Methodology for selection of the variant for opening the deeper parts of the Toranica mine

Opening an underground mine or part of it presents complex and responsible issue, which affects the economy and effectiveness of the mine operation. This paper presents a methodology for selecting the optimal variant for opening, the lead-zinc ore mine Toranica, Macedonia. Six variants of opening and haulage of ore and waste rocks in the deeper parts of the ore deposit have been considered. After the performed analysis, the optimal variant for opening and haulage for the Toranica mine was determined.

DTA/TG analysis of mechanochemicaly activated sodium carbonate

Sodium carbonate is a material that is very good sorbent of carbon dioxide from the atmosphere, and it is a reason of it is increasing importance in environmental protection. In order to improve it is sorption characteristics, activation of Na2CO3 was performed by mechanochemical procedure and monitoring of changes during the relaxation time. This research is based on differential thermal analysis with thermogravimetry, in order to determine the changes that occurred on the activated samples during the relaxation period under controlled conditions. Sodium carbonate was activated for 2 and 7 minutes in a vibro mill, and then the activated samples were deposited in at room temperature and atmosphere of carbon dioxide at a humidity of 95% for 96h.

Application of MCDA in the determination of optimal block size for open-pit modelling and mine planning

The process of creating a geological block model as the basis for a further detailed design and planning of mining operations is a very responsible task. Errors made during this initial process are transferred to all other phases of the mining project. Certainly, one of the most important decisions for the modelling process is the choice of the appropriate size of the blocks that form the model itself. The determination of the optimal block size is not a simple process, because it depends on a large number of affecting factors and criteria. This process can be significantly facilitated by the application of multi-criteria analysis methods, which enable establishment of interdependence between the criteria in order to select the optimal solution. This paper presents the possibilities of applying the Analytical Hierarchical Process (AHP) method for selecting the optimal block size for the needs of the coal deposit modelling process and mine planning, as well as the way in which this method can significantly facilitate problem solving, by looking at it from several aspects. The analysis included six criteria and four potential solutions, and the results themselves indicated the advantages and disadvantages of the applied method.

Primary crusher site selection in open pit mines: Case study in Sungun copper mine

Facility site selection, (such as Primary or in pit Crusher location) is one of the most important steps in mine design process that has a significant impact on economy of the mining operation. This study covers an attempt to find the optimal location for primary crusher in order to support the expansion of Sungun copper mine, which is the second largest open pit mine in Iran. Recent exploration drilling has led to a considerable increase in the ore reserve. Therefore, Sungun started the studies followed with an expansion plan with the goal to increase the capacity from 14 to 28 Mt/Year within the next 8 years. In this paper, 14 effective parameters for finding the best location for a new crusher in five possible options were considered. The options were evaluated based on weighted linear combination method. The results show that the location in South East part of the open pit is the best option for locating of the new crusher. Finally, based on the economic parameters and copper price forecasts, pit optimization and sensitive analysis are applied. Results show that in the worst case, just 0.17 % of ore reserve is affected by the selected area and the minable reserve can cover 78 years of operation.

Suppliers ranking in production systems by Fuzzy TOPSIS method, case study: Underground Coal Mines Resavica-Serbia

Selection and evaluation of suppliers is a complex issue that depends mostly on the quality of the decision-making process. The aim of this paper is to point to the possibility of applying multi-criteria analysis (Fuzzy TOPSIS method) for the selection of suppliers operating in mining systems in the case of the Public Company for Underground Coal Mining Resavica (JPPEU Resavica) -Serbia. Ranking of companies is done based on ten criteria, and it has considered a list of five suppliers (Supplier 1; Supplier 2; Supplier 3; Supplier 4; Supplier 5). The criteria cover the most important aspects of suppliers' selection such as: management and organization, quality, technical ability, production facilities and capacity, financial position, delivery, service, relationship-connectivity, security and environmental protection and price. In doing so, it has used the experts knowledge from JPPEU Resavica to determine the significance and impact of certain criteria to the process of supplier selection and evaluation of suppliers in regard to each criterion. Fuzzy TOPSIS method was used for determining the final ranking of suppliers. The supplier with the top rank was the Supplier 4. The obtained results indicate that the proposed method gives excellent results and can be used for solving various, and the most complex problems that occur in mining systems, as well as in other production systems.

Okinawa Trough geophysical and topographic modeling by GDAL utilities and GRASS GIS

This paper presents using GDAL utilities and GRASS GIS for topographic analysis of the raster grids based on GEBCO DEM as NetCDF file at 15 arc-second intervals. The focus study area encompasses the area around Okinawa Trough, Ryukyu trench-arc system, southern Japan, East China Sea and the Philippine Sea, West Pacific Ocean. Several GDAL utilities were applied for data processing: gdaldem, gdalwarp, gdalinfo, gdal_translate. The data were imported to GRASS GIS via r.in.gdal. Data visualization highlighted high resolution and accuracy of GEBCO grid, enabling topographic modelling at the advanced level. The algorithm of DEM processing, implemented in GDAL utility gdaldem, was used for generating multi-purpose topographic models: aspect, hillshade, roughness and topographic indices, such as Topographic Position Index (TPI), Terrain Ruggedness Index (TRI). Thematic maps (topography, geoid, marine free-air gravity) were visualized using GRASS GIS modules for raster (d.rast, r.colors, r.contour) and vector (d.vect, v.in.region, d.legend) data processing. The results demonstrated smoother bathymetry in the East China Sea and rugged relief in the Philippine Sea which corresponds to their different geological and geophysical settings. The presented methodology of the topographic analysis based on DEM demonstrated technical aspects of GDAL and GRASS as scripting approach of advanced cartography.

X-ray diffraction and SEM analysis of waste sulfur modification for use in concretes

Secondary sulfur obtained as a by-product in the oil refining process is a major problem as an environmental pollutant. One of the possibilities of environmental protection is the use of sulfur obtained in this way as a component of sulfur concrete. Mixing of sulfur with suitable additives can provide longer working lifetime of sulfur concrete, as well as maintenance of the former physical, chemical, and mechanical properties of concrete. Such mixtures are usually called modified sulfur or sulfur cement. Secondary sulfur produced in the oil refining process by the Klaus process (approval of crude oil) cannot be used in this form. In order to be ready for the use of sulfur concrete and asphalt, it is necessary to modify elemental sulfur from cyclic to chain form, obtaining of modified sulfur whose application is as a binding agent in a concrete instead of portland cement is described in this paper. Influence of dicyclopentadien, an organic additive, on sulfur modification has been studied in this research. Microstructure and mineral analysis of modified and unmodified sulfur cement binding are performed using polarized and scanning electron microscopes and X-ray diffraction spectrometer.

Paste backfill materials for underground mining: Some experiences in Serbia: Part II

This review paper presents the backfill method and materials for paste backfill method which are used in the world practice of underground mining. The paper consists of two parts. The first part (Part I) provides a brief literature review concerning the presentation of the backfill method, mostly the paste backfill method, its application, advantages and disadvantages, and materials that can be used to form a paste. The second part (Part II) of the paper presents an overview of possible materials that could be used for the eventual application of this method in Serbia. Flotation tailings from lead-zinc mines and copper mines, fly ash from thermal power plants and metallurgical slag can be potentially used materials for this method. This paper presents the characterization of these materials from some localities in Serbia and results of some investigations in this area.