Fifth International Conference on Block and Sublevel Caving
30 August – 1 September 2022 | Hilton Adelaide, South Australia
Ryan has 20 years of geomechanics experience specialising in mass mining project development, strategic planning and operational support. After being stationed at the Grasberg operation, Ryan returned to work within PT Freeport Indonesia’s corporate geotechnical group. Prior to Freeport, he worked with SRK Consulting where experience was gained in open pit and underground mass mining operations in Canada and abroad. Recent areas of focus at Freeport include optimisation of cave and development sequencing, rock mass characterisation, excavation design, ground control, open pit/underground interaction, fragmentation forecasting and risk management.
How companies operate caving mines can differ, often extensively, from what was originally envisioned during planning stages. Realities change as the project shifts from a paper design through construction, the first encounter with actual conditions, to cave establishment and steady state production. Much is learned along the way, including how an organisation functions (and responds to change), how the rock mass itself responds to caving, the robustness of the original plan to actual conditions and whether the cost and schedule estimates were reasonable or achievable. Once a mine is operational, strategy and tactics continue to evolve from initial plans as changes are made to deal with the realities of ground conditions, project logistics and market pressures. Invariably, such changes tend to result in schedule delays and cost increases. The intent of risk analysis is to capture the likelihood and consequence of such changes and to have mitigation processes in place to deal with the new conditions. As a planning and operational necessity, risk management at larger operations is typically established and maintained to at least a basic level. However, the systematic capture and application of lessons learned and opportunities (i.e. the feedback loop), tends to be less formally implemented. Critical institutional knowledge can be lost with staff departures or poor records capture. Case examples are provided to illustrate the benefits of risk, lessons learned and opportunity registries across multiple disciplines in large panel caves. Experience is shared on the linked utilisation of these tools, which has led to stronger organisational collaboration with more desirable safety and production outcomes. Differing vantage points from consulting, corporate and mine operations roles are explored based on personal experience.
Corporate Consultant (Mining)
Simon has over 35 years’ international experience including the development and operation of block cave mines and operating open pit mines above caving zones. Simon has led projects across the whole resources value chain: all study phases, project implementation, construction and commissioning, and mine operations. Mine management and construction experience was gained in South Africa, Australia, and the USA in gold, coal, base metals, copper, platinum, industrial minerals, and diamonds. Since joining SRK in 2010, Simon has worked globally in project management, due diligence, and technical reviews for surface and underground mining projects, and lender construction oversight for development projects. His commodity experience also includes iron ore, lithium, graphite, nickel, bauxite, manganese, niobium, tungsten, potash brines, and mineral sands projects.
Established natural caving (i.e. block or panel caves) projects and operations have been underway for decades and are clearly visible. In recent years, a number of new caving projects have been under study. These projects are typically new discoveries or surface to underground transitions, with ownership outside of the existing mainstream cavers. The new projects do not typically have the benefit of deep in-house caving skills and rely on study teams that assemble a number of entities to investigate the various required study components. A key challenge for project owners is initially the quantum of finance that is required to source all the required orebody knowledge and carry out suitable investigations. In most cases, this is a serious challenge and drives the observed behaviours and outcomes. This paper focuses on the required workflow for natural caving projects from scoping study to about a pre-feasibility study level; in contrast to detailed design aspects that are discussed elsewhere in this conference.
Pedro Landeros Córdova
Director of Geotechnical Engineering, El Teniente Portfolio of Projects
Pedro has over 15 years’ experience in underground geotechnical and geomechanical engineering. From 2008 to 2016, he worked as a geomechanical engineer at the El Teniente mine for the Esmeralda and Reservas Norte operating sectors and then for Dacita and Recursos Norte Projects.
Since 2016, Pedro has led teams of geologists and geomechanics for El Teniente future expansion projects. He is currently the director of geotechnical engineering of the El Teniente Portfolio of Projects, leading geotechnical ground control of Andes Norte, Andesita and Diamante projects.
His main experience and expertise relate to caving geomechanics and underground geomechanical risk management, mine-induced seismicity, rockbursts, hydraulic fracturing, and excavation design in high-stress environments with complex geomechanical conditions.
El Teniente Mine expansion plans are currently under development and construction stages through an integrated project strategy that will allow the continuity of future mining. The deepest sector corresponds to Andes Norte Project, which has the additional mission of generating new knowledge and experience in deep mining. The Project is planned as a conventional panel caving with the application of hydraulic fracturing to mitigate the seismic hazard during future exploitation. It also considers the construction of the definitive material handling system, consisting of a crushing chamber with a capacity of 60,000 tons per day and a 9 km long tunnel to allocate the conveyor belt. This tunnel is currently under construction and the most complex zones have experienced rockbursts.
This article describes the main elements that integrate the geomechanical risk management and control strategy for the Andes Norte Project, addressing risk concepts and strategies, mine design layouts, rock support design and hydraulic fracturing considerations, in conjunction to experience gained during its construction and also with El Teniente mine experience applied to this future exploitation sector.