Abstract:Pit limit design has, up to date, focused mainly on maximization of economic profit alone, with environmental and social issues largely ignored. This paper focuses on incorporating both environmental and social issues in the pit limit design process and provides an approach to pit limit optimization that is in compliance with sustainable development. The case study demonstrates that ecological costs have a substantial down-sizing effect and social benefits have a substantial up-sizing effect on the optimal pit limit. When the ecological costs are factored in, the optimal pit limit is 37.5% smaller than the economically optimal pit limit. However, when the social benefits are factored in, the optimal pit limit is 48.3% larger than the economically optimal one. The overall optimal pit limit, with the economic profit, ecological costs and social benefits simultaneously considered, is a result of balancing conflicting goals of maximizing economic profit, minimizing ecological cost, and maximizing social benefit.

Key words: open pit mine; pit limit; economic profit; ecological cost; social benefit; sustainable development