Case Studies

The project aim was to evaluate how current blasting practices influenced pit wall stability as a number of failures had occurred throughout the pit, with a focus on wall control blasting techniques and vibration management. A comprehensive review of monitoring data, current final wall blasting techniques and mine survey information identified issues in both vibration data and blast execution protocols.

A detailed on-site mine audit and desktop study helped identify areas for improvement in blasting practices and data collection. A modified test blast programme showed improvements in wall preservation, validating the need for improved ongoing controlled blasting techniques tailored by geotechnical and geological zone.

Using site specific information, the mine required blasting parameters to accurately establish blasting costs to feed into the pre-production feasibility study. Utilising rock properties established from testing, fragmentation requirements of crushing circuits and environmental control requirements accurate blast designs were produced for a number of mining scenarios. In-depth fragmentation modelling was carried out alongside cost analysis to produce optimal designs by geological zone and commodity.  

Hedardh were engaged to carried out a mine site study to reduce blast induced ore loss and dilution within a complex orebody in an open pit gold and silver deposit. The on-site study included time spent with all mining departments and drill & blast crew to fully understand current practices and challenges. Clear and operationally practical improvements where highlighted, supported with site-based assistance including improved processes, training and blast movement control techniques to reduce both ore loss and dilution.

Due to mine expansion a bridge construction was required to access new reserves, this required piling installations and abutments constructed using reinforced concrete. A pre-construction desktop study was undertaken to establish likely peak particle velocities and frequencies which may cause structural damage. This study was used to schedule blasting and mine production in this area. Upon commencement of mining operations on-site blast vibration monitoring was carried out to establish site-specific vibration characteristics, including frequency analysis, to provide greater damage risk reduction.

A drill and blast audit was carried out at an open pit coal mine in Asia. All processes were reviewed on-site including drilling operations, blast crew loading and an in-depth review of site procedures. Following the audit it was necessary to produce new procedures for all drill and blast operations at the mine along with design protocols to improve the mines safety, productively and cost efficiencies.