes
 Increase the density of AN/FO; also
increasing the energy within the hole
 Provide water resistance to AN/FO
 Reduce Mining Costs

26. Boosters
 With the development of AN/FO, Water Gels
and Emulsions came the need for a high
pressure booster
 Basic need for a booster 2 x the detonation
pressure of explosive being used
 Two Common Boosters
 NG Boosters
 Cast Boosters

27. Boosters
 NG
 Gelled product
 Higher than 60% strength

28. Boosters
 Cast
 Typically boosters that contain the high explosive
trinitrotoluene (TNT) as the casting material.
 Molecular explosives added to TNT
 PETN (pentolite high % PETN formulation)
 Comp B
 Torpex
 Amatol/Sodatol
 Tetryl or Tetrytol

29. Two-Component Explosives
 Usually consist of a solid and a liquid added at
the time of use.
 Used primarily for small construction and utility
work as there are less stringent storage and
transportation requirements.
 Properties
 Density 1.20 g/cc
 VOD 18,000-20,000 fps
 Detonator sensitive
 Fume class 1
 Water resistance excellent while in container

30. Questions?