Abstract This article deals with a study performed at the Experimental Mine of the Research Center of Responsible Mining of the University of São Paulo, to examine the correlations between geological environment, blasting parameters and energy consumption in the primary crushing phase. The research is designed to appreciate the relationships between the energy provided for size reduction and the resistances to size reduction. For this purpose, Key Performance Indicators (KPIs) are used to describe the possible improvements on the energy consumption due to crushing. Four blast tests were performed: for each blast, KPIs were recorded regarding the blast design, the particle size distribution, the real power energy consumption at the primary crushing unit and its rate of utilization. The results show that energy consumption at the primary crusher is a sum of two components: energy directly involved in crushing the rock, and additional energy used for winning the inertial resistances of the moving parts of the crusher. We show how explosive energy and delay times influence the production of coarse fragments that jam the crusher, therefore influencing machinery stops and inertia loads related to putting the jaws back into movement.

Abstract The use of dynamic simulation is technically advantageous for the project as shown by various authors. However, is it economically advantageous in the early stages of the project (FEL1 and FEL2)? The methodology to economically evaluate the use of dynamic simulation considers the time and development cost compared with the time and cost spent to change the project in the next phase, considering changes that could be avoided with the use of dynamic simulation. Five process plant projects were evaluated, each one with an estimated CAPEX of US$ 300 million. The saved average is US$ 44,200.00 and US$ 182,400.00 for FEL 1 and FEL 2 respectively. The percentage cost savings for FEL2 (2.0%) and FEL3 (3.1%) are significant. The estimated delay avoided for FEL2 (3 weeks) and FEL3 (8 weeks) is directly related to the implementation delay, whose cost is expressively greater than the savings shown. The study concludes that the use of dynamic simulation is economically advantageous for the project.

Abstract This article aims to evaluate the use of a truck factor for off-highway trucks in open pit mine operations, thus reducing error on material movement and mine production data entry. This method is current for a copper mine located in South East Pará, Brazil. With a dispatch system, the truck factor is calculated using three data inputs called measured t, dump t and excavator load time. This dispatch system, designed to upload real time data from each truck, acquires measured load information by a truck weightometer and provides the basis for long-term, medium-term and mainly short-term planning. Due to the significant impacts toward mine planning, through data error, a payload truck factor system provides data assurances in place of potential failure of onboard weighing. However, when using a system that is reliant on actual data, caution must be applied when replacing information with assumed fixed figures, thus forming the discussion on which this article attempts to review by providing overview on both the positive and negative impacts of implementing a truck factor system to an open pit mining using a dispatch system.

Abstract This paper presents the results of the application of geophysical surveys to update the morphological model of a limestone and gneiss deposit of a mining company near the city of Taubaté, Brazil. The research began with a test to verify the accuracy of the geophysical survey method and it was conducted in the same area as a previous drilling campaign with the aim of confirming the possibility of using Vertical Electrical Sounding (VES) and induced polarization (IP) methods, in order to obtain the required information for the deposit morphological modeling. As a result, the application of geophysical methods in the study area reduced up to 75% the data collection time and presented similar accuracy levels as conventional exploration methods used for the same research objectives.

Resumen Este artículo presenta los resultados de la aplicación de estudios geofísicos usados para la actualización del modelo morfológico de un depósito de caliza y gneis perteneciente a una compañía minera cerca de la ciudad de Taubaté, estado de Sao Paulo, Brasil. La investigación comenzó con un test de verificación de exactitud del método geofísico de estudio, el cual fue realizado con una campaña de perforación realizada previamente en la misma área de estudio, con el objetivo de confirmar la posibilidad de utilizar los métodos de Sondeo Eléctrico Vertical (SEV) y de Polarización Inducida (IP) para obtener la información requerida para el modelado del depósito morfológico. Como resultado, la aplicación de los métodos geofísicos en el área de estudio redujo el tiempo de recolección hasta un 75% y presentaron un nivel de precisión similar al de los métodos de exploración convencionales utilizados para los mismos objetivos del estudio.

A simulação de lavra depende da utilização de dados coerentes e representativos da operação da mina. Esse trabalho propõe uma metodologia de modelagem de dados especificamente desenvolvida para simulação de lavra. A metodologia proposta foi aplicada a um estudo de caso de mina a céu aberto, onde dados do tempo de ciclo dos caminhões foram modelados para utilização em simulação de lavra. Os resultados da aplicação da metodologia indicaram que todas as variáveis modeladas aderiram a distribuições teóricas após o tratamento de dados, incluindo a remoção de outliers. O estudo identificou a necessidade do rastreamento das causas de inconsistências de dados, para o desenvolvimento de um processo de gestão de dados incorretos da operação de lavra.

Mine simulation depends on data that is both coherent and representative of the mining operation. This paper describes a methodology for modeling operational data which has been developed for mine simulation. The methodology has been applied to a case study of an open-pit mine, where the cycle times of the truck fl eet have been modeled for mine simulation purposes. The results obtained have shown that once the operational data has been treated using the proposed methodology, the system variables have proven to be adherent to theoretical distributions. The research indicated the need for tracking the origin of data inconsistencies through the development of a process to manage inconsistent data from the mining operation.