Technical-economic evaluation of low-grade resources and its application for gold mines

A technical and economic evaluation model for low-grade resources in Jiaojia Gold Mine was built up based on the breakeven theory. In different production stages, the corresponding follow-up cost was calculated, based on which the low grade resources were evaluated and classified. Differential grades were calculated to determine whether it is worthy to recovery them. The threedimensional deposit model in combination with Supac software was adopted to estimate and evaluate low-grade mineralized deposits in Jiaojia Gold Mine. Given the gold price of RMB ￥ 180 g^-1, the application of differential grade can bring the mine additional 2.73 t gold metals, as well as RMB ￥ 7 500 million profits.