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Öğe Determination of physical properties of carbonate rocks from P-wave velocity(SPRINGER HEIDELBERG, 2008) Kahraman, Sair; Yeken, TekinVelocity, density, porosity, void ratio, water absorption by weight and P-wave velocity tests were conducted on 14 different carbonate rocks. Strong correlations between P-wave velocity and all the physical properties of the rock were found. The relations follow a linear function. The equations developed were compared with others in the literature. Although it appears that the physical properties of the tested carbonate rocks can be estimated from P-wave velocity, the validity of the derived equations must be checked for other carbonate rocks as the equations given are likely to be specific to the test method and vary with rock type, degree of saturation and presence of bedding planes.Öğe Electrical resistivity measurement to predict uniaxial compressive and tensile strength of igneous rocks(INDIAN ACAD SCIENCES, 2010) Kahraman, Sair; Yeken, TekinElectrical resistivity values of 12 different igneous rocks were measured on core samples using a resistivity meter in the laboratory. The resistivity tests were conducted on the samples fully saturated with brine (NaCl solution) and the uniaxial compressive strength (UCS), Brazilian tensile strength, density and porosity values of the samples were determined in the laboratory. The test results were evaluated using simple and multiple regression analysis. It was seen that the UCS and tensile strength values were linearly correlated with the electrical resistivity. The correlation coefficients are generally higher for the multiple regression models than that of the simple regression models. It was concluded that the UCS and tensile strength of igneous rocks can be estimated from electrical resistivity. However, the derived relations are purely empirical and they should be checked for other igneous rocks. The effect of rock types such as sedimentary and metamorphic rocks on the derived equations also needs to be investigated.Öğe Electrical resistivity measurements to predict abrasion resistance of rock aggregates(SPRINGER, 2008) Kahraman, Sair; Fener, MustafaThe prediction of Los Angeles (LA) abrasion loss from some indirect tests is useful for practical applications. For this purpose, LA abrasion, electrical resistivity, density and porosity tests were carried out on 27 different rock types. LA abrasion loss values were correlated with electrical resistivity and a good correlation between the two parameters was found. To see the effect of rock class on the correlation, regression analysis was repeated for igneous rocks, metamorphic rocks and sedimentary rocks, respectively. It was seen that correlation coefficients were increased for the rock classes. In addition, the data were divided into two groups according to porosity and density, respectively. After repeating regression analysis for these porosity and density groups, stronger correlations were obtained compared to the equation derived for all rocks. The validity of the derived equations was statistically tested and it was shown that all derived equations were significant. Finally, it can be said that all derived equations can alternatively be used for the estimation of LA abrasion loss from electrical resistivity.Öğe Empirical methods to predict the abrasion resistance of rock aggregates(SPRINGER HEIDELBERG, 2007) Kahraman, Sair; Gunaydin, OsmanThe possibility of predicting the Los Angeles ( L. A.) abrasion loss from the Schmidt hammer, point load and porosity tests was investigated using 9 igneous, 11 metamorphic and 15 sedimentary rocks with L. A. values ranging from 10 to 76%. Regression analysis indicated a strong correlation (r(2) = 0.72) between L. A. abrasion loss and point load and a good correlation (r(2) = 0.62) between L. A. abrasion loss and Schmidt hammer value. When the samples were divided according to porosity (n < 1% and n > 1%), stronger correlations were obtained, especially for the point load index. The predictions from the Schmidt hammer results were not as good but within acceptable limits.Öğe Estimating specific energy from the brittleness indexes in cutting metallic ores(South African Institute of Mining and Metallurgy, 2016) Çomaklı, Ramazan; Kahraman, Sair; Balcı, Cemal; Tumaç, DenizSpecific energy (SE) is a very useful parameter for assessing rock excavation by machine. Predicting the SE from the brittleness will be practical, especially for preliminary studies, due to the fact that determining the SE from cutting tests is difficult and expensive. In this study, the predictability of the SE from different brittleness concepts was investigated for metallic ores such as chromite, haematite, galena, and smithsonite. Uniaxial compressive strength, Brazilian tensile strength, impact strength, and small-scale cutting tests were carried out in the laboratory. The SE values were calculated from the cutting tests and correlated with three different brittleness concepts. A significant correlation could not be found between the SE and the brittleness B-3 (the ratio of compressive strength minus tensile strength to compressive strength plus tensile strength). However, strong correlations were found between the SE and the both brittleness B-5 (the product of percentage fines in the impact strength test and compressive strength) and brittleness B-8 (half of the product of compressive strength and tensile strength). The validations of the derived equations were also checked. It is concluded that the SE in ore cutting can be reliably estimated from the brittleness concepts B-5 and B-8.Öğe Evaluating the grinding process of granitic rocks using the physico-mechanical and mineralogical properties(Chulalongkorn Univ, Metallurgy & Materials Science Research Inst, 2019) Kahraman, Sair; Ucurum, Metin; Yogurtcuoglu, Emine; Fener, MustafaGranitic rocks are sometimes ground for different purposes. Predicting the mean particle size (d(50)) is useful for planning and cost estimation of purposes. In order to investigate the possibility of predicting the d(50) of ground rock from the physico-mechanical rock properties, six different granites were tested in the laboratory. First, the d(50) values were correlated with the corresponding physico-mechanical properties. The simple regression analysis showed that there were no good correlations between the d(50) and the physico-mechanical properties. Then, the multiple regression analysis was carried out and strong prediction equations were developed. It was also shown that the dominant parameter in grinding was the abrasive mineral content of rock. It is concluded that the d50 of granites can be predicted from the derived multiple regression equations especially for preliminary investigations. The developed estimation equations including index test values are especially useful since they are easy to use.Öğe Mikrodalgaya Maruz Bırakmanın Granitik Kayaçlarının Mekanik Özellikleri Üzerindeki Etkilerinin Araştırılması(2018) Kahraman, Sair; Fener, MustafaKaya delme ve kesme teknolojisi son yüzyılda hızla gelişmiştir. Ancak, çok sert kayaçların delinmesi ve kesilmesinde düşük ilerleme hızı ve yüksek matkap ve keski aşınması gibi problemler bulunmaktadır. Çok sert kayaçların delinmesi veya kesilmesi esnasında ilerleme hızını arttırmak ve aşınmayı azaltmak amacıyla, son zamanlarda mikrodalga destekli kaya parçalama gibi bazı yenilikçi yöntemler üzerinde yapılan çalışmalar dikkat çekmektedir. Mikrodalgaya maruz bırakmanın granitik kayaçların mekanik özellikleri üzerindeki etkileri konusundaki çalışmalar yeni ve sınırlıdır. Bu nedenle, bu alanda araştırılacak birçok eksiklik bulunmaktadır. Bu çalışmada, dokuz farklı granitik kayacın mekanik özellikleri üzerinde mikrodalgaya maruz bırakmanın etkileri araştırılmıştır. Mikrodalgaya maruz bırakmanın etki derecesi üzerinde mineral içeriğinin etkileri de incelenmiştir. Önce her kayaç cinsi için tek eksenli basınç dayanımı ve Brazilian çekme dayanımı deneyleri yapılmıştır. Ayrıca, her kayacın mineral içerik ve yüzdeleri belirlenmiştir. Daha sonra, dayanım deneyleri için hazırlanan ikinci grup numuneler mikrodalgaya maruz bırakılmışlardır. 1kW, 2kW ve 6kW mikrodalga güçleri 60s? den 420s? ye kadar değişen sürelerde uygulanmıştır. Sonra, mikrodalgaya maruz bırakılmış numuneler üzerinde dayanım deneyleri yapılmıştır. Mikrodalgaya maruz bırakılan her numunenin yüzey sıcaklığı da kızılötesi termometre ile ölçülmüştür. Ayrıca, mikrodalgaya maruz bırakmanın mikroskopik etkilerini görmek amacıyla mikrodalgaya maruz bırakılmış çekme dayanımı numunelerinden ince kesitler hazırlanmıştır. Deney sonuçların değerlendirilmesi, mikrodalgaya maruz bırakma sonrası ısı derecesinin ve dayanım kaybının her kayaç içi farklı olduğunu göstermiştir. Isınma derecesi ve dayanım kaybı genellikle artan mikrodalga gücü ve artan maruz bırakma süresi ile artmaktadır. Bir numunennin ısınma derecesi ve dayanım kaybı onun mineral içeriğine bağlıdır. Mikrodalgaya maruz bırakılan numunelerin ince kesitlerinin analizi, artan ısıya bağlı olarak mineral tane sınırlarının genişlediğini, mikroçatlakların geliştiğini ve minerallerin alterasyona uğradığını göstermiştir. Mikrodalgaya maruz bırakmanın granitik kayaçların mekanik ve mineralojik özellikleri üzerinde önemli etkileri olduğu sonucuna ulaşılmıştır. Ancak, konuyla ilgili ileride daha detaylı çalışmalar yapılmalıdır.Öğe Performance prediction of roadheaders in metallic ore excavation(PERGAMON-ELSEVIER SCIENCE LTD, 2014) Comakli, Ramazan; Kahraman, Sair; Balci, CemalUsing mechanical miners such as roadheaders may be a solution to increase the production rate and to decrease the costs in metallic mines. In this study, the performance prediction and cutter consumption of roadheaders were investigated for the eight different ore types. Small-scale linear cutting tests, Cerchar abrasivity tests and physico-mechanical tests were carried out on the ore samples collected from the site. The instantaneous cutting rates of a selected roadheader were calculated using specific energy (SE) values and compared to the previous models. The amount of cutter consumption was also calculated for each ore type and it was seen that the estimated cutter consumption values for the tested ores are generally lower than the proposed economical upper limit. Since only the performance prediction and cutter consumption of roadheaders were investigated for the excavation of ores in the current study, analyzing all mining operations is necessary for the adaptation of roadheader excavation to a mine. Simple and multiple regression models were also derived for the estimation of SE from the ore properties. A significant practical model including the Schmidt hammer value and density of ores was produced from the multiple regression analysis. This regression model can be reliably used for the estimation of SE especially for the preliminary studies. (C) 2013 Elsevier Ltd. All rights reserved.Öğe Performance prediction of roadheaders in metallic ore excavation (vol 40, pg 38, 2014)(PERGAMON-ELSEVIER SCIENCE LTD, 2014) Comakli, Ramazan; Kahraman, Sair; Balci, Cemal[Abstract Not Available]Öğe Predicting the noise level during sawing of carbonate rocks from the P-wave velocity(International Commission for Acoustics (ICA), 2019) Kahraman, Sair; Delibalta, M. Suat; Comakli, RamazanNoise affects humans both physically and psychologically, whose impacts vary from person to person. Block cutting machine is one of the most important noise sources in the stone processing plants. This study investigates the predictability of the noise level generated during sawing of carbonate rocks from the P-wave velocity. First, the P-wave velocities of rock samples were measured in the laboratory. Then, the core samples were cut by an automatic cutting machine with diamond saw in the laboratory and noise levels were measured. A strong linear correlation was found between the noise levels and the P-wave velocity. After including the densities of the samples to the analysis, the correlation coefficient was increased significantly. It is concluded that the noise level of carbonate rocks can be estimated using the derived equations from the P-wave velocity. The laboratory noise level can be converted to the site noise level using a conversion factor. © 2019 Proceedings of the International Congress on Acoustics. All rights reserved.Öğe Predicting the noise level in rock sawing from the physico-mechanical and mineralogical properties of rocks(ELSEVIER SCI LTD, 2016) Kahraman, Sair; Delibalta, Mahmut S.; Comakli, Ramazan; Fener, MustafaMillions of employees in the World are exposed to noise at work. Block cutting machine is one of the most important noise sources in the stone processing plants. In this study, the predictability of the noise from the block cutting machines in the stone processing plants was investigated by using the physico-mechanical and mineralogical properties of rocks. The noise levels of some block cutting machines were firstly measured during the cutting of the three different rocks. Then, the core samples of the same rocks were cut by an automatic cutting machine in the laboratory and the noise levels were measured. A conversion factor was obtained by dividing the site noise levels by the laboratory noise levels. Then, nineteen different rocks were cut by the automatic cutting machine in the laboratory and the noise levels were measured. Strong correlations were found between the laboratory noise level and the rock properties. The noise level increases with increasing rock strength, abrasive mineral content, and density. However, increasing porosity decreases the noise level. It was concluded that the laboratory noise level for a new rock type to be cut can be estimated using the derived relations. Then, the laboratory noise level can be converted to the site noise level using the derived conversion factor. (C) 2016 Elsevier Ltd. All rights reserved.Öğe Reply to the discussion by A. Sawangsuriya and D. Fratta on "Correlations between P-wave velocity and Atterberg limits of cohesive soils"(CANADIAN SCIENCE PUBLISHING, NRC RESEARCH PRESS, 2006) Fener, Mustafa; Kahraman, Sair; Bay, Yakup; Gunaydin, Osman[Abstract Not Available]Öğe The drillability assessment of rocks using the different brittleness values(PERGAMON-ELSEVIER SCIENCE LTD, 2011) Yarali, Olgay; Kahraman, SairThe brittleness is a fundamental rock property and effective in drilling and rock excavation. Knowing the relations between the drillability and the brittleness will help the rock engineers. For this reason, to investigate the relations between the drilling rate index (DRI) and the different brittleness values, 32 different rock types were tested in the laboratory. Uniaxial compressive strength and tensile strength were determined for the brittleness calculations. The brittleness of B-3 (the ratio of compressive strength minus tensile strength to compressive strength plus tensile strength), and the brittleness of B-8 (the half of the product of compressive strength and tensile strength) were calculated from the test results. In addition, Sievers' J-miniature drill test and the brittleness test were carried out and DRI values were calculated. Then, B-3 and B-8 were correlated with DRI values. A good correlation between DRI and the brittleness of B-3 could not be found. However, a strong exponential relation between DRI and the brittleness of B-8 was found. Comparing the results with the literature showed that there was an agreement between this study and previous studies. It can be concluded that B-8 can be used for the assessment of rock drillability. Crown Copyright (C) 2010 Published by Elsevier Ltd. All rights reserved.Öğe The effect of mineralogy on the microwave assisted cutting of igneous rocks(Springer Heidelberg, 2022) Kahraman, Sair; Sarbangholi, Faraz S.; Balci, Cemal; Fener, Mustafa; Karpuz, Ceyhun; Comakli, Ramazan; Unver, BahtiyarHard rocks can be excavated difficultly by some mechanical miners such as roadheaders. Tunnel boring machines (TBMs) can excavate hard rocks, but the cost is high due to low advance rate and high tool wear. The difficulties in hard rock excavation can be overcome by exposing hard rocks to microwave energy while cutting. This study investigates influence of mineralogy on the microwave assisted cutting of igneous rocks. The normal and cutting forces were measured during the cutting tests, and the specific energy values were calculated. The optimum specific energy (SEopt.) values reduce quite steadily with the increasing microwave power. The SEopt. of some tested crystalline rocks first increases at the low power (3 kW) and then decreases at the high power (6 kW). The losses in the SEopt. range from 22.5 to 38.7% at the power of 6 kW. The equations were also developed for the estimation of the SEopt. loss. Concluding remark is that the same rock types may be affected differently by microwave energy because of the different mineral types and percentages, and thus they behave diversely under cutting tests. The derived equations will be useful for the prediction of the SEopt. loss due to the microwave treatment.
