FLYROCK Flyrock is the propelling rock from the blast area. Leading cause of fatalities and equipment damage

CORRECTION OF IDENTIFIED CAUSES CAN SOLVE FLYROCK PROBLEMS

FLYROCKS OCCUR WHERE ENERGY IS VENTED INTO ATMOSPHERE AND PROPELS ROCKS WHERE BURDEN AND STEMMING IS TOO SMALL OR HOLES ARE INITIATED OUT OF SEQUENCE DRILLING INACCURACY OVERCHARGING GEOLOGICAL CONDITIONS SYMPATHETIC DETONATION

COLLARING TOO NEAR TOP OF THE FACE IN HIGH BENCH OR HIGHLY INCLINED FACE

LARGE BURDEN & TOP PRIMING CAUSES FLYROCK

GEOLOGICAL CONDITIONS Open joints, mud seams and cavities may result in escape of gases and also blasting nuisances.

DRILLING INACCURACY CAUSES INSUFFICIENT BURDEN RESULTING IN FLYROCK

REMOVAL OF TOE USING SHORTHOLES CAN CAUSE EXCESSIVE FLYROCK

FAULTY DELAY TIMING AND INITIATION SEQUENCE

Re-enactment of where the operator's body was found after the accident

MEASURES TO CONTROL FLYROCK DAMAGE 1.Proper blast design 2.Bench height, borehole diameter, hole inclination, burden and spacing, charge distribution in holes, stemming, initiation sequence and timing 3.Site control during blasting 4.More experienced drilling/blasting crew 5.More effective communication 6.Covering 7.Miscellaneous measures loose stone, toe holes

SAFETY IN FLYROCK Flyrock can still be generated even in the best-designed blast Good blast design is the primary method for avoiding flyrock but good design cannot completely eliminate it. For Reducing Flyrock 1.Use a measuring tape to layout all blastholes. 2. Ensure all holes have proper burdens and spacings. 3. Measure all blastholes before during and after loading. 4. Alert Blaster-in-Charge of overloaded holes, mud seams, cavities, etc. 5. Use millisecond-blasting techniques. 6.Use proper explosives and blast geometry 7.Design appropriate initiation sequence. 8. Use blasting mats. 9. Maintain adequate distance when initiating and observing blasts. Also, have adequate protection if needed. Under vehicle, blasters boxes, etc.

COVERING WITH WIRE NET

PROPER STEMMING TO CONTROL FLYROCK