Monitoramento de overbreak/ underbreak no desenvolvimento da mina subterrânea Ipueira

Abstract

the interior of Bahia. The study was conducted in a technical and systematic manner, aiming to identify the causes and propose actions for its reduction, in order to minimize operating costs and geotechnical risks associated with the advancement of underground galleries. The methodology adopted involved the collection and analysis of operational, topographic, and geological data, in addition to the application of continuous improvement tools, such as the DMAIC method, as well as the reconciliation between projected and executed solids using Vulcan and GEM4D software. Simulations were performed in Paradigm software, based on geomechanical parameters and lithological properties (serpentinites, marbles, and chromitites), in order to evaluate energy distribution and damage to the rock mass. The study also optimized the firing plan and adjusted the drilling grid, including tests with 45 mm bits and the use of low-density emulsions such as Densiex UG. An action plan was implemented covering improvements in drilling, topographic marking, loading, and operational control, in addition to training the teams involved. The RCS (Control Rig System) and benchmarking practices with other companies in the mineral sector were reestablished. As a result of these actions, the average initial overbreak was 41%, and with a reduction target of 34%, a percentage of 27% was achieved after the implementation of the improvements. This reduction provided economic benefits with savings of 552,743 thousand in cleaning and 72,779 thousand in sanitation, in addition to gains in operational safety. Thus, overbreak control depends on the integration of geological and operational factors, with the use of continuous improvement tools and standardization of drilling and blasting parameters being fundamental. The study therefore reinforces the importance of technical monitoring and continuous improvement for operational safety and cost reduction.