Optimised rehab build and management

Utilising technology for improved outcomes when a site reaches the end of its life.

Mine site rehabilitation is a critical aspect of sustainable mining practices. In Australia, the ability to demonstrate a proven track record of effective land stewardship is increasingly becoming a minimum qualification for land access consideration.

In 2019, the Australian Government passed new legislation that requires site-specific mines to prepare a progressive rehabilitation and closure plan (PRCP). These must include binding, time-based milestones.

As a key performance indicator of a company's environmental and sustainability practices, early planning and continuous improvement for rehabilitation processes benefits all stakeholders, including companies, governments and communities.

The Australian Government identifies five key stages of effective rehabilitation planning and implementation in its 2016 Mine Rehabilitation Handbook:

Landform design and construction is defined as a core stage of the rehabilitation techniques stage of a project. Optimised landform design and construction results in improved landform stability, the ability to meet or exceed regulatory standards, increased community acceptance, and reduced cost to build.

Australia operates many of the largest mine sites in the world, which makes effective rehabilitation all the more important. Landform construction at scale is a lengthy and costly process where any and all operational improvements result in significantly improved outcomes, lower costs and less rework.

Getting the design and material movement strategies optimised at the outset can lead to significant cost savings for dozer push work. By mathematically simulating the movement of material in the office, budget costs, construction review and scheduling information can be created, evaluated and refined with the aim of reducing or eliminating rework in the field.

According to Position Partners mining executive manager Andrew Granger, in order to fully realise these design benefits, it's essential that they are followed and constructed accurately in the field.

"Complementing an optimised rehab design with high-precision machine guidance technology provides live updates for operators with their exact position relative to design," he said.

"Without the time lag of waiting for as-built survey data, operators can get the work done right the first time, saving on fuel and machine wear in the process."

High-precision machine guidance technology can be leveraged to ensure on-site work is completed to specification, reducing rework and improving accuracy of the rehab build.

Position Partners has successfully deployed high-precision machine guidance on several Australian rehabilitation projects ranging in scale and complexity.

"Our team works collaboratively with third-party design specialists, enabling customers to bring their optimised designs to life through accurate guidance on machines," Granger said.

Machine guidance utilises a combination of high-accuracy global navigation satellite systems (GNSS) to give operators near real-time visualisation of their position relative to design. Sensors mounted to the machine blade provide centimetre-level guidance on distance to grade, with directional push arrows and intermediate surfaces to guide through each stage of the job.

"By moving material as efficiently as possible with minimal rehandling, customers save time and fuel, reduce machine wear, and end up with a more stable and accurate landform," Granger said.

Accurate construction significantly reduces not only build costs, but also maintenance costs. Problems with erosion, berm failures, tunnel erosion and overtopping due to sediment can all be mitigated through accurate material placement and construction during the landform build with machine guidance.

Machine guidance solutions can be fitted to any make or model of machine, Granger said, enabling the same efficiency gains and accuracy benefits on a mixed fleet of equipment.

Throughout the construction process, companies outline their capabilities to support customers with any design change requirements or technical troubleshooting.

"It is not uncommon for in-field conditions to change, requiring modifications to the design due to unexpected material swelling and/or compaction," Granger said.

"Engineers can remotely send design file updates to multiple machines simultaneously, ensuring operators are always working to the current version."

With a large team of technical experts, Position Partners offers remote phone and web-based support, as well as boots-on-the-ground services for machine guidance customers, with coverage in all states and territories.

Managers can have full access to an array of data insights, helping to facilitate proactive project management and strategic planning. Dashboards provide quick, easy-to-read visual reviews of production rates, good and bad production areas, areas and volume of rehandle, and task ratios (pushing:ripping).

"Position Partners can work with clients at all stages of a rehabilitation project, customising technology to suit each site's unique topography, desired outcomes and specifications," Granger said.

"We typically see customers achieve up to 30 per cent savings in earthworks costs through a combination of optimised design that is implemented accurately through the deployment of high-precision machine guidance.

"By getting this critical project phase completed as efficiently and sustainably as possible, sites have a safe, stable landform that is optimised for the next stage and its future use."

This feature appeared in the June 2023 issue of Australian Mining.