Integrated Optimization of Drill & Blast, and Comminution Processes at Lundin Mining -Chapada

Evangelista, Moreira, Moura, Souza, Resende, Lisboa, Corsini, Ribeiro, Valery, Valle, Hayashida, Plasencia

Presented at Procemin-GEOMET 2021

ABSTRACT

Hatch and Enaex conducted a joint Mine-to-Mill optimization project at Lundin Mining’s Chapada operation in Brazil. The main objective was to maximize plant throughput with existing equipment while maintaining the product size of the comminution circuit. The project included a review of the available ore characterization data, ore domain definition, drill and blast operating practices, mining and processing operations, in-depth data analysis of historical process variables, planning and supervision of a full Mine-to-Mill survey, rock characterization for the surveyed ore, and the development of mathematical models for blasting and comminution, or updates to existing models where available.

The calibrated, site-specific models were used in conjunction with comprehensive data analysis and ore domain definition to conduct simulations and integrated optimization of the 2 drill and blast and comminution processes. A set of blasting guidelines were proposed, which consisted of optimized drill and blast designs for each ore domain, as defined by a combination of site lithology classifications, rock strength, and rock structure. These blast guidelines were tailored to each domain to provide an optimized and consistent Run-of-Mine (ROM) fragmentation for downstream processes. The comminution circuit would receive finer feed with the optimized blasting, with further opportunities for improvement identified in the comminution circuits themselves. These opportunities included changes to the operating conditions of the primary and pebble crushers, as well changes to the Semi-Autogenous Grinding (SAG) and ball mills – including optimising the design of the shell lifters/liners, SAG grates and pulp lifters, ball charge level and media size – and cyclones.

Taken together, these improvements ensure that the benefits of the improved ROM PSD are fully realised, and throughput maximised. The predicted benefit from the full implementation of the
recommendations was an increase in plant throughput of 13 – 22 % (for the Soft-Fine to Hard-Coarse domains, respectively) while maintaining the final grinding product size below the target. The recommendations are currently being implemented, with throughputs of between 3,300 – 3,500 tph achieved to date. This is consistent with the predictions of the study for the current extent of implementation. If the recommendations are implemented in full, sustained throughput rates above 3,500 tph are expected to be achieved, all while maintaining the product size.
The recommendations provided were practical to implement for both the mining and processing groups at Chapada, with no significant capital investment involved in the project.

AUTHORS

Glauber Evangelista1, Alderney Moreira2, Flavio Moura3, Igor Souza4, Fabio Resende5,
Paulo Henrique6, José Corsini7, Augusto Ribeiro8, Walter Valery9, Roberto Valle10,
Rodrigo Hayashida11 and Claudia Plasencia12
1. Process and Development Coordination/ Beneficiation Management/ Chapada Mine, Lundin
Mining, Brazil, Process Specialist, This email address is being protected from spambots. You need JavaScript enabled to view it.
2. Process and Development Coordination/ Beneficiation Management/ Chapada Mine, Lundin
Mining, Brazil, Process Coordinator, This email address is being protected from spambots. You need JavaScript enabled to view it.
3. Process and Development Coordination/ Beneficiation Management/ Chapada Mine, Lundin
Mining, Brazil, Beneficiation Manager, This email address is being protected from spambots. You need JavaScript enabled to view it.
4. Mine Engineering Coordination/ Mine Operation Management and Short-Term Planning/
Chapada Mine, Lundin Mining, Brazil, Mine Engineer Coordinator,
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5. Mine Engineering Coordination/ Mine Operation Management and Short-Term Planning/
Chapada Mine, Lundin Mining, Brazil, Mine Operations and Short-Term Planning Manager,
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6. Mine Engineering Coordination/ Mine Operation Management and Short-Term Planning/
Chapada Mine, Lundin Mining, Brazil, Drill and Blast Supervisor,
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7. EMTS, Enaex, Brasil, Technical Assistance Manager, This email address is being protected from spambots. You need JavaScript enabled to view it.
8. EMTS, Enaex, Brasil, Technical Assistance Coordinator, This email address is being protected from spambots. You need JavaScript enabled to view it.
9. Mining and Minerals Processing, Hatch, Australia, Global Director - Consulting and
Technology, This email address is being protected from spambots. You need JavaScript enabled to view it.
10. Mining and Minerals Processing, Hatch, Peru, Director Process Improvement,
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11. Mining and Minerals Processing, Hatch, Brazil, Principal Drill and Blast Consultant,
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12. Mining and Minerals Processing, Hatch, Peru, Process Engineer, This email address is being protected from spambots. You need JavaScript enabled to view it.