Spatial entropy for quantifying ore loss and dilution in openpit mines

Effective management of ore loss and dilution is essential for successful grade control and short-term mine planning due to their significant impact on the economic, environmental and technical aspects of openpit mining operations. Factors influencing ore loss and dilution fall into two categories: (1) controllable factors, like mine equipment selectivity and blast design, and (2) uncontrollable factors, such as spatial heterogeneity of ore and waste blocks on a bench. This paper focuses on the second category by applying spatial entropy concept to capture heterogeneity at the scale of selective mining units. In this paper, global spatial entropy is used to assess the impact of spatial heterogeneity between ore and waste blocks on the magnitude of ore loss and dilution, while the local spatial entropy can guide the allocation of blast movement monitoring balls preblast. High values of the global spatial entropy indicate increasing potential of ore loss and dilution, which reduce profit. Furthermore, through a number of case studies, the study investigates the relationship between spatial entropy, cutoff grades, blast movement, dig-limits optimization model running time, and profit. The results show that changes in cutoff grade and blast movement can significantly affect spatial entropy post-blasting and increase ore loss, dilution and profit reduction, revealing the need for controlled blasting at specific bench sections. Additionally, the results demonstrate an exponential increase in profit reduction due to ore loss and dilution with a rising global spatial entropy