Panel caving is an underground mining method that relies on continuous rock breakage using gravity. It provides an efficient and controlled method of excavating ore into a catchment, called a drawbell. These drawbells eliminate the need for continuous drill and blast operations in a single panel and allow for loading and hauling of ore. Optimizing the design and technology features ensures productive drawbells throughout the mine and reduces operational and construction costs.

Resolution Copper asked the team to construct a drill and blast drawbell design for a panel caving operation located 5,000 to 7,000 ft underground. The primary objective was to design both a typical drawbell and a drawbell with newer blasting technologies and free face reduction or elimination.

The team prioritized safety while optimizing the number of drillholes, charging cycles, operational efficiency, cost and sustainability to maximize productivity per unit cost. To do this, the team collaborated weekly with the project sponsor and periodically with external resources, used empirical methods for design validation, and synthesized a risk assessment matrix. The team completed a tradeoff analysis and created an iterative and adaptable quality assurance and quality control program. The program contains a list of systematic procedures for meeting and verifying product quality and a corrective decision-making process to identify, fix and prevent errors.

Industry consortium the Next-Generation Design Alliance conducted a prefeasibility study for a copper leach-only operation in central Arizona. These operations rely on detailed plans and carefully designed drainage pads for leaching out copper from the ore to maximize production and minimize waste. Using provided project parameters and block models, the team developed a mine plan and leach pad design that leverages advanced mine planning software for pit optimization. This project challenged team members to use their mineral processing expertise and apply industry-relevant methodologies for optimizing operational efficiency to create the leach pad design.

The team began by evaluating the economics of a leach pad expansion. The design included location selection for the leach pad and collection pond, liner design, and the sequence and stacking for the pad. The team also conducted a stability assessment and incorporated environmental and permitting considerations. In addition, the project includes a process flow sheet, tons, mass balance, time rate and recovery estimates for metal recovery. Finally, the team conducted a trade-off study for trace
mineral recovery including gold, silver and molybdenum.