This article focuses on innovative methods adopted by an aggregate company to enhance the efficiency of its drilling and blasting operations. The primary objective is to streamline the process, reduce costs associated with both primary and secondary blasting, and ultimately extend the operational life of loading, hauling, and crushing equipment.
Rock drilling marks the initial phase of the mining process, serving as the foundation for all subsequent operations such as blasting, loading, hauling, and crushing. As such, optimizing drilling parameters is essential to minimizing costs in the downstream phases of production.
Effective blast planning must consider several key factors, including the required rock volume for daily, weekly, and monthly production targets, the type of drilling equipment and drill bits available, the size and capacity of haul trucks, the desired fragmentation, and the primary crusher’s feed size constraints.
A critical aspect of executing a safe and cost-efficient blast—free of flyrock and excessive explosive use—is a precise understanding of the free face of the bench. To achieve this, the implementation of advanced technologies such as laser scanning, drone surveys, and inclinometers like O-PitDev is recommended. These tools provide detailed digital models of the rock face, enabling accurate determination of the bench profile, optimal hole orientation and depth, and precise explosive loading adjustments based on actual hole positioning. Ensuring that blast holes are drilled as straight as possible is vital for uniform explosive distribution and minimizing flyrock incidents. The resulting rock fragmentation should align with the capacity of loading and hauling equipment as well as the specifications of the crusher, reducing the need for costly secondary blasting.
Blasting technical considerations
As illustrated in the picture below, the blasting parameters can be deduced from the data supplied by the company’s technical staff.
O-PitDev inclinometer
O-PitDev is a technological tool designed to measure the inclination and azimuth of projected drill holes and compare them with actual values. Using the probe, the drill holes were audited to verify whether the actual depth and inclination aligned with the projected parameters, as illustrated in the image.
The holes showed good results having their deviation value and depth partially projected with the real one, on this occasion already foreseeing to avoid:
- Toe;
- Coarse fragmentation;
- Secondary blasting;
- Vibration;
- Uneven the floor.
Unmanned Aerial Vehicle (Drones)
Drones play a crucial role in both open-pit and underground mining by enhancing safety and providing valuable data on blast areas. They can access hazardous zones unreachable by traditional equipment, helping to protect workers. Using drones like the DJI Phantom 4 Pro, operators can analyze fractures along the free face, inspect blast hole conditions, and record high-quality videos for detailed bench analysis. Their ability to hover enables precise inspections, aiding in risk reduction during detonations and supporting the analysis of flyrock and harmful gas formation.
3D Laser scan and modeling
The Quarryman Pro is a field instrument that uses laser technology for high-speed, automatic scanning of the free face and hole positions. It functions both as a conventional surveying tool and as a total station. In our case, it was used to map the bench, with data exported to O-Pitblast software for 3D modeling (see equipment image ). Following the 3D laser scan and UAV inspection—combined with GPS georeferencing—a geotechnical classification was performed using the Lilly method. The identified holes were then analyzed within the software using the integrated 3D model.
Blasting design and simulation using O-Pitblast software
A rock blast simulator enables the integration of data from various sources, including the Inclinometer, 3D Scanner, UAV, and Seismograph. It allows for rapid blast modeling and seamless sharing with project stakeholders via O-PitCloud. Additionally, it generates detailed reports and supports charge auditing through a dedicated Android application.
Some applicability for this software is:
- Drill pattern design
- Charge and timing simulation
- Fragmentation and vibration prediction
Using O-PitSurface, along with data from the drone and O-PitDev, we analyzed critical profiles in the front row of the working bench. This allowed us to optimize hole inclinations, identify misaligned holes, verify their actual distance from the free face, and accurately determine the necessary explosive charge to control vibration, fragmentation, and flyrock. The images above illustrate two holes and their measured distance from the bench face.
List of References
https://www.o-pitblast.com/blog/application-of-technologies-for-the-optimization-process
https://www.o-pitblast.com/blog/application-of-technologies-for-the-optimisation-process-par
Image Credit: A R Turner/Shutterstock.com from https://www.azomining.com/Article.aspx?ArticleID=1848
