Explosives manufacturer Orica has reported more precise and safer underground ore blastig results with its increasingly automated WebGen blasting system.
The Melbourne company said Nexa Resources (Nexa Vazante) had been able to improve safety and ore recovery with a single WebGen blast at its Brazilian mine.
The fully wireless blast initiation system significantly reduced ore dilution by waste material from 27 per cent to 20 pr cent, resulting in a net benefit of US$1.59 million.
The system achieved a smaller hydraulic radius by keeping an underground pillar during the extraction of ore from the mine, creating an open stope.
The pillar was also pre-loaded with the initiators, and was detonated in a later blast without the need for staff to re-enter the stope.
This in turn resulted in a reduced cycle time to 20 days, down from an expected 90 days by maintaining two mucking access points to the main stope.
Nexa Vazante Chief Mining Engineer Mateus Ribeiro said: “We went through a series of improvements in the evolution of blasting technology with Orica, from the first detonators until nowadays using 100 per cent wireless detonators.
“The blast happened two levels below us, so we are 400 metres away, above the shot.
“All encoded signals were sent through the rock with the safety protocols to fire the blast being followed.”
Nexa Vazante, a zinc and lead mine owned by Nexa Resources, is located in northwest Minas Gerais, Brazil.
The mine has traditionally deployed wired initiators in the recovery of ore, typically yielding around 60 per cent ore recovery in the pillars.
Orica’s Latin America Wireless and Electronic Blasting Systems Specialist, Wesley Andrade said: “This achievement in recovering a pillar through wireless initiation while protecting people from hazards is made possible only by the strong partnership between Nexa Vazante and Orica.”
The pillar pre-loaded with the wireless initiators were safely fired after 33 days of sleep time, with several ore blasts taking place alongside the pre-loaded pillar.
Picture: Orica/WebGen uses low frequency magnetic induction signals to transmit firing commands
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