In both the mining and construction industries, blasting is the predominant method for fragmentation of consolidated mineral deposits and rocks. The public relation problems of users of explosive...
Summary of blasting theory
DRILLING ,BLASTING AND FRAGMENTATION OF ROCKS 1:Factors affecting drill pattern i:geology ii: area shape iii:free faces-location and nos iv:boreholes-dimensions v :explosives-types and characterist...
In both the mining and construction industries, blasting is the predominant method for fragmentation of consolidated mineral deposits and rocks. The public relation problems of users of explosive...
opration of blasting of boreholes
Deciding how you to know Blasting Index in coal mining industry.Deskripsi lengkap
Peledakan batu kapur di PT Semen Batu Raja. Pengaruh energi peldakan terhadap fragmentasi
Abrasive blastingFull description
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In both the mining and construction industries, blasting is the predominant method for fragmentation of consolidated mineral deposits and rocks. The public relation problems of users of explosive...
In both the mining and construction industries, blasting is the predominant method for fragmentation of consolidated mineral deposits and rocks. The public relation problems of users of explosive...
Full description
The measure of effectiveness of drilling and blasting operations is not in terms of blasting cost alone, but rather by its contribution of the efficiency and economy of total excavation system. Sav...
Description : Fragmentation Principles Factors Affecting Fragment size How To quantify the fragmentation Calculation of Fragmentation
Face Height ........................................................................................................... 9 Hole-to-Hole Delay Time .......................................................................................... 9 Loading Density .................................................................................................... 10 Maximum Charge Weight per Delay .......................................................................... 10 Minimum Distance.................................................................................................. 10 Powder Factor ...................................................................................................... 10 -Volume of Rock Input -Weight of Rock Input
Pre-Splitting Formulas for Air-Decked Charges .......................................................... 11 -Spacing of Air-Decked Charges -Weight of Air-Decked Charges -Stemming Column Length
Pre-Splitting Formulas for De-Coupled Charges ......................................................... 11 -Linear Charge Weight -Spacing between Pre-Split Holes
Pressure Formula .................................................................................................. 11 Relative Weight Strength (RWS) ............................................................................... 12 Resistance Formulas ............................................................................................. 12 -For Paralle Circuits -For Series Circuits
Row-to-Row Delay Time ......................................................................................... 12 Stone Stemming Particle Size .................................................................................. 12 Spacing ............................................................................................................... 13 -Instant -Delayed
Sub-Drilling .......................................................................................................... “Supersonic” Face Velocity ..................................................................................... Top-Stemming Length ........................................................................................... Water Displacement .............................................................................................. Weight of Rock per Blast Hole ................................................................................. Vibration Level Prediction .......................................................................................
13 13 13 14 14 14
-Peak Particle Velocity Prediction -Site Specific Ground Transmission Constant
Volume of Rock per Blast Hole ................................................................................ 14
Variables used in formula and required units in [brackets]. If input variables are not in required units, then you must use the unit conversion tables.
Absolute Bulk Strength (ABS)
ABS E � AWSE � dE
Base-Charge Length Formula
Eb �
�� 0.3
VARIABLES and [UNITS]
E b = Length of base charge of high density explosives [ft] B = Average burden [ft] J = Sub-drilling depth [ft]
Acutual Scaled Distance Formula
Actual Scaled Distance
VARIABLES and [UNITS]
ABS E = Absolute bulk strength of the explosive [cal/cc] AWS E = Absolute weight strength of the explosive [cal/g] d E = Density of the explosive [g/cm 3 ]
Sub-Drilling Formula Spacing Formulas J � � 0.2 � 0.5 � � B If: VARIABLES and [UNITS]
B = Burden [ft] J = Sub-drilling [ft]
H �4 B
If:
Instant
S � 2.0 � B
S�
Delayed
S � 1.4 � B
S�
H <4 B
H � (2 � B ) 3 H � (7 � B ) 8
VARIABLES and [UNITS]
H = Face height [ft] B = Burden [ft] S = Blast-hole spacing [ft]
Top Stemming Length Formula Industry’s leading Detonating Cord
T � � 0 .7 � 1 .3 � � B "Supersonic" Face Velocity Formula
D min �
S
VARIABLES and [UNITS]
B = Burden [ft] T = Top stemming length [ft]
1.127
VARIABLES and [UNITS]
D min = In order to avoid air-blast from "supersonic" lateral face velocity, the delay between holes must be more than Dmin [ms] S = Spacing between blast holes [ft]
C = Number of explosives cartridges required to rise above standing water L w = Length of the standing water column [ft] L c = Length of one explosives cartridge [ft] D c = Diameter of explosives cartridges [in] D h = Diameter of blast-hole [in]
PPV = Peak particle velocity [in/s] K = Ground transmission constant [K=160 if no other seismic data is available] SD = Scaled distance factor
Site Specific Ground Transmission Constant 1.6 K � PPV � SD
