Current and Future Stope Design Methods for Underground Mining

Good mine planning is vitally important to mine design, and while mine design can proceed without it, mine planning adds most of the value.

Image Credit: Arfani Mujib/Shutterstock.com

Good planning leads to economical and practical site extraction. Although it is a misunderstood and diminishing practice, it is essential for a viable mining operation. This article will examine the importance of stope design in mine planning and explore current and future methods of stope design for underground mining.

Key Aspects of Stope Design

Before drilling and extraction continues and time and money are invested, key aspects of stope design must be properly considered by planning and production engineers. This is vital for good mine design.

Engineers need to consider stope geometry, including working dimensions and wall angle, and ask questions such as whether the stope can be easily backfilled or bogged down, and whether physical constraints and Production drilling parameters allow drilling to begin.

Key aspects that govern optimal extraction should also be considered. These include the effectiveness of the engorgement using manual or remote techniques, the location of the climb and the stope, the void ratio, the extraction sequence and the sequence of blasting. Drilling and blasting parameters, stope optimization including stope section evaluation, practical stope design, low grade zone and cut-off grade are part of good stope design .

Equipment capabilities and operator expertise should be considered when designing the stope, along with financial factors such as capture costs. Engineers designing the site must also communicate effectively with geologists, and it is important that geotechnical conditions are fully investigated, analyzed and planned during the design process.

Rushing the planning process can lead to critical failures in underground mining, so it is crucial that engineers design things like stopes well and consider several aspects before operations begin. This will significantly improve worker safety and the economic viability of underground mining operations.

Importance of stoping-based methods in underground mining

Felling involves the use of artificial pillars or supports in mining operations, as opposed to unsupported methods.

Stoping has advantages for the mining industry by limiting the impact on the surface, which increases the sustainability of mines. Stoping-based methods cause very little subsidence and contribute to public perception of the mining industry. These methods are cost effective and have already become a common feature of underground mines.

However, there are risks associated with increasingly complex rock geometry as mining operations mine deeper and deeper deposits, creating potentially hazardous conditions for mine workers and equipment. For this reason, it is important to consider each parameter when planning the mine.

Software-Based Optimization Strategies

Open pit optimization has been available since the 1980s. Today, mining engineers use increasingly sophisticated software for design and planning.

Computer modeling gives engineers greater flexibility to optimize site design and selection. Improving underground mining operations is a complex procedure due to the variety of deposits, rock morphologies, mining methods and mine access methods.

Several researchers have developed solutions for individual tasks in mine design and planning processes, as well as for automating manual stope design. Opportunities for developing an integrated methodology and research package have existed for decades, with recent research making a significant contribution to this field.

Several software packages have been developed over the past decades, including multiple tools developed as part of the AMIRA research project. AMIRA’s goal is to create a commercially supported product that can be widely used in the mining industry.

The P1037/P1043 projects have developed optimization engines for each stage of planning and the strategy optimization tool chain. Optimization engines cover building site shapes and layout, development design, access, building site, value hill analysis, computer execution controllers and automated scenario generation, as well as optimization of the shutdown, development and access sequence for the complete life cycle of the mine. A key feature of the project is a search UI that can be replaced with a commercial UI.

Study current developments and identify future opportunities

As the world enters the 4and industrial revolution, the mining industry is benefiting from advanced mathematical modeling, improved software capabilities, improved connectivity, big data paradigms, and vastly improved connectivity.

Using new technologies, stope design is crucial for optimal mine planning and ensuring the sustainability of the industry. Recent developments have focused on site optimization algorithms.

To study the current development and future prospects for stope design, a team writes in Energies conducted a survey of engineers and mining professionals in the industry.

Out of 500 targeted industry professionals, 36 satisfactory results from 20 countries were received by the authors. In the survey, no dominance of a single site design method was found, and even though numerical models have started to replace empirical methods, empirical methods and personal expertise are still widely used by engineers and professionals in the mining industry.

In total, 87% of respondents indicated that they are ready to change site design practices. The most important suggestions for improvement to stope design in the survey include:

  • Collect more geotechnical data
  • Software development
  • Integration into overall mine planning
  • Automating
  • Speed
  • Backfill predictability

Additionally, 45% of respondents have utilized rock mass and ore categorization investigations to improve stope design.

The study has identified that an iterative approach for stope design during multiple phases of mining operations has not been properly established and utilized. However, 69% of all responses have reported changes to the mining method and indicate that the industry is ready to implement new, more efficient stope design methods.

The authors behind the study conclude that if new stope design methods are to be properly implemented and the benefits demonstrated, case studies should play a central role.

References and Further Reading

Janiszewski, M, Pontow, S & Rinne, M (2022) Industry Survey on the Current State of Stope Design Methods in the Underground Mining Sector Energies 15(1) 240 [online] mdpi.com. Available at: https://www.mdpi.com/1996-1073/15/1/240

AMPS (2021) The Importance of Stope Planning Prior to Borehole Design AMPS [online] advancedminingproduction.com. Available at: https://www.advancedminingproduction.com/2021/the-importance-stope-planning-prior-drill-design/

Alford, C & Hall, M (2014) Strategy optimization for underground mines alfordmingsystems.com [online] Available at: https://alfordminingsystems.com/wp-content/uploads/2014/12/Strategy_optimisation_for_underground_mines.pdf

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Abdul J. Gaspar