This document provides an overview of blasting and explosives used in mining. It discusses blasting accessories like detonators and initiating systems that can be electric or non-electric. The properties of explosives that impact fragmentation, displacement and vibrations are outlined. Electric detonators utilize electric energy to heat a connecting bridge wire, while electronic detonators use a microchip. Non-electric systems transmit initiation through plastic tubing. Common blasting patterns like row-by-row and V-formation are also mentioned.

3. CONTENT
• INTRODUCTION
• BLASTING ACCESSORIES
• PROPERTIES OF EXPLOSIVE
• INITIATING SYSTEM
• ELECTRIC DETONATORS
• NON ELECTRIC SYSTEM
• INITIATING BLASTING PATTERN
• REFERENCES

4. INTRODUCTION
THE PROCESS OF BREAKING ROCKS INTO SMALLER PIECES BY USE
OF EXPLOSIVES.
EXPLOSIVES IS A CHEMICAL COMPOUND OR MIXTURE, WHEN
EXPLODED BY ACTION OF HEAT, IMPACT, GIVES LARGE VOLUME OF
GASES IN A VERY SHORT TIME AT HIGH TEMPERATURE & PRESSURE.
• THE TYPES OF EXPLOSION ARE THE FOLLOWING:
MECHANICAL
ELECTRIC
NUCLEAR
CHEMICAL, FROM THE MINING POINT OF VIEW, ONLY THE
LAST ARE OF INTEREST

5. BLASTING ACCESSORIES
• VARIOUS IMPORTANT BLASTING ACCESSORIES ARE AS UNDER:
1. SAFETY FUSE
2. PLASTIC IGNITOR CORD.
3. DETONATORS.
4. CORD RELAY
5. DETONATING CORD
7. ANODET
8. OHM METER
9. EXPLODER

6. PROPERTIES OF EXPLOSIVE
• THE PROPERTIES OF EACH GROUP OF EXPLOSIVES GIVE PREDICTION OF THE
PROBABLE RESULTS OF FRAGMENTATION, DIS-PLACEMENT AND VIBRATIONS.
THE MOST IMPORTANT CHARACTERISTICS ARE:
• STRENGTH AND ENERGY DEVELOPED
• DETONATION VELOCITY
• DENSITY
• DETONATION PRESSURE
• WATER RESISTANCE
• SENSITIVITY
OTHER PROPERTIES WHICH AFFECT THEIR USE AND MUST BE TAKEN INTO
ACCOUNT ARE:
FUMES, RESISTANCE TO HIGH AND LOW TEMPERATURES, DE-SENSITIZATION BY
EXTERNAL CAUSES, ETC.

7. INITIATING SYSTEM
Electrical system
detonator of priming, only
electrical wires are attached.
Non-electric system
there is no electric wire
is required in the hole.
D-cord or detonating fuse
Instantaneous electric
detonators
Short delay detonators
(millisecond delay)
Long delay detonators
(half second delay)

8. ELECTRIC DETONATORS
• ELECTRIC DETONATORS ARE USED TO INITIATE
OTHER EXPLOSIVE, DETONATING CORD AND SHOCK
TUBE
• IN ELECTRIC DETONATORS ELECTRIC ENERGY IS
SENT THROUGH COPPER LEG WIRE TO HEAT AN
INTERNAL CONNECTING BRIDGE WIRE.
• ELECTRONIC DETONATOR HAVE AN ELECTRONIC
COUNTER ON A MICROCHIP IN PLACE OF
PYROTECHNIC DELAY CHARGE.

9. ELECTRONIC DETONATORS
• ADVANTAGES:
HIGHER TIMING PRECISION (10 MICROSECOND
THAN 1-10 MS SCATTER)
INCREASE CONTROL TIME DELAY
GREATER SAFETY AGAINST ACCIDENTAL IGNITION
(CODED FIRING SIGNALS)
• DISADVANTAGES
HIGHER PRICE BECAUSE OF CHIP AND CAPACITOR
BACK TO ELECTRIC WIRING-RISK OF GROUND
FAULTS OR POOR CONTACTS

10. NON ELECTRIC SYSTEM
• NON-ELECTRIC INITIATION SYSTEMS INCLUDE A
CAP SIMILAR TO THAT OF AN ELECTRIC CAP, BUT
THEY ARE CONNECTED TO PLASTIC TUBING OR
A TRANSMISSION LINE THAT CARRIES AN
INITIATION (SHOCK AND HEAT) TO INITIATE THE
CAP.
• NOT USED IN UNDERGROUND COAL OR GASSY
MINES.
• PROVIDE NEARLY INFINITE NUMBERS OF
DELAYS IN BLASTING PATTERNS.
• DELAYS ARE AVAILABLE IN SHORT AND LONG
PERIODS AS WELLAS IN-HOLE AND SURFACE
DELAYS.

11. ADVANTAGES
ABILITY TO DESIGN BLASTS WITH A GREATER NUMBER OF HOLES THAN
TRADITIONAL ELECTRIC BLASTING.
DANGER OF STRAY CURRENTS ARE ELIMINATED WITH THE USE OF NON-
ELECTRIC SYSTEMS.
NON ELECTRIC SYSTEM

12. INITIATING BLASTING PATTERN
• ROW BY ROW PATTERN
• FIRING PATTERN
• V-FORMATION FIRING
PATTERN
• DIAMOND FIRING PATTERN

13. REFERENCES
• http://www.slideshare.net/yghule/drilling-and-blasting-powerpoint-2003?qid=1c433782-5895-4db0-
81a0-73674f50f9c4&v=qf1&b=&from_search=1
• http://www.slideshare.net/smhhs/explosives-andblasting?qid=1c433782-5895-4db0-81a0-
73674f50f9c4&v=qf1&b=&from_search=8
• http://en.wikipedia.org/wiki/Rock_blasting

14. THANKYOU