Scientific Mining Journal

Scientific Mining Journal

Volume 59 - No 3 (September 2020)
INVESTIGATION OF BLAST FRAGMENTATION MODELS IN A SANDSTONE QUARRY
DOI 10.30797/madencilik.792386 Türker Hüdaverdi, Özge Akyıldız
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The existing blast fragmentation models were investigated in a sandstone quarry for bench blasting operations. It was tried to present different perspectives for evaluation of blast fragmentation. Size distribution curves were created for each blast. KuzRam model provided successful results. Kuznetsov-Cunningham-Ouchterlony (KCO) model was useful especially for the fine size predictions. Capability of the models for fine, mean and coarse size predictions were evaluated in detail. Uniformity coefficients proposed by the models were examined. Chung & Katsabanis model was practically tested and a modification implemented for the studied quarry. Model validation was performed using ten different error metrics. Applicability of symmetric errors and scaled errors was investigated for evaluation of blast fragmentation. KuzRam model predicted mean fragment size with an error lower than three centimeters. The results of the modified Chung & Katsabanis model is quite promise.
PORTAL AND TUNNEL STABILITY RELATION IN A TUNNEL (ANKARA SİVAS HIGH SPEED RAILWAY PROJECTS, T3 TUNNEL)
DOI 10.30797/madencilik.792389 Ebu Bekir Aygar, Candan Gökçeoğlu
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One of the most frequent problems of tunnels built within the scope of transportation network projects, which has been developing rapidly in the recent years, is the stability of portal slopes. The failures occurring in the portal slopes sometimes result in stability problems in the tunnel and increase the problem. Within the scope of this study, the failure in the T3 Tunnel built within the scope of the Ankara-Sivas High Speed Train project, which is a typical example, is investigated. While the tunnel excavation was continuing, cracks occurred in the slope of the exit portal section and at the same time, failure occurred in the tunnel body. In the purpose of this study, both numerical analyzes and new support systems are evaluated to safely re-excavated the failed section, and the analysis of the necessary slope stability and the performance of the results are discussed In addition, in this study, the interaction of tunnel portal excavation and tunnel support systems in general is investigated and a procedure for such tunnel studies is proposed.
INVESTIGATION OF THE EFFECT OF RAW MATERIAL AND CLINKER GRINDABILITY ON ENERGY CONSUMPTION IN CEMENT PRODUCTION
DOI 10.30797/madencilik.792392 Abdul Vahap Korkmaz
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In this study, Hardgrove and Bond grindability tests were carried out on limestone, marble residue, clay stone, trass, gypsum and clinker. Grinding tests were performed on clinker samples belonging to two different facilities, and the fineness values were compared by grinding for 35 and 45 minutes. Cem I 42.5 R and Cem IV/B 32, R cements were ground in two identical mills in different industrial size plants and the fineness values of 32 μm, 45 μm and 90 μm were tested and compared. Unit energy consumption for different types of cement production in industrial mills is calculated and presented in comparison. Differences in the grindability of raw materials and the amount of energy spent in cement production were determined by experimental and industrial tests. The most easily ground material was clay stone, while the most difficult was clinker. As a result of HGI and Bond tests, it was confirmed that when cement is produced on an industrial scale with easy to grind materials, doped cements produced using trass, limestone and marble residues as substitutes for clinker, which is difficult to grind, their grinding energy needs are less than Cem I Portland cement and they can be ground more easily.
THE INVESTIGATION OF FINE COAL BENEFICIATION WITH TRIBOELECTROSTATIC SEPARATION
DOI 10.30797/madencilik.792395 Ergin Gülcan, T.Onur Dizdar, Gizem Kocausta, Özcan Y.Gülsoy
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The scope of this study is to design a triboelectric separation equipment and to investigate its use in the enrichment of the major coal samples in our country. Coal samples were obtained from four different operating plants in Tunçbilek and Soma regions for the use in experimental studies. Triboelectrostatic separation mechanism developed in Hacettepe University Mining Engineering Department was proved to provide up to 35 kV for the use in experimental studies. Following the preliminary tests regarding the required static load by friction, enrichment processes were carried out with coal samples. As a result of the experimental studies carried out with four different coal samples obtained from two different regions, it has been observed that with the triboelectrostatic separation, ash removal efficiencies exceeding 50% in fine grain sizes can be obtained depending on the structure of the coal.
AN EVALUATION OF WASTE UNDERSIZE PUMICE MATERIALS IN TERMS OF ENGINEERING CHARACTERISTICS IN CLAYEY SOILS
DOI 10.30797/madencilik.792401 Murat Kalkan, Can Erenson
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Population growth in developing countries and cities increases structuring and it increases the need for aggregate which is the basic building block of the construction industry. For this reason, quarries close to the settlements are opened and materials obtained from the quarries are mostly used in the construction sector but the remaining fine grained materials are considered as waste. In this study, the products obtained from pumice quarry located in Aksaray province and clayey soil in Avanos (Nevşehir) region were mixed in various quantities and soil properties of this mixture were investigated. As a result of fall cone method tests and modified proctor tests on these mixtures, waste fine graded pumice content in the clay samples increase, the liquid limit values and the maximum weight per unit of volume values decrease and the optimum water content values increase.
DETERMINING THE DRINKING WATER QUALITY IN SEVERAL RURAL SETTLEMENTS IN FERIZAJ MUNICIPALITY, KOSOVA
DOI 10.30797/madencilik.792404 Sadija Kadriu, Milaim Sadiku, Mensur Kelmendi, Donika Ibishi
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Suspicions of diverse pollution of groundwater in the villages of Dremjak, Talinoc i Muhaxherve, Softaj, Gërlicë and Varosh of the Ferizaj municipality motivated the investigation of empirical quality of the water wells from which the inhabitants of the villages provided drinking water. Considering that drinking water is the basic element for humans to live, its testing prior to consumption is necessary, therefore, this groundwater is the focus of this research. The samples were taken from the pumping stations, where underground waters were collected. The water was tested for organoleptic, physicochemical, and microbiological parameters, and during the analysis the classical analytical and instrumental methods were applied. The results of the analyses were compared with the Administrative Directive No. 16/2012 of Kosovo and the Instruction No. 98/83 of the EU, based on the standard values of the water quality consumed by humans. Both are in line with the standards of the World Health Organization for drinking water quality. It was determined that the groundwater in the respective five villages was contaminated with heavy metals (Fe, Pb, Mn, Cd and Ni). The water samples taken for analysis based on the underground map of the region show that the underground layers contain metals to some extent. Therefore, the presence of such metals in water is due to geological pollution. However, other organoleptic, physico-chemical and microbiological parameters are compatible with reference values.