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A new binder in production of water-resistant briquettes from bituminous coals: Co-polymer binder
(Taylor and Francis Inc., 2016) Deniz, Vedat
Briquetting could be a solution to economic and environmental problems regarding fine coals. However, briquettes that are formed using molasses disintegrate in water and create problems. Providing water resistance to briquette, bitumen and asphalt are illegally used, however they generate more air pollution. In order to resolve this negative situation, a new binder with a co-polymer origin, Mowilith-VDM, is tested for briquetting of bituminous fine coals. The results of tests have shown that class I type (TSE, 1996) water resistance briquette can be produced using the co-polymer binder percent of 8, a drying temperature of 100°C, a drying time of 15 min, and a pressure load of 29.5 MPa. © 2016 Taylor & Francis Group, LLC.
A new model for comminution behavior of different coals in an impact crusher
(Taylor and Francis Inc., 2014) Umucu, Yakup; Deniz, Vedat; Çayırlı, Serkan
In 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.
A new size distribution model by t-family curves for comminution of limestones in an impact crusher
(Elsevier, 2011) Deniz, Vedat
In the evaluation of crushers, t-family curves obtained from single particle test methods are frequently used. It is known that there are many difficulties and problems in these tests. In this study the breakage behaviour of three different limestones in an impact crusher was investigated. A new size distribution model was developed by t-family value evaluation and Bond work index approach. As a result, the validity of the equation was proved by a high regression value (r2 = 0.88). © 2010 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.
A study on the effect of ball diameter on breakage properties of clinker and limestone
(The Council of Scientific & Industrial Research, 2012) Deniz, Vedat
Effect of ball diameter has been studied on the limestone and clinker samples under batch grinding conditions based on a kinetic model. Firstly, eight different mono-size fractions between 1.7 mm and 0.106 mm formed by a root 2 sieve series have been prepared. Then, S-i, and B-ij, equations are determined from the size distributions at different grinding times, and the model parameters (S-i, a(T), alpha, gamma and phi(j)) are compared for four different ball diameters (41, 25.4, 20 and 9.5 mm). The results show that the study on the effect of ball diameter on the grinding gives more different results than other investigations. The variation in specific rate of breakage with feed size is independent of ball diameters and kind of materials.
A study on the effects of coal feed size and coal type on the performance of a laboratory jaw crusher
(Taylor and Francis, 2014) Deniz, Vedat
In this study, the effects at the three different coal size fractions on the five different characteristic coal samples depend on the performance of a crusher in the laboratory. Thus, a jaw crusher was investigated. Based on the results of the investigation, it was found that there is a great influence of coal feed size and coal type on crushing performance. Determination of crusher type can be emphasized more important from necessary tests instead of habits and traditions. Copyright © 2014 Taylor & Francis.
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, Nazmi
Crushing 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.
An investigation on the effects of the ball filling on the breakage parameters of natural amorphous silica
(Elsevier B.V., 2016) Deniz, Vedat
The effects of ball filling on the selection (Si) and breakage functions (Bi,j) for the natural amorphous silica were investigated in this paper. At four levels (20%, 30%, 40% and 50%) of ball filling, the selection functions and breakage functions were determined by one-size-fraction tests. The selection function was found be quite effective with increasing ball filling for smaller particle size, but it was found to show differently for larger particle size. The breakage functions obtained by direct measurement were studied. When the ball filling was high, the breakage function was appeared to be higher for the natural amorphous silica. The results of tests, the effect of ball filling on the breakage parameters were found to be different than previous studies regarding some results. Therefore, it has appeared that the grinding kinetics for each material must be evaluated in order to lower the energy costs in grinding process. © 2016 The Society of Powder Technology Japan
Application of multiple linear regression (MLR) analysis for concentration of chromite tailings by the flotation
(Oficyna Wydawnicza Politechniki Wroclawskiej, 2020) Deniz, Vedat
In this study, the concentration of chromite minerals by amine flotation of a chromite tailing (slime) with content 23.84% Cr2O3 from Yesilova-Burdur (Turkey) was investigated. In experimental studies, firstly, some operating parameters of the rougher flotation observed for a low-grade chromite tailing were investigated. Secondly, multiple linear regression (MLR) analyses were performed to determine the effects of some operating parameters on the performance of the rougher amine flotation. From the experimental results, multiple linear regression equations were developed to predict the recovery and grade of the chromite concentrate, and the regression coefficients between experimental and predicted values were found to be quite good (R-2 values of 0.772 and 0.917, respectively). Additionally, it was found that the conditioning time and low pH value using H2SO4 showed an important effect on the recovery and the grade of the chromite concentrate.
Application of statistical process control for coal particle size
(Taylor and Francis, 2013) Deniz, Vedat; Umucu, Yakup
In 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.
Comparison with some porous materials and the effects of powder filling on breakage parameters of diatomite in dry ball milling
(Taylor and Francis, 2011) Deniz, Vedat
In this study, a comparison of breakage parameters with some porous materials (pumice, trass, and amorphous silica) and the effects on breakage kinetics of powder filling of diatomite were investigated on at batch grinding conditions. For this purpose, first, standard Bond grindability tests were performed for four porous samples. Second, eight different mono-size fractions of all samples were carried out between 1.7mm and 0.106mm formed by a a?2 sieve series. Then, Si and Bi,j equations were determined for the size distributions at different grinding times, and the model parameters (Si, aT, ?, ?, ?j, and ?) were tested for four different porous materials. Finally, model parameters were discussed for four different powder filling (3.5, 7, 10.5, and 14%) of diatomite samples. From the results of test, the validity of the relationships between Bond grindability and breakage parameters has been not confirmed with good correlation coefficients. The reason of this negative result could be attributed to different of the geological origin of porous materials. In addition, the results of the effect of powder filling on the grinding were found different than other investigators. Copyright © Taylor & Francis Group, LLC.
Comparisons of dry grinding kinetics of lignite, bituminous coal, and petroleum coke
(Taylor and Francis, 2013) Deniz, Vedat
The objective of this study was to analyze dry grinding kinetics of three different solid fuels in terms of selection and breakage distribution functions values using a batch laboratory ball mill. For this purpose, first, standard Bond grindability tests were made for three different fuel samples. Second, experiments were carried out with eight different mono-sizes between 1.7 and 0.106 mm formed by a ?2 sieve series fraction. Then, parameters of Si and B i,j equations were determined from the size distributions at different grinding times. Finally, the kinetic model parameters (Si , aT , ?, ?, ?, and ? j ) were compared for three different fuel samples, and the relationship between proximate analysis values (ash, moisture, etc.) with the Bond grindability value (Gbg ) and breakage parameters were examined. From the results of the test, the validity of the relationships between Bond grindability and proximate analysis has been not confirmed with good correlation coefficients. The reason for this negative result could be attributed to a difference of the geological origin of solid fuels. However, relationships between breakage parameters of grinding kinetic and proximate analysis values of solid fuel samples were obtained for ? value. Additionally, it was found that the bituminous coal was easier to grind than lignite and petroleum coke, taking into account the quite different values of the model parameters. However, petroleum coke was given finer than other fuel in respect to finer size fraction.
Computer simulation of product size distribution of a laboratory ball mill
(Taylor and Francis Inc., 2011) Deniz, Vedat
In this study, a computer simulation of a suitable matrix notation of the Broadbent and Callcott grinding model was written. First, a chromite sample was ground in the laboratory type batch ball mill at different grinding times, with different particle size distributions and different capacities. Second, elements of the matrix for computer simulation were found and a ''milling matrix'' was formed. Third, particle size distributions were predicted by computer simulation for the whole test. Finally, a relationship between the computer simulation predicted by dates and experimental results was established, with a good correlation within the limits of mean error values.
Dewatering of barite clay wastewater by inorganic coagulants and co-polymer flocculants
(Oficyna Wydawnicza Politechniki Wroclawskiej, 2015) Deniz, Vedat
This work is focused on dewatering of barite-containing clay waste from a barite beneficiation plant by coagulation and flocculation to enhance the dewatering rate and recycling of process water. A flocculation performance of co-polymers (Superfloc A-130 and A-100) was compared with coagulants (Al2SO4 18H2O, CaCl2 and FeCl3 6H2O). The best results were obtained with an anionic co-polymer, i.e. Superfloc A-130. The settling rate increased 635-fold in the case of using anionic co-polymer Superfloc A-130 in comparison with the natural settling rate of the same wastewater. In laboratory tests, an optimum thickener design was developed for the barite clay wastewater. In this paper, sedimentation studies on the barite clay wastes are presented for the first time, both as the laboratory studies and industrial applications.
Effects of mill speed on kinetic breakage parameters of four different particulate pumices
(Taylor and Francis, 2013) Deniz, Vedat
In this study, the effect of mill speed was investigated on different particulate pumice samples at batch grinding conditions based on a kinetic model. For this purpose, 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 ) were compared for three different mill speed (fraction of mill critical speed; 65%, 75%, and 85%).The effect of fraction of mill critical speed (?c) on the grinding for model parameter a T found to be different for four different pumices. Additionally, in this study it was found that optimum grinding occurs at ?c = 85% for all pumice samples, in contrast to the 75% of critical speed of the ball mill.
Effects of two important parameters on capacity of a laboratory Jaw crusher of different coals: Choke feed level and effective reduction ration
(Taylor and Francis, 2011) Deniz, Vedat
In this study, the effects of three different choke feed level (1/1, 1/2, and 1/4) and four different effective reduction ratios (2.5, 5, 10, and 20) depend on the capacity of the crusher of the three different characteristic coal samples in a laboratory Jaw crusher were investigated. Instead of the one-stage reduction, the capacity of the jaw crusher with a three-stage reduction has been an increase of between 38% and 82% according to coal type. Additionally, size distributions of products become more homogeneous. In addition to coal types, choke feed levels and reduction ratios are one important factor at the selection of crusher type. Copyright © Taylor & Francis Group, LLC.
Estimation of the Bond grindability index from chemical analysis values and modulus of mixture of raw material of marls
(ICE Publishing Ltd., 2012) Deniz, Vedat
In this study, the relationships between Bond grindability index (G bg) and chemical constituents were investigated on marl samples from the AS cement factory (Burdur/Turkey). First, standard Bond grindability tests were carried out for marl samples. Then, chemical analysis values were performed for six different marl samples. Second, the modulus of mixture of raw materials (lime saturation factor, cementation index, saturation factor, cementation index, alumina modulus, lime and silica modulus, hydraulic modulus, silica modulus) was calculated. Finally, the relationships between the Bond grindability (G bg) with chemical analysis values (calcium oxide, silicon dioxide and loss on ignition) and modulus of a mixture of raw materials were examined. The validity of the obtained relationship equations have been confirmed with correlation coefficients (r 2) of as high as 0.954, outside silica modulus through a simple regression analysis of marl samples. From these relationships, the Bond grindability index of marl samples can be determined with good accuracy. © 2012 Thomas Telford Ltd.
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, Serkan
In 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.
Evaluation by multi gravity separator (MGS) of a low grade chromite tailing from Yesilova-Burdur (Turkey)
(Polish Mineral Engineering Society, 2019) Deniz, Vedat
In this study, concentrability by a Multi-Gravity-Separator (MGS) of the chromite tailings with content 23.84% Cr2O3 from Yeşilova-Burdur (Turkey) is investigated. Mineralogical analyses showed that the chromite tailings contain chromite and serpentine which formed as a result of alteration of serpantine group minerals such as olivines, chrysotile and talc. The tailings generated from chromite beneficiation plants in Turkey are generally concentrated by slime tables (Deister shaking tables) for producing the desirable saleable grade. However, slime tables are concentrating with low recovery for chromite minerals which are very fine particle size. MGS is an efficient method for separation of minerals by gravity at very fine particle size. In experimental studies, the effects of feed rate, washwater rate, drum speed and tilt angle, which are important for operating parameters of MGS observed for the low grade chromite tailings were investigated. As a result of the experimental studies performed, it was obtained a concentrate with saleable chromite grade and recovery from the tailings which is having size fraction under 0.075 mm
Evaluation of Grindability Behaviors of Four Different Solid Fuels Blending by Using the Hardgrove Mill
(Polish Mineral Eng Soc, 2019) Deniz, Vedat
Grindability measurements are widely used in mineral and coal processing industry to determine resistance of materials to comminution. Grindability measurement as testing methods can be divided into two general categories; the Bond and the Hardgrove grindabilities. Grinding characteristics of the mineral or coal blending have been studied by several researchers over many years and a wide range grinding variables has been investigated. In this study, because of the simplicity and the potential usage of the method for the determination of the grindability of coals and their blending in a comparative scale, a Hardgrove mill were used to investigated the grinding behavior of four different solid fuels and their blending. Grindability of four different solid fuels such as petroleum coke, coke coal, lignite and bituminous coal and their binary, ternary and quaternary blending were investigated by the Hardgrove grindability test. The test results indicated that determine the existence of a very good relation between the Bond and the Hardgrove grindability of the fuels, and relationship between experimental and calculated HGI values of the fuels blending were also shown as a very good. However, there is not obtain a good relation between proximate analysis results of the solid fuels and HGI values of fuels bleeding.
Flocculation of fine particles in ceramic wastewater by using polymers
(Polish Mineral Engineering Society, 2014) Deniz, Vedat; Umucu, Yakup
The 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.

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