Selection and assessment of mining equipment used in open pit rock mines relies chiefly on estimates of overall exploitation cost. The rational arrangement of mining equipment and systems comprising loading machines, haul trucks and crushing plants should be preceded by a thorough analysis of technical and economic aspects, such as investment outlays and the costs of further exploitation, which largely determine the costs of mining operations and the deposit value. Additionally, the operational parameters of the mining equipment ought to be considered. In this study, a universal set of evaluation criteria has been developed, and an evaluation method has been applied for the selection of surface mining equipment and the processing system to be operated in specific mining conditions, defined by the user. The objective of this study is to develop and apply the new methodology of multi-criteria selection of open pit rock mining equipment based on multiple criteria decision-making (MCDM) procedures, to enable the optimization of loading, handling and crushing processes. The methodology, underpinned by the principles of MCDM, provides the dedicated ranking procedures, including the ELECTRE III. The applied methodology allows the alternative options (variants) to be ranked accordingly. Ultimately, a more universal methodology is developed, applicable in other surface mines where geological and mining conditions are similar. It may prove particularly useful in selection and performance assessment of mining equipment and process line configurations in mining of low-quality rock deposits. Therefore, we undertook to develop universal criteria and applications for the selection and performance assessment of process machines for surface mines, taking into account environmental aspects as well as deposit quality.
The article presents an analysis of the influence of selected operating environment parameters on the operation of a technological system in a mine and examines the profitability of exploiting a deposit of low quality. A model based on a cyclical transportation system in a surface limestone mine, developed in the Haulsim software, served to evaluate—from an economic perspective—several material transportation scenarios depending on the quality of the deposit. A discrete simulation of machine operation allowed a detailed analysis of the technological, operating and economic parameters for selected solutions. The results may be the basis for a decision to begin or to resign from mineral extraction. The simulation results demonstrate that maintaining the operating environment in good technical condition positively influences machine operating cycle times, the required total time of the transportation task and the operating costs. The analysis was performed for the production period of one full year, allowing for the effective work and technological downtimes. This approach allowed the usefulness of the model to be demonstrated in evaluating not only the effectiveness of individual technological procedures but also its economic aspect, related to a decision on the exploitation of “difficult” deposits.
In mining projects and production operations, energy carrier costs (fuel, electricity) constitute the primary component of variable costs. This study outlines a methodology for projecting operating costs in a surface mine or quarry in order to find the optimal configuration of mining equipment to extract low-grade secondary deposits, taking into account volatile energy prices. For illustration, the operating costs of five variants of mining equipment deployed to mine low-grade products were analysed, with the price of energy and fuels being the key cost component and the main risk factor. There were differences between the initial investment outlays and operating costs involved in all analysed variants, whilst the starting point for estimating the technical and economic parameters involved in the respective solutions was the predefined configuration of the mining equipment. Further, the decision to commence or discontinue mining operations could be supported by the simulation procedure based on the economic model. The results provided valuable insights into the cost-effectiveness of low-grade deposit extraction scenarios, depending on the projected unit costs of fuels and energy.
This study investigates the factors influencing the energy consumption and reliability of haul trucks in open-pit mines and quarries, where fuel costs and the environmental impact are significant. Traditional analysis of haulage systems often overlooks crucial aspects such as energy efficiency in the specific mining environment and the effect of road configurations on truck performance. As sustainability becomes increasingly important, reducing fuel consumption not only reduces costs but also reduces greenhouse gas emissions. A key focus of the study is the link between haul truck reliability and overall efficiency. Frequent breakdowns increase maintenance costs, lead to unplanned downtime, and increase fuel consumption, all of which have an impact on the environment. Reliable transport systems, on the other hand, improve efficiency, reduce costs, and support sustainability goals. The authors analyze the energy consumption of trucks in relation to vehicle performance parameters and transport route characteristics. Discrete modeling of the transport system showed the impact of the operating environment on the variability of energy consumption and vehicle reliability. The study highlights the importance of understanding specific energy consumption in order to optimize the choice of transport system, as transport costs are a major cost of resource extraction. By analyzing the effect of road quality on vehicle performance, the authors suggest that improvements to the road surface can more easily improve vehicle reliability and energy intensity than changes to other road design elements. The study presents a quantitative analysis of the impact of haul road conditions on the operational efficiency of haul trucks in mining environments. Through discrete simulation models, two scenarios were analyzed. Total operational time decreased by 11.2% when road quality improved, demonstrating the critical role of surface maintenance. Additionally, breakdown times were reduced by 44%, maintenance by 15%, and empty travel by 9% in the optimized scenario. These findings underscore the necessity of maintaining optimal road conditions to prevent substantial efficiency losses and increased maintenance costs.
The main objective of this study was to develop a comprehensive testing method for powered roof supports operating under real mining conditions and to establish guidelines for a monitoring system designed to record their geometric and operational parameters. The proposed methodology included analyses of load-bearing capacity limits, laboratory model tests, bench tests, and in situ investigations under actual working conditions. Based on these studies, a detailed testing procedure was developed, defining the sequence of experimental stages, the selection and calibration of sensors, their installation and servicing methods, as well as the integration of measuring equipment with the support structure. The key results demonstrate that the proposed method allows for reliable acquisition and interpretation of data concerning the operational behavior of powered roof supports. The findings enabled the identification of critical geometric and operational parameters influencing the stability, durability, and efficiency of the support system. The developed monitoring procedure, supported by both laboratory and field tests, provides a consistent and replicable framework for assessing the performance of roof supports in real-time mining operations. The conclusions confirm that the presented approach represents an innovative and systematic method for evaluating and monitoring powered roof supports under real conditions. The main contribution of this work lies in the formulation of universal guidelines for the design and implementation of monitoring systems, significantly improving the safety, reliability, and efficiency of mining processes.
1 November 2019 in IOP Conference Series: Earth and Environmental Science
The growing importance of the cost of electricity in coal mining, changes in the value chain in recent years and new commodity exchanges cause that mine operators independently or vertically integrated with power plants have possibility to buy and sell coal and electricity and create a specific spread. The study of risk based on the concept of a new indicator: an intrinsic spread. The intrinsic spread is calculated as a difference between the income from the sale of coal and the cost of purchasing the energy required for the coal production. This indicator shows a market risk in the coal mine in a better way, because except for income it includes a part of the cost of exploitation which can be hedged in the exchange market. Spread calculations were made on historical data and simulation modelling. Based on time series of coal and energy prices for various contracts and spot prices obtained from the EEX the impact of the type of contracts on the volatility of the intrinsic spread in subsequent periods measured by the standard deviation of returns has been analysed. It was found that hedge using futures helps to reduce the risk in the mine. Modelling of coal prices and electricity was carried out by conventional financial market econometric models. The best-fitting econometric models are multivariate models and models based on the copulas. The simulation results show that the use of futures contracts contributes little to reducing the intrinsic spread volatility. An econometric model with the technical and economic parameters of the mine typical for hard coal mine has been built. Changes in fixed and variable costs have been simulated based on triangular distributions. Parameters for simulation were estimated based on the economic data from the mines. Additionally, coal and energy prices were dependent on the market volatility. Based on the economic model and Monte Carlo simulation it has been found that the proposed method may be helpful in reducing the coal mine market risk.