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, ...

The determination of the “optimum pit limit” of a mine is considered to be a fundamental problem in mine planning as it provides information which is essential in the evaluation of the economic potential of a mineral deposit, and in the formulation of long-, intermediate-, and short-range mine plans. A number of mathematical techniques have been proposed to solve this problem, some of the more ...

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 ...

represented by a block model that divides the orebody into a three-dimensional array of blocks. Each block consists of a cluster of similar characteristics such as rock type and ore grade, and has attributes such as tonnage of ore contained within the block and an expected economic value (Bley et al., 2010). For each block, the mine production scheduling problem consists of the decisions of (1)...

Existing methods of pushback (phase) design are reviewed in the context of “gap” problems, a term used to describe inconsistent sizes between successive pushbacks. Such gap problems lead to suboptimal open pit mining designs in terms of maximizing net present value. Methods such as the Lerchs– Grossman algorithm, network flow techniques, the fundamental tree algorithm, and Seymour’s parameteriz...

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 ...

O planejamento de mina é desenvolvido considerando variáveis econômicas, teores, litologia, posição espacial. Estas são utilizadas para determinar o limite final cava e sequenciamento das operações. Normalmente amostradas exaustivamente somente as relacionadas ao teor. As demais configuradas com valores médios. técnicas estatística multivariada permitem maior impacto. Utilizando um modelo geoló...

Three-dimensional block models are the most frequently used tool for estimating mineral resources and reserves within a deposit. In open pit mining, basis of mine design long term mining schedule is calculation ultimate limit. The limit with highest profit value. Over years, different algorithms have been developed that enable us to calculate final pit: floating or mobile cone, cone II its corr...

The open-pit mining problem is to determine the contours of a mine, based on economic data and engineering feasibility requirements in order to yield maximumpossible net income. This practical problem needs to be solved for very large data sets. In practice, moreover, it is necessary to test multiple scenarios taking into account a variety of realizations of geological predictions and forecasts...