At the Fulton Hogan Stonemaster Quarry, south of Brisbane, history has been made. The combined vision of Michael Hazell, the quarry’s divisional manager, Robert Hemming, the quarry operations manager of Fulton Hogan, Dan Donnelly, the operations manager for Donnelly Blasting Services, and Steve Franklin, the principal consultant for Cement & Aggregate Consulting, has resulted in exactly that level of improvement.
How? Through implementation of an integrated service consisting of drone survey, quarry design, scheduling and development planning, machine control and site-based GPS survey – an Australian quarry first.
“Fulton Hogan operates two quarries in the Brisbane/Gold Coast corridor and both quarries have geological and geotechnical challenges,” Hazell said. “Blue Rock Quarry has a very complicated geology, coupled with new development works that need to be carefully managed, so that future production is not constrained by limited supply of higher grade raw feed.
“Stonemaster Quarry, on the other hand, is in the twilight of its life and requires careful management to ensure remaining reserves can be predicted and safely extracted, while providing an engineered design that benefits the user after extraction.”
New way forward
A decision was made to focus on the challenges at Stonemaster Quarry first. With the site a prime opportunity for land re-use as a waste facility, it was important to know how much rock remained and what could be done to create a void that would meet the needs of a potential landfill operator. The key requirements identified from initial discussions with Cement & Aggregate Consulting were as follows:
A cost-effective, accurate survey of the site.
A well thought through quarry plan that considered all the factors for safe and effective operation, including geological, geotechnical, environmental and operational considerations.
A schedule showing what material will be available at what time and in what quantity, and accurately identified quarry development requirements.
A quarterly, rolling plan to ensure there was a clear indication of who needs to do what and when.
Based on Hazell’s requirements, it was decided to create a service that quarries traditionally have not had access to. This would not be an internal quarry resource team producing life of quarry concept plans, or a traditional consulting company carrying out approval, permit and design project work. It would be an “outsourced technical services department” that complemented existing internal and external providers and helped extend their work operationally on an ongoing basis.
The team also realised the site couldn’t wear a large upfront cost to build up the design and schedules. Its approach was to provide an end to end service for a monthly retainer that was within the cost constraints of the operation, provided the ongoing support and advice was affordable and there was a single point of contact.
Survey, design, scheduling
Flying the site with drones and using the resultant photogrammetry to provide inputs for quarry planning resolved the requirement for a cost-effective, accurate survey.
Despite significant advances in this area, there was a lot to learn about safe, CASA-compliant flight planning and ground control point layout for a good result. It wasn’t quite as simple as it initially appeared!
The cloud-based platform proved to be a valuable visualisation and short-term planning tool. It was being used for stockpile management, as well as providing an up to date aerial photograph and point cloud information that fed into the planning process.
After an extensive literature review and geological and geotechnical study, a life of quarry design was created with Deswik. CAD, the latest generation of quarry design software.
It provides a range of innovative functions and its support services were the best the outsourced technical department had ever experienced. It was a key success factor in the final outcome.
The stakeholders reviewed the design to ensure all parties could provide their insights into what was required. An immediate benefit from this was the identification by site supervisor Darren Crawford of an opportunity to refine the design, resulting in a further 13 per cent of high quality aggregate material.
With a robust quarry design in place, Deswik scheduling tools were applied to create a quarterly and life of quarry schedule.
Deswik OPSTS was chosen as a short-term scheduling package. This is an integrated module within Deswik.CAD and creates fast, simple schedules that consider not only load and haul, but also all preparatory steps such as clean-up, drill and blast.
Deswik.Sched was used to create the life of quarry schedule. After setting up the mining rules, resources, materials and product yields, “what if” scenarios were run to determine the feasibility of different production scenarios.
As an example of the scheduling model’s use, Hazell asked the team how much material could be supplied under a potential long-term supply contract and what the likely stripping requirements would be.
Within a few hours, the team created five scenarios to test and determine the best way forward.
“As the manager responsible for overall sustainability of the quarry business I am able to predict what stripping campaigns are required and give prediction to corporate office of any upcoming requirements to stripping or changes to stripping amortisation,” Hazell said.
“We can minimise the expense of pit development by understanding upcoming problems and work with customers to find alternative solutions before my hand is forced to paddock dump material, something I can ill afford with limited room available.”
With the design and schedule in place, concentration turned to getting a rolling quarterly plan enacted.
The purpose of this plan is to ensure all key stakeholders know what has to be done and at what time. This plan incorporates safety, environmental, geotechnical, geological and quarry planning aspects to provide a whole of quarry quarterly development plan (QDP).
One of the challenges in creating the QDP was to ensure sufficient direction and options were available to provide enough flexibility to deal with the many variables that can occur in operations, eg changing customer requirements, weather, breakdowns, etc.
This process more than any other served to bring the stakeholders together each quarter, to work through all the issues necessary to devise a plan that was not only accurate but practical and adaptable to change.
Driving this process on the ground was Hemming, the site’s SSE and operations manager, who worked to bring it to life.
“This process allows me to have a clear view of the direction we are heading and the route to take to get there,” Hemming said. “It allows us to think and act long term, not short term, and provides traceability of blasts and improved quality outcomes.”
Donnelly said: “There is a uniform approach to the operation of the quarry. All personnel understand the requirements of the quarry from supplying high quality rock to the plant, when stripping is required, and the end of the quarry life uses and requirements.”
Hazell added: “Quarterly quarry design and reviews have resulted in effective collaboration between team members, from the pit excavator operator through to the quarry operations manager and with the drill and blast contractor. Our people are on board and know where they are headed.”
Another part of the QDP was reconciliation of planned movement to actual movement. Using the Deswik.CAD reconciliation tool, a visual representation of how the site had performed during the period was created, highlighting which areas were taken that should have been and which areas were taken that shouldn’t have been, and an overall picture of production.
A further challenge was to develop an integrated system that met the needs of all stakeholders and their respective systems. This led to significant research and trials into how best to turn designs into the specific files needed for survey, machine control and blast design.
Once the QDP system was implemented, the team realised it had missed a key requirement – a ground-based survey was needed to ensure blasts were placed in accordance with design. Failure to do so could result in wall damage and loss of areas deeper in the pit needed for future ramps and berms.
The team also learned that a good design was nothing if the local quarry management and supervision couldn’t visualise it on the ground.
Initially it was thought that external surveyors were needed due to the cost and complexity of running survey equipment. However, based on advice from Position Partners, trials found good results could be obtained from relatively inexpensive Topcon RTK-type GPS survey equipment that relied on a regional correction signal rather than via an expensive base station.
Drill and blast
In late 2017 the drill and blast contract was put out for tender. One of the changes made to the contract was the addition of a sliding scale of pricing based on blast size.
An additional change was the requirement for the drill and blast contractor to provide RTK GPS survey equipment to ensure blasts were laid out in the correct geospatial location.
During the tender process, Donnelly Blasting Services (DBS) strongly embraced the concept of better blast scheduling, planning against design, and survey, ultimately retaining the contract. DBS immediately invested in its own RTK GPS rover, in this case an identical set-up to the one Cement & Aggregate personnel were using, ensuring commonality of equipment and sharing of design data.
“Utilisation of an RTK GPS rover on-site, loaded up with the current design files, enables us to mark out blast from design, mark out final crests and toes and carry out spot checks for quarry management to ensure that we are on the correct path,” Donnelly said. “It also gives us confidence that we are blasting in the correct location and reduces the number of site visits.”
3D Machine control
A benefit of the improved survey was the better level control. Smooth floors and correct grade roads reduce tyre damage, reduce truck cycle time and improve blasting results.
With this in mind, a decision was made to fit a 3D machine control system to the primary loading tool, to further enable the good work that was being done.
A Topcon machine control system was fitted to the Cat 390D excavator and has now been in use for some months. The operator is particularly enthusiastic about the system and is regularly achieving a tolerance of +/-0.1m, ensuring the design vision is realised quickly and accurately.
The system also allows for ad-hoc designs in the field. For example, creating a drop cut ramp at a constant 10 per cent is simple using the system, reducing quarry supervisory input and improving support equipment utilisation.
“Through adoption of mine planning we have successfully overcome pit planning issues and have removed the guesswork out of managing the resource,” Hazell said. “Drill and blast results are optimised through better pit preparation and blast design and the pit generally has a very organised appearance. We expect even better results to come, thanks to machine control allowing the operator to dig to a set floor level and not over-dig the shot, leaving a fractured cap rock zone.”
A cost-effective site survey has been a critical factor in the success of the service and is an area that is being investigated further. Survey equipment that can be bought for a tenth of the cost of more traditional equipment is being trialled and will give local site personnel the ability to easily visualise and check what the quarry design looks like on the ground. They will also be able to pick up points (such as a blast boundary) and send them to the outsourced technical services department.
The genius of this system is that it is cloud-based, and as soon as a user logs in on the controller they can see any new designs created and download them or upload pick-ups they have carried out for the team.
A further benefit will be to ensure site users have instant access to critical design data without any concerns about version control.
Standardised workflows are also being devised, which will ensure any competent user can quickly use the Deswik software (if they choose) and work their way through the normal week to week, quarter to quarter activities, with things such as file naming and formatting, storage, etc all handled consistently and automatically.
The coming months will also see the trialling of Hole Navigation System on the new state of the art silenced Epiroc T40 drill rig that DBS is soon to commission.
The convergence of a range of technologies is making a big impact. Drone surveys provide the inputs for accurate and timely planning. World class design and scheduling software allows for fast turnaround of accurate designs. High accuracy GPS survey equipment and machine control ensure that what is designed becomes reality.
Production in May 2018 was up 28 per cent over the monthly target and the highest on record, despite detailed work on ramps and benches – a tremendous credit to everyone on the site.
A recent reckoning was that, due to better scheduling, the average blast size had trebled since the service was started and the savings resulting from this factor alone had paid for it.
Figuring in the reduction in oversize, reduced maintenance costs and productivity improvements would suggest this approach has a substantial initial and continuing ROI.
A further benefit has been a significant reduction in the amount of management time required to control the operation, freeing them up for other activities.
Donnelly summed up his experience over the past 12 months.
“We are seeing better utilisation of our drill rigs and key staff, and planned maintenance occurs when it is planned because we know what production requirements are in advance,” he said.
“Utilisation of loading tool machine control ensures that the correct floor heights are dug to, ensuring that sub-drill is left behind, and we have flat floors to safely drill from.”
Hemming said: “We used to run things day to day. Now we can look out into the future, saving ourselves valuable time and improving the quality of the work and our products”.
Hazell concluded: “To cap it off, I am seeing better productivity through the plant. Better blast results, better haul road design, better planning and more engaged staff have literally given our Stonemaster Quarry a 20 per cent lift in productivity.”
Is 20 per cent better productivity possible? This case study proves it is. It could also be just the start of a range of digital initiatives that will see this site and other early adopters of this service make continued and significant strides towards getting the most out of their resources.
Some examples of this include advanced drone analytic services, quarry design optimisation and integration of the scheduling system with stockpile logistics management and sales optimisation software from Trimble and KillerBee.
The technological advances of the past 12 months brought into a unified whole really do bring about the goal of a “digital quarry”.