With the advent and wide spread use of computers a number of algorithms have been developed to determine the optimum ultimate pit limits in open pit mining. The main objective of these algorithms is to find groups of blocks that should be removed to yield the maximum overall mining profit under specified economic conditions and technological constraints. The most common methods are: Lerchs and ...

We consider the problem of optimal investment and operational planning for development of gas fields under uncertainty in gas reserves. Assuming uncertainties in the size and initial deliverabilities of the gas fields, the problem has been formulated as a multistage stochastic program by Goel and Grossmann (2004b). In this paper, we present a set of theoretical properties satisfied by any feasi...

The Sungun copper deposit is located in about 40km north west of Ahar city in the east Azarbaigan province of Iran. The total geological ore deposit is estimated to be 740 million tons. In this study using all information from exploration and geotechnical studies of the area, final pit limits of Sungun copper deposit is designed by the 2-D Lerchs & Grossmann Algorithm. By this method, from 740 ...

We present an algorithm for solving the minimum-cut problem on closure graphs without maintaining flow values. The algorithm is based on an optimization algorithm for the open-pit mining problem that was presented in 1964 (and published in 1965) by Lerchs and Grossmann. The Lerchs–Grossmann algorithm (LG algorithm) solves the maximum closure which is equivalent to the minimum-cut problem. Yet, ...

This paper presents an Equality Relaxation variant to the Outer-Approximation algorithm for solving mixed-integer nonlinear programming (MINLP) problems that arise in structural optimization of process flowsheets. The proposed algorithm has the important capability of being able to explicitly handle nonlinear equations within MINLP formulations that have linear integer variables and linear/nonl...