Optimising the sprayed concrete process via the holistic portfolio, to improve from batching to spraying.
Contractor
Kirkland Lake Gold
Processes
Sprayed ConcreteLocation
Australia
CLIENT ISSUE
Normet have been proactive in supporting Fosterville Gold Mine to lower the accelerator dosage level and shorten the re-entry times, reaching 1 MPa in under an hour. As a target identified by Normet, the mine would benefit greatly from the Normet product offerings within the construction chemicals and rock reinforcement, equipment and services business lines. The mines overall sprayed concrete performance was inconsistent, various sprayed concrete OEM’s being used throughout the concrete delivery/spraying process and further training required for nozzleman.
Fosterville Gold Mine
THE CHALLENGE
The overall ‘challenge’ was to introduce the holistic Normet portfolio of product offerings into the mine and show/prove the value this partnership has for the mine operators. After presenting our value proposition, the client engaged Normet to perform a sprayed concrete audit and review the mines overall sprayed concrete process from batching to spraying. Processes needed to be refined through the education of batchers of the importance of performing moisture content measurements, understanding of water/cement ratio and its effect on the re-entry times, the importance of performing slump tests and calibrating the admixtures dosing system. Nozzleman training to reinforce spraying principals and educate how to identify shotcrete thickness on the wall, the role the slump testing and equipment have in creating more homogenies concrete, along with the introduction of TamShot 110AF, the next generation alkali free set accelerator.
Fosterville Gold Mine - Spraying Trials
THE SOLUTION
The solution began with building the customers knowledge on the TamShot 110AF Alkali Free set accelerator, this was to establish the benefits of using the Normet’s chemical over others, such as dosage reduction and earlier re-entry times. We performed sprayed concrete chemical trials over the period of one month with site support offered over this period. Results were very positive over re-entry, 3 day, 7 day and 28 day strength gains. Next stage was mix design enhancements using the TamCem 66 and TamCem HCA with adjustments on water cement ratio and slump retention. Pre-trials was conducted off site followed by a month long trials onsite with site support in the batching process. Once again, the mix design achieved the desired outcome.
Fosterville Gold Mine - Mix design enhancement
Upgrades to the Normet equipment included 2 x Spraymec SF 050, 2 x Spraymec MF 050 (1000 volt) and 3 x Utimec LF 700 Agitators was made and delivered to site, providing increased load capacity and low pulsation concrete pumping for more consistent and homogenized concrete spraying.
Nozzleman training was identify as a small step forward, which would create a big difference in the overall outcome of the spray process. The training was perform over a period of visits to the mine from the Normet Spraymaster Trainer.
Project Outcome
Over this implementation period, there was numerous benefits to the mine directly, including:
- Shorter re-entry times creating an opportunity for the Jumbos to enter earlier
- Safer ground conditions due to the knowledge gained for the nozzlemen to achieve efficient spraying
- Less tramming requirements as more consistent concrete mixes was produced at the batch plant
- Less rejected concrete loads due to the batch plant operators understanding the importance of their role in the ground support process in the complex area of concrete technologies.
EFNARC certification has been provided to a number of nozzleman via our Normet Spraymaster and experts, the mine now has one of the largest teams of EFNARC certified nozzleman in the country.
Normet’s product offerings and support, proving their value to the mine, and demonstrating what key partnerships can produce when capable mine operators work hand in hand with an OEM for chemical, equipment and service support.
