Non-Gaussian Copula Simulation for Estimation of Recoverable Reserve in an Indian Copper Deposit

Abstract

The present study developed a geostatistical simulation technique based on non-Gaussian copula for recoverable reserve estimation considering support effect of a well-known open-pit mine of a copper deposit in India. The focus was to examine the efficacy of copula-based simulation model in recoverable reserve estimation. It was assessed by comparing three selectivity curves like grade–ore tonnage, grade–metal tonnage and ore–metal tonnage of reserve constructed using the copula-based simulation, disjunctive kriging and multi-Gaussian kriging with respect to the production data of blasting. The results informed that the copula-based simulation technique provided better accuracy than the nonlinear geostatistical techniques of disjunctive kriging and multi-Gaussian kriging. The root mean square error and standard error analysis indicated that the copula-based simulation model provided more accurate estimates compared with disjunctive kriging and multi-Gaussian kriging. All the three techniques yielded biased estimates, but the least bias was attributed to the copula-based simulation technique.