International Journal of Mining and Mineral Engineering (8 papers in press)
Implementation of Industry 4.0 technologies in the mining industry a case study
by Arnesh Telukdarie
Abstract: In modern mining, it is imperative to have a real-time flow of information between enterprise level and shop floor systems. The gaps that exist between these spheres make it difficult for managers to have timely information for optimum decision making. A mining company needs instantaneous visibility on production, quality, cycle times, machine status, and other important operational variables to achieve optimum and effective operations. With the implementation of Industry 4.0 technologies at a Mine, the integration of fragmented shop floor and the enterprise level systems enables seamless communication in delivering optimum operations. This research demonstrates Industry 4.0 technologies as the mechanisms for integrating business systems, manufacturing systems and processes. The Industry 4.0 methods researched are deployed using Software Development Lifecycle (SDLC) process at a mining company to integrate systems such as manufacturing, plant, business partners, and SAP ERP. The results introduce a semi-smart Mine with real-time visibility of the overall mining status.
Keywords: Industry 4.0; Internet of Things; Industrial Internet of Things; Cyber Physical Systems; Big Data; ERP.
Effect of aggloflotation of coal slimes by use Flomin C9606 as a collector
by Richard Kasomo, Sammy Ombiro
Abstract: In many coal preparation plants and concentrators, coal slime (ultra-fine coal) form the major challenge due to difficulties in processing and upgrading. Several techniques are currently being devised in coal and mineral industries to aid in beneficiation of the coals in their finer sizes. Most of the ultra-fine coal particles are processed by oil agglomeration, selective flocculation or hydrophobic flocculation flotation techniques. In this research the main focus was hydrophobic flocculation flotation to utilize the ultrafine coal particles. In the study, the conventional flotation batch tests were conducted to determine the best collector and the best dispersant for this coal, then Flocculation experiments were carried out followed by the flotation. The effects of fundamentals parameters such as the type and dosages of flocculating reagents, the impeller stirring speed and the grinding fineness were also investigated. The optimum conditions for research were as follows: Flomin C9606 was determined to be the best collector, sodium Hexametaphosphate as the best dispersing agent, the impeller speed was determined to 1500rpm, and the best grinding fineness was achieved at 30 minutes. When the sample was processed by the flow sheet consisting of one stage rougher and one stage cleaner, the ash content of the raw coal was reduced from 22.73%, (raw coal) to 6.39%. This was achieved by four stage flotation cleaning with the solid combustible matter recovery of 86.28%. The overall ash reduction was 73.57% which met the minimum requirement to be used as a clean coal product in industries. It was therefore concluded that hydrophobic flocculation flotation using Flomin C9606 was capable of cleaning ultra-fine coal to obtain the clean coal product.
Keywords: Coal slimes; hydrophobic flocculation flotation; Flomin C9606; Froth flotation.
Impact of hydraulic fracturing and borehole spacing on gas drainage along coal seam
by Huayong Lv
Abstract: Hydraulic fracturing is a technology employed to improve coal seam permeability and gas drainage. This study uses theoretical analysis and field testing to examine the mechanisms of hydraulic fracturing of a coal seam, including the initiation conditions of boreholes and cracks, main crack forms, and expansion and extension processes. RFPA2D-flow software was used to develop a numerical simulation of double-hole hydraulic fracturing, from crack initiation to expansion and extension in the coal body. The numerical simulation revealed characteristics and evolution of the stresses, water pressure and acoustic emission around the boreholes and estimated the permeability improvement range of fracturing holes under conditions of different hole spacing. Results of a field industrial test showed that the daily gas drainage pure flows increased by 5.817.6 times, the average gas drainage velocity reached 3.76 m3/min (maximum 10 m3/min), the gas drainage rate of the working face reached 57.32%, and the influence radius of single-hole hydraulic fracturing is approximately 5 m. This study demonstrates that hydraulic fracturing and permeability improvement technology can greatly improve the gas drainage rate of boreholes in a coal seam.
Keywords: Hydraulic fracturing; Crack expansion and extension; Pressure relief and permeability improvement; Gas drainage.
Special Issue on: ISCSM 2018 Advances in Continuous Surface Mining
Ultimate pit limit determination for fully mobile in-pit crushing and conveying systems
by Edward Hay, Micah Nehring, Peter Knights, Mehmet Kizil
Abstract: Fully-mobile in-pit crushing and conveying systems have different pit shape requirements to traditional truck haulage systems due to linear bench and flat floor constraints imposed by conveyor systems. As the shape of a pit is largely based on the ultimate pit limit, it is desirable to have the additional shape requirements of fully mobile in-pit crushing and conveying systems included in the ultimate pit limit determination process. This paper discusses and highlights why there are different requirements for these systems, and what they are. A method of including these extra requirements during ultimate pit limit determination is presented. A case study has been included that shows the method working successfully, with scheduling of the pits to further highlight fully mobile in-pit crushing and conveying viability. This case study shows that through the reduced mining costs, a fully mobile in-pit crushing and conveying pit can return a higher Net Present Value than the traditional truck and shovel pit for the same deposit. The development of this method provides the opportunity for the metalliferous industry to accurately determine ultimate pit limits for mines considering the use of fully mobile in-pit crushing and conveying systems.
Keywords: in-pit crushing and conveying; IPCC; mine planning; ultimate pit limit; UPL; FMIPCC; pit optimisation.
Lignite Mine Monitoring and Mapping Using Freely-Available Radar and Optical Satellite Imagery
by Marianthi Stefouli, Antigoni Panagiotopoulou, Eleni Charou, Yiota Spastra, Emmanuel Bratsolis, Nicholas Madamopoulos, Stavros Perantonis
Abstract: A methodology for monitoring and mapping Lignite Mining areas using Sentinel-1 and Sentinel-2 ESA Copernicus satellite systems is presented. A Stochastic Regularized Super-Resolution Reconstruction (SRSR) for the enhancement of the Sentinel-2 optical data is developed and a Land Monitoring/Change Analysis based on the enhanced Sentinel-2 images is performed. Additionally, the ground motion is monitored using the Sentinel-1 radar data via the Rheticus Service. The proposed methodology is tested on the Amyntaio lignite mine in Ptolemais basin, Greece, for Sentinel images obtained from 2014 to 2018. The Amyntaio area has been of particular interest, as a landslide event occurred on June 10th, 2017, causing major operational disruption and a severe economic loss to the Public Power Plant Cooperation of Greece SA. The methodology proves to be useful for facilitating mapping and monitoring mining and post-mining areas facing similar problems with the Amyntaio lignite site.rn
Keywords: Keywords: Lignite; Surface Mining; Landslides; Radar; Sentinel-1; Ground Motion; Rheticus service; Multispectral; Sentinel-2; Super-Resolution Reconstruction; Lorentzian Estimator; BTV Regularization; Self Organizing Maps; Land Cover Change Analysis.rn.
A Real-Time Event-Driven Database Productivity and Maintenance Planning tool for Continuous Surface Mining Operations
by Zach Agioutantis, Stamatini Delmadorou, Nikos Steiakakis, Chrysanthos Steiakakis, Stergios Papaterpos
Abstract: This paper presents a data management application driven by real time events, which has been developed as a Productivity and Maintenance Planning software application to be used in the surface lignite mines in northern Greece. The mines operate using a continuous mining system comprised of multiple bucket wheel excavators, belt conveyors, spreaders and stackers. There is a control center for each mine, comprising of Aspect Servers, OPC servers and a SCADA system which interfaces with PLCs at each equipment unit in the field. The overall data management infrastructure is installed on the main network system and draws data from the OPC servers at each mine. In order to collect the data, the application is developed using event driven functionality as well as data polls. Data can then be modified by the control tower personnel. The application generates reports on a daily basis for production monitoring, productivity, equipment performance and utilization as well as various maintenance tasks. The system has been in operation at the surface lignite mines in northern Greece since 2011 and has been embraced by mine personnel for decision making and planning.
Keywords: SCADA; OPC; PLC; database; continuous mining system; productivity; maintenance; belt conveyors.
Exploring the effect of physical, human and technical factors on Bucket Wheel Excavators Efficiency: A Fuzzy Cognitive Map Approach
by Maria Menegaki, Theodoros Michalakopoulos Michalakopoulos, Christos Roumpos
Abstract: Several parameters, e.g. characteristics of the excavated material, number and thickness of lignite layers, bucket wheel capacity, experience of personnel, etc., affect the efficiency of bucket wheel excavators (BWEs). In this paper, the FCM (Fuzzy Cognitive Map) approach is used to explore the factors affecting the efficiency of BWEs as well as their interlinkages and interdependencies, based on an extensive review of scientific literature and expert intervention. The main goal is to provide a transparent and flexible model and propose a different simulation approach for complex mining systems that can interconnect the factors influencing systems behaviour. The implementation of the proposed model revealed significant differences in BWEs efficiency under favourable and hostile conditions. This is a first step towards simulations intended to help mining practitioners, bridging the gap between pure qualitative and quantitative approaches.
Keywords: bucket wheel excavators; efficiency of BWEs; fuzzy cognitive mapping; soft modelling; learning algorithms.
Surface Mining in Western Macedonia, Greece: Fugitive Dust (PM10) Emissions and Dispersion
by Athanasios Triantafyllou, Symela Andreadou, Nikolaos Moussiopoulos, Stylianos Garas, Ioannis Kapageridis, Georgios Tsegas, Christos Diamantopoulos, Christos Sachanidis, Ioannis Skordas
Abstract: In the operation of large open-pit lignite mines (extracting and handling excavation materials) a series of significant fugitive dust emission sources are recorded. The quantification of the emissions of each source and the investigation of atmospheric dispersion are subjects of great interest for the development and implementation of air quality management systems in the neighbouring residential areas. The study aims to investigate and locate the fugitive dust sources in the surface mines operated in Western Macedonia in NW Greece, and quantify their contribution to the total fugitive dust (PM10) emissions produced by the mines activities. The contribution of each emission source recorded was quantified. An effort was also made to investigate the dispersion of fugitive dust emitted from each individual mine and source activity and assess the contribution of the mining activities to the air quality of the surrounding areas, by using a three-dimensional, nestable, prognostic meteorological, and air pollution model. The results can contribute to the implementation of measures and scenarios for the air quality management in the area.
Keywords: Fugitive dust; PM10 emissions; dust dispersion; surface mining; lignite; continuous mining.