Abstract
This paper examines the economic efficiency of Blast Movement Monitors (BMMs) in a grade control environment within open-pit mining operations. Blast-induced displacement of ore-waste contacts remain a major constraint on effective grade control in open-pit mining. Unaccounted movement during blasting frequently leads to ore dilution, loss of valuable material, and misclassification, ultimately reducing processing efficiency and economic returns. The study is based on the premise that blast-induced rock mass movement is inherently stochastic and cannot be reliably reproduced using deterministic modelling alone; therefore, high-precision grade control requires direct in-situ measurement. By capturing three-dimensional displacement vectors from multiple monitoring points within a blast block, BMM enables more accurate reconstruction of post-blast ore boundaries. This multi-point approach accounts for spatial variability and provides a robust basis for updating polygons prior to excavation. In 2024, the pilot implementation of the BMM system was started at the Zhairem Mining and Concentrating Complex (MCC), and the system is being implemented at several Kazakhstan mining companies. Using field data from the Zhairem site, the study quantifies the operational consequences of uncontrolled blast movement, including ore loss, dilution, and misclassification. The results indicate that improved boundary delineation enhances resource utilisation and contributes directly to increased profitability. Based on these findings, the paper proposes a financial value assessment tool designed to support investment decisions related to blast movement monitoring systems, enabling operations to systematically evaluate the cost–benefit ratio of BMM implementation and optimise grade control strategies within a broader economic framework.