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Client: Lafarge

Project: Worldwide Blasting Optimisation Initiative

Laser System: Quarryman and Boretrak

Lafarge is implementing a worldwide initiative to

optimise drilling and blasting operations across its

600 sites globally. The initiative aims to reduce costs,

increase safety, and lessen the impact on the

environment. The potential savings have been

estimated at 10-25 million Euros annually.

Fragmentation has a large impact on quarry performance at everystage of the drilling, loading, and blasting process. The initiativetherefore plans to increase awareness and understanding offragmentation and implement best practices to reduce direct andindirect costs. Best practices include the identification of experts,suppliers and equipment to improve the blasting process plus settingup procedures and ensuring competency of operators throughtraining.

Principles of Successful Blasting

Blast Design Parameters

The measurement, understanding, and use of accurate designmetrics are very important for successful blasting. This should alsoinclude consultation with mining plans and a good understanding ofthe quarry geology.

Blast Design Pre-requisites

Face preparation Benches must be cleared, scaled of loose rock,and inspected for condition before profiling and blasting.

SurveyingAccurate bench profiling and surveying is the first stage inthe manufacturing process and is critical to the efficiency of theremaining downstream activities. Key to this is the use of correctequipment and trained operators. Measurement of bench heights,level of crest and toe, slope angle, and maximum & minimum burdencan be done using 2D and 3D laser profiling. By mapping a rock facein detail it is possible to determine actual burdens in front of eachplanned borehole to avoid excessive burden (vibration, oversize) andinsufficient burden (flyrock, airblast). If neglected or if surveying isdone incorrectly it can have a detrimental effect on the rest of themanufacturing process including poor quality drilling and miningoperations with increased safety risks and cost.

Blast Design Metrics

Quarry face profiling

3D Face profiling using MDL QuarrymanPro

Blasting Optimisation

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Blast Design

Pattern Design Blast hole layout should be designed with respect tothe collected survey data and hence the accuracy and interpretation ofthis data is paramount. Safety parameters, vibration limits, explosivesto be used, and design floor elevations must also be considered whendesigning the pattern. The resulting blast design plan should clearlyspecify the collar elevations, burden, spacing, drill hole diameter, typeand quantity of explosives and type and delay of detonators. Thelayout of the blast hole pattern should then be set-out through the useof surveying instruments.

Drilling

Execution - Checking that the drilling is done correctly as per the blastdesign is very important including verifying the hole depth, diameterand inclination using accurate blast hole geometry measurementequipment. Incorrect drilling including wrong positioning, incorrectangle, hole deviation, and incorrect depth can pose serious risks.

Explosives

Loading Plan Effective implementation and validation of the loadingplan including the position of delays, charge, charge distribution, type

& quantity of explosives, and stemming requirements.

Conclusion

The improvements gained from an optimised drilling and blastingoperation can be measured by reduced costs per tonne for blastingand drilling, improved loading speeds, reduced oversize breakage andhandling, reduced energy consumption and less fines.

The average measured saving from the pilot study across 12 sites isabout 4 Euro cents per tonne. Across Lafarges total aggregate andcement mined tonnes (250Mt) this equates to a 10 million Eurosavings annually. Lafarge is confident that further savings can bemade through a rigorous optimization process and is currently rollingout the system across the group.

X.Thrin VP Land, Minerals & Mining

Blasting Optimisation

Incorrect drilling execution

Borehole geometry survey using MDL Boretrak