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ISMR Technology Transfer Seminar

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Presentation on theme: "ISMR Technology Transfer Seminar"— Presentation transcript:

1 ISMR Technology Transfer Seminar
ANFO & Emulsion Characteristics Heavy Blends as a Tool for Blasters!

2 What is needed for an explosion?

3 ANFO Ammonium Nitrate / Fuel Oil Ammonium Nitrate Production
Reaction of anhydrous ammonia gas and concentrated nitric acid. After the reaction the AN solution is about 83% concentration. Excess water is evaporated off to leave an AN concentration of 95 to 99.9%.

4 AN Production cont’d AN Solution is turned into prill.
A small percentage of water is left in the solution when the prill is formed. When the prill is dried the water is removed and it leaves voids in the prill. This is where the diesel fuel goes when added to the prill.

5 ANFO Characteristics ANFO Density ranges from .82 - .90 g/cc
Oxygen 94.4% AN / 5.6% Fuel Under fueling leads to: Greater sensitivity. Drastic loss of ENERGY! Orange smoke, inefficient reaction during detonation. Over fueling leads to: Loss of Energy.

6 Effects of Fueling on Fume Production

7 Effects of Fueling on Fume Production

8 Effects of Fueling on Energy Output

9 ANFO and VOD ANFO VOD increases as the borehole diameter increases.

10 ANFO Characteristics The critical diameter of poured ANFO is about 2.0 – 2.5 inches. Under this it will not detonate. If it is loaded pneumatically the critical diameter can be increased to 1.0 inch. ANFO is considered a ‘Blasting Agent” This means it cannot be detonated with a #8 strength detonator when unconfined. It requires a primer assembly to be initiated.

11 ANFO Characteristics When ANFO detonates it does so inefficiently.
This produces excess gases from the reaction. This is a benefit to blasting due to the rapid expansion of the gases out into the formation creating a “heave” effect. This heave effect allows for easier digging.

12 ANFO Characteristics ANFO is not waterproof or even resistant.
ANFO can deflagrate if a significant amount of water has damaged the ANFO. ANFO can fail to detonate if water has damaged enough ANFO in the hole. If the ANFO shoots “low order”, it shoots inefficiently and produces excess gases. Orange fumes!

13 Emulsion Water solutions of oxidizers in an oil medium. (ISEE Blasters Handbook: Chapter 7, page 77.) A mixture of two or more liquids in which one is present as droplets, of microscopic size, distributed throughout the other.

14 Explosive Emulsion Anatomy
Oil continuous, “external” phase (green) – 5 to 9% Mineral oils Diesel fuels Recycled oils Vegetable oils Aqueous salt discontinuous, “internal” phase (blue) – 91 to 95% Ammonium Nitrate Calcium Nitrate Sodium Nitrate Perchlorates

15 Bulk Emulsion Characteristics
Typical density of a sensitized emulsion runs about 1.25 g/cc. Loaded in diameters between 1and 12 inches. VOD increases with Borehole Diameter. Sensitivity/density can vary with the addition of microballoons or chemical gassification. Can be dead pressed when sensitized with microballoons. (Crushing of balloons) Can be classified as Oxidizer of Blasting Agent.

16 What are Heavy Blends? Blends of ANFO and Emulsion

17 Heavy ANFO Blends Why utilize blends?
Increase the density of ANFO; hence, increase energy in the borehole Provide water resistance to ANFO Reduce mining costs (ISEE Blasters’ Handbook; Chapter 9, page 93.)

18 Heavy ANFO Blends

19 Emulsion/Blend Properties

20 Emulsion/Blend Properties

21 Generic Cost Comparison

22 Blend Benefits Longer sleep times with heavy blends.
Water resistance for ANFO in wet formations. Pattern expansions. Maximize energy in hole. Drill cost savings potential. More production yards per hole. Less shots per cut.

23 ANFO Shot

24 Gassed Emulsion

25 Gassed Emulsion

26 Blend Shot

27 Blend Shot

28 Blend Shot

29 Blend Shot

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