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Öğe A new model for comminution behavior of different coals in an impact crusher(Taylor and Francis Inc., 2014) Umucu, Yakup; Deniz, Vedat; Çayırlı, SerkanIn this study, breakage behavior of three different coals in a laboratory impact crusher was investigated. The laboratory impact crusher carrying three rows of hammers is rotating at 2,840 rpm driven by a 1.1 kW motor. In the evaluation of crushers, t-family curves obtained from pendulum and drop weight test methods are frequently used. It is a known fact that there are many difficulties and problems in these tests. In this study, a new model was developed by t-family value evaluation and Bond grindability approach and the model was tested. As a result, the validity of the model was proved by a high regression value (r2 = 0.945). © Copyright Taylor & Francis.Öğe An evaluation of a modified product size distribution model based on t-family curves for three different crushers(Oficyna Wydawnicza Politechniki Wroclawskiej, 2013) Umucu, Yakup; Deniz, Vedat; Ünal, NazmiCrushing is a process which is widely used in mineral processing plants, cement factories, aggregates plants and some other industrial plants. Specific fracture energy of the particles is not the only fundamental property that is important: the particle strength also plays a significant role in determining the overall comminution properties of the material. In the drop weight test, a known mass falls through a given height onto a single particle providing an event that allows characterization of the ore under impact breakage. It is known that there are many difficulties and problems in the drop weight and twin pendulum test methods such as being laborious, requiring long test time and requiring a special apparatus. In this study, breakage behavior of slag in different laboratory crushers was investigated. A new size distribution model equation was developed by a t-family value evaluation approach, and the validity of equation was tested.Öğe Application of statistical process control for coal particle size(Taylor and Francis, 2013) Deniz, Vedat; Umucu, YakupIn this article, variations in particle sizes (F50 and P 50) obtained from feeding and ground coals in a vertical roller mill of AS Cement Factory (Turkey) were investigated using control charts and process capability analysis. From results of calculations, the control charts mostly indicated that the variations in particle sizes of the feeding and ground coals are outside the control and specification limit and are not statistically stable. Additionally, a viewpoint was that the process capabilities were inadequate. The reason for this might be the different feeder and bin discharge problems of coal and the careless behaviors of laborers. © 2013 Taylor and Francis Group, LLC.Öğe Estimation of the bond grindability index from the sink-float test data of two different particulate pumices(Taylor and Francis, 2012) Deniz, Vedat; Umucu, Yakup; Çayırlı, SerkanIn this study, equations for estimating the Bond grindability index by the sink-float test data of pumice were developed. Primarily, the cumulative weight and porosity content of the floating fraction were determined for two different pumice samples in all relative densities. Then, grindability of the pumice samples was determined for its constituent specific gravity fractions. Though the grindability of the constituent specific gravity fractions of both the pumices varies in a systematic manner, certain differences, it can be observed in the variation pattern between the two pumices. These differences included easy washability and moderate difficult washability characteristic pumices. The relationships between the Bond grindability and relative densities and between the Bond grindability and porosity were stated as simple equations, and the calculated values from equations were compared with the experimental results. Finally, the float-sink test results can be stated by simple equations relating to the Bond grindability value. The Bond grindability (Gbg) was easily measured by carrying out sink-float tests, and by measuring the constituent relative density fractions and porosity content. © 2012 Copyright Taylor and Francis Group, LLC.Öğe Flocculation of fine particles in ceramic wastewater by using polymers(Polish Mineral Engineering Society, 2014) Deniz, Vedat; Umucu, YakupThe clarification of industrial wastewaters by solid-liquid separation techniques and the removal of suspended particles are the problems of growing environmental consciousness. However, there appears to be very limited number of studies reported in the literature to investigate the flocculation and settling properties of ceramic wastewaters. The efficiency of solid/liquid separation may be greatly improved by the application of synthetic polymeric flocculants, particularly in mineral processing plant where sedimentation, filtration and centrifugation processes are extensively used. In ceramic plants, the water used in ceramic processing is contaminated with suspended quartz, feldspar and associated clay particles, which results in a so-called wastewater problem which have to be dealt with from an environmental point of view. In this study, sedimentation of ultrafine particles from ECE Ceramic Co. (Çorum/Turkey) ceramic wastewater sample was investigated using three anionic polymeric flocculants (Superfloc A-130, Superfloc A-100 and Enfloc 330A). The performances of the flocculant in the experimental studies were assessed with the change in the interfaces height during sedimentation resultant. The best performance was obtained Superfloc A-130. At the dose of 60 g/t for A-130, the settling rate was shorter than 60 seconds.Öğe Interrelationships between the bond grindability with physicomechanical and chemical properties of coals(Taylor and Francis, 2013) Deniz, Vedat; Umucu, YakupIn this research, different techniques for the estimation of Bond grindability (Gbg) values of coals are studied. Data from ten sub-bituminous coals from Turkey are used by featuring physicomechanical (ISI, Is, and FD) and eight chemical coal parameters, which include proximate analysis (moisture, ash, volatile matter, fixed carbon, and calorie). Linear and multivariable linear regression techniques are used for predicting the Gbg values for the specified coal parameters. Results indicate that a multivariable linear regression gave the most accurate Gbg prediction than simple regression in the estimation process. © 2013 Taylor & Francis Group, LLC.Öğe Investigation of breakage behavior of different mineralogical and morphological characteristic pumices(2011) Deniz, Vedat; Çayırlı, Serkan; Umucu, YakupThe objective of this study is to analyze dry grinding behavior of four different pumices in terms of Bond grindability value, selection and breakage parameters values. For this purpose, firstly, Bond grindability test were made for four pumices. Then, eight different mono-size fractions for each of pumices were carried out between 1.7 and 0.106 mm formed by a ?2?2 sieve series, and ground batch wise in a laboratory ball mill for determination of breakage parameters. Finally, S i and B i,j equations were determined from the size distributions at different grinding times, and the model parameters (S i , a T , ?, ?, ? and ?j?j) were compared for four different pumice samples.Öğe Modeling of grinding process by artificial neural network for calcite mineral(IEEE, 2011) Umucu, Yakup; Çağlar, Mehmet Fatih; Gündüz, Lütfullah; Bozkurt, Volkan; Deniz, VedatThe grindability properties of calcite sample belong to Afyonkarahisar region were investigated at batch grinding conditions based on a kinetic model. The obtained kinetic model parameters were used to estimate the product size distribution by artificial neural networks (ANN). Then, the experimental and neural network prediction results are compared. © 2011 IEEE.Öğe Prediction of the bond grindability index from the sink-float test data of coals(Taylor and Francis, 2013) Deniz, Vedat; Umucu, Yakup; Çayırlı, SerkanIn this study, a relation for calculating the Bond grindability by the sink-float test data of coals was studied. Primarily, sink-float tests for three coal samples were made. Secondly, the cumulative weight and ash content of the floating fraction were determined for three different coal samples in all relative densities tested. Then, grindability of the coal samples were determined for its constituent specific gravity fractions. The relationships between the Bond grindability and relative densities have been stated as simple polynomial equations and the calculated values from equations have been compared with the experimental results. Finally, the float-sink test results can be stated by simple equations relating to the Bond grindability value. The Bond grindability (Gbg) was easily determined by carrying out sink-float separation. © 2013 Taylor & Francis Group, LLC.Öğe The effect of ball type in fine particles grinding on kinetic breakage parameters(Polish Mineral Engineering Society, 2015) Umucu, Yakup; Deniz, VedatIn the study, the effect of different grinding media on breakage parameters was investigated. Ceramic and steel balls were used as the grinding media. It was observed that the grinding of ignimbrite obeyed first-order breakage kinetics law in the case of ceramic and steel balls. Breakage rates were higher for steel ones comparing to ceramic balls. Furthermore, it was found that the primary breakage distribution function depends on the feed size (i.e., non-normalized), and depends on the different grinding media. The effect of grinding time on the product particle size distribution has also been investigated.Öğe The effects of ball types on breakage parameters of barite(Polish Mineral Engineering Society, 2014) Umucu, Yakup; Altıniğne, Mehmet Yılmaz; Deniz, VedatSpherical balls are the dominant media shape used in the tumbling mills. However spherical balls wear into nonspherical fragments as a result of breakage due to impact and different wearing mechanisms inside the mill. Thus at any one time a mill charge is a mixture ranging from larger spherical balls to worn irregular. There is not much work done to assess the impact of balls on mill performance. An experimental work was made in this study about the effect of media shape on grinding of barite. Existing studies focus on grind performance in ball mills. The absolute fineness of the ball type is important factors for the optimal operation of a ball mill. Therefore, the effects on breakage kinetics of the ball type were investigated on the barite powder at batch grinding conditions based on a kinetic model. For this purpose, firstly, four different fine mono-size fractions were carried out between 0.106 and 0.045 mm formed by a?2 sieve series. Then, Si and Bi, j equations were determined from the size distributions at different grinding times, and the model parameters were compared for three different ball type. The results of tests, the effect of ball type on the grinding were found to be different than other investigators regarding some results.Öğe The evaluation of grinding process using artificial neural network(Elsevier, 2016) Umucu, Yakup; Deniz, Vedat; Bozkurt, Volkan; Çağlar, Mehmet FatihBall milling has been the subject of intensive research for the past few decades. It is indeed the most encountered mineral processing operation of size reduction. Known as the most energy inefficient process, focus has mainly been on ways of reducing the energy consumption incurred by the operation. There are programs for the computer design of mineral processing circuits, and these programs contain computer simulation models for ball mill design. These models need the input of characteristic breakage parameters for the mineral of interest and these are often determined in a small size laboratory ball mill and scaled up by the program to the conditions of a full-scale ball mill. Models and simulators have been used for plant technical analysis since 1970. Some of these models and simulators were developed for mineral processing operations, whereas some were dedicated to mineral processing operations. The prominent work for the mineral processing applications includes JKSimMet, MODSIM © and its derivatives. A neural network is able to learn complex relationships between related variables and therefore has been widely used as a tool for process modeling. It consists of many simple parallel processing units (called "neurons"), which can resemble the architecture of the human brain, and thus is capable of learning arbitrary nonlinear mappings between noisy sets of input and output factors. The grindability properties of the calcite sample belonging to the Mu?la region were investigated at batch grinding conditions based on a kinetic model. The obtained kinetic model parameters were used to estimate the product size distribution by artificial neural networks (ANN). Then, the experimental and neural network prediction results were compared. © 2015 Elsevier B.V.Öğe The relationship between cement quality and separation cut size(Polish Mineral Engineering Society, 2015) Umucu, Yakup; Deniz, Vedat; Saraç, M. Fahri; Kuzgun, A. ErkanCement is prepared by firing a mixture of raw materials, one of which is mainly composed of calcium carbonate and the other of aluminium silicate. The most familiar materials answering to this description are limestone and clay, both of which occur in nature in a great number of varieties. Marls, which are a mixture of clay and shales, are also common raw materials for cement. The production of cement is an energy-intensive process. The typical energy consumption of a modern cement plant is about 90-120 kWh per ton of produced cement. The service properties of cement such as workability and strength development are affected not only by the chemical and mineralogical composition but also to a great extent by the fineness and particle size distribution of the cement produced; in practice often only the strength development of cement is of primary interest. Yet the effect on workability is just as important. Moreover, the surface area and granulometric parameters may also directly or indirectly affect the frost resistance and other durability-related properties of concrete. There are process engineering options for controlling fineness and particle size distribution of the cement by changing the mode of operation of the mill and the separator. This paper describes a study of the relationship between cement strength and separation cut size (d50). The separation cut size (d50) of air separator products obtained by different days was ascertained by using particle size analysis. It was found that the cement fineness and separation cut size (d50) are very effective on the strength of cement.
