Feridun Boylu

Istanbul Technical University · Department of Mineral Processing Engineering

In recent years, most of the studies have been adapted to determine the optimum conditions for the flotation of very fine minerals. In this context, besides parameters such as particle size, morphology, and pH, the effects of frother type and its concentration present a very significant role in optimizing the flotation conditions. Therefore, the ef...

This work analyses the basic problems of the fine particles flotation and suggests new ways to overcome them. It is well accepted that the poor recovery of fine particles is due to the small collision rate between them and the bubbles due to the significant difference between their sizes. This common opinion is based on a theory, assuming in its fi...

The conventional flowsheet of coal washing plants includes sequential units where different coal size fractions are washed. Generally, coal washeries include dense medium vessels/drums and cylones for coarse and intermediate sizes as well as spirals and flotation units for fine/ultrafine fractions. Three product-dense medium cyclones (TPDMC) may re...

Clay minerals need to be dispersed with blungers before their utilization in the related industries due to their plastic properties, and size reduction is carried out in a wet medium. Clay minerals also contain impurities such as nonplastic materials in their structure. Mechanical dispersion parameters are important in the separation of clay group...

It is a common rule that the strength of the frother is assessed by either its dynamic foamability index (DFI) or its critical coalescence concentration (CCC). The smaller the value of CCC the stronger the frother is. This general rule (CCC rule) however is superficial although being well accepted. Yet, there are critical questions about the perfor...

Removal of impurities from quarzite to obtain for glass quality sand.

This paper studies the effect of the type and concentration of selected frothers, the gas flowrate, and the pore size of the porous frit on the bubble sizes (Sauter mean diameter, SMD) of bubbling flow produced in a micro-flotation cell, and the determination of bubble size distribution (BSD) in the presence of the frothers. The commercial frothers...

In this study, the critical coalescence concentrations (CCC) of selected commercial frother solutions, namely polypropylene glycols (PPG 200, 400, and 600), tri propylene glycol (BTPG), triethylene glycol (BTEG), dipropylene glycol (BDPG), and as a reference, methyl isobutyl carbinol (MIBC), were determined using a bubble column based on light abso...

This paper studies the effect of the type and concentration of selected frothers, the gas flowrate, and the pore size of the porous frit on the bubble sizes (Sauter mean diameter, SMD) of bubbling flow produced in a micro-flotation cell, and the determination of bubble size distribution (BSD) in the presence of the frothers. The commercial frothers...

It is a common rule that the strength of the frother is assessed by either its dynamic foamability index (DFI) or its critical coalescence concentration (CCC). The smaller the value of CCC the stronger the frother is. This general rule (CCC rule) however is superficial although being well accepted. Yet, there are critical questions about the perfor...

In this study, the critical coalescence concentrations (CCC) of selected commercial frother solutions, namely polypropylene glycols (PPG 200, 400, and 600), tri propylene glycol (BTPG), triethylene glycol (BTEG), dipropylene glycol (BDPG), and as a reference, methyl isobutyl carbinol (MIBC), were determined using a bubble column based on light abso...

Can the critical coalescence concentration (CCC) of the flotation frothers be predictable ? What is the relation between their molecular structure and their CCC values? A literature survey found specific correlations between the hydrophilic-lipophilic balances (HLB) and HLB/Mw (where Mw stands for the molecular mass) of homologue series of frothers...

Can the critical coalescence concentration (CCC) of the flotation frothers be predictable? What is the relation between their molecular structure and their CCC values? A literature survey found specific correlations between the hydrophilic-lipophilic balances (HLB) and HLB/Mw (where Mw stands for the molecular mass) of homologue series of frothers...

One of the new trends in coal processing to remove the inorganics from coal is to use of more simple and economic separation devices such as three products dense medium cyclone (TPDMC). TPDMC consists of combined Larcodem and dense medium cyclone allowing to the two-stage separation at different separation densities. Application of only one medium...

Coal quality is generally defined based on the ash contents. It is well known that the calorific value of coal is negatively affected by the increase on ash contents. However, the attitude of calorific value is not only dependent on ash content, it is also controlled by proximate and ultimate coal analysis components such as moisture, volatile matt...

Fine and ultrafine coal (−200 µm) enrichment and its further dewatering processes are more difficult than that of coarser sizes. Utilization of this size fraction, however, is inevitable due to economic and environmental enforcements. Chemical reagents are widely used in fine coal dewatering to achieve lower cake moistures. Surfactants of the same...

The current energy policies which reveal the indispensability of "primary sources" in energy production will not change in the near future. In the international arena "New Politics Scenario", emphasizes the role of national energy resources in other words the priority assessment of Turkey's indigenous resources by the motto of "National Energy" and...

Airjigs employ air instead of water or heavy liquid as separating media thus separation is achieved by stratification through the fluidizing and pulsing (and/or vibrating) effects. In practice, although stratification is achieved successfully, proper discharge of the float and sinks (light and heavy minerals) materials can be accomplished. In addit...

Air entraining admixtures (AEA) are generally used to increase the workability and resistance to freezing and thawing in concrete. These admixtures generate air bubbles with diameters ranging from 10 μm to <1 mm, providing spaces for the expansion of ice, and therefore facilitate frost protection. In this study, performances of AEAs were investigat...

The Arsenic (As) content in Turkish colemanite ores varies in between 1050 and 3800 ppm. Arsenic minerals are found in the form of realgar and orpiment. Literature survey revealed that the removal of the entire As content from colemanite ore by calcination is not possible. In this context, colemanite ore from Eti Maden Emet Espey region was examine...

In Turkey, the average medium (magnetite) losses in coal processing plants are in the levels of 1000 g and 3500 g/ton for coarse and fine coal circuits. The poor water spraying and screening through drain and rinse (D&R) screen is one of the major sources of medium loss. Especially in dense medium cyclone (DMC) circuits, the bottom size of the DMC...

Since montmorillonite (Mt) and organomontmorillonite (O-Mt) are widely used in many different areas from ordinary to high technological applications, there are lots of studies about them in the literature. However, its unique characteristic and different interaction mechanism with additives make those studies continue in order to explain much more...

Nowadays, dry beneficiation technologies with an air dense medium fluidized bed come into prominence in the field of coal preparation. In this study, the optimum conditions for different operational parameters such as discharge stargate rate, pulsation frequency, and superficial air velocity were investigated on separation of semi bituminous coal f...

Dry processing methods are well known to be sensitive to the moisture content of the processed material. It is well known that, cohesive forces among the particles originating from the surface moisture hinder the individual movement or appropriate stratification of particles during separation. Furthermore, high surface moisture also hampers the flo...

Dacitic andesitic calc-alkaline lavas and their pyroclastic rocks of Upper Cretaceous age are widespread in the Ordu area, eastern Black Sea Coast of Turkey. Ca-bentonite and Ca/Na-bentonite deposits with significant economic potential formed in the broader region. The mineralogy and geochemistry of these deposits were studied by X-ray diffraction...

ZET: Bu çalışmada Soma bölgesi İmbat, ve Eynez (açık ocak) ocaklarında üretilmekte olan kömürler üzerinde, pilot ölçekli Allair Jigi kullanılarak kuru zenginleştirme çalışmaları gerçekleştirilmiştir. İmbat (beslenen kül içeriği: % 46,54) ve Eynez (beslenen kül içeriği: % 40,94) kömürleri üzerinde gerçekleştirilen iki kademeli kuru zenginleştirme iş...

In this study, fine coal from the Tunçbilek Region (Turkey) was subjected to autogenous medium washing tests. The autogenous medium was formed in the presence of clayey minerals with the increased solids concentration of the feed slurry. The clayey minerals also acted as tracer to investigate the conditions of free settling conditions where the par...

In this study, the effect of calcination temperature and time on the structure of calcinated magnesite was investigated. In addition, the effect of calcinated magnesite on rheology when added into bentonite suspension was also examined. Electrokinetic, rheological and stabilization studies including coagulation and gelation tests were performed to...

In this study, the free and hindered settling conditions for coal-shale-clay separation through a Falcon concentrator were determined experimentally using response surface methodology. The model parameters consisted of the separation efficiency and ash content of the concentrate and tailings. Based on the model with the highest response, free settl...

Sustainability of product quality is important for the consistency of commercial bentonites. Nowadays, this issue is receiving more attention, especially for treated products such as activated bentonites. Even minor changes of process conditions might result in major problems or improvements in final quality in applications such as foundry and dril...

Dry processing of coals has been getting more attention nowadays due to the global water shortage and high costs of dewatering and thermal drying. Producers, especially from the coal beneficiation plants were suffering the environmental forces on tailing dams. Most of the coal suppliers producing coals for coal fired power plants have been giving a...

In this study, the production of ultrapure Na-bentonite by centrifuge based techniques for organo and nano composite bentonite industry was investigated. Various parameters including centrifuging time, solids content and g force were studied to determine the set points (cut size) for theoretical CEC (cation exchange capacity) and recovery limits. T...

Cellulosic insulators typically consist of various additives including cellulose, flame retardant minerals and different binders. Such composite materials can be produced at various combinations of mineral additives, i.e., perlite, pumice, and vermiculite. In this study, 70% cellulosic shredded waste newspaper were mixed with boron additives to pre...

We prepared biocomposite gel dispersions involving sodium alginate (Na-Alg) and calcium bentonite (Ca-B) with various solid concentrations and characterized their rheological, electrokinetic, and morphological properties. The flow properties, such as the apparent and plastic viscosities, shear stress, and yield value point, changed with increasing...

Mineral additives in paint constitute anywhere from 20 to 50 % of the paint formulation. Particularly, water based paint formulations utilize maximum quantities of mineral additives particularly those titanium dioxide (rutile and anatase), calcite, mica, clay minerals (thickeners), quartz, feldspar, barite and pigments. In the present paper, the ef...

Following soda activation, the bentonite properties fluctuate and change more or less with time depending on the soda addition. Since these changes on activated bentonite properties are reflected in the further use of these products, controlling methods should be developed to optimize the product quality. In this study, optimization was achieved us...

Cellulose. has widespread industrial use but js extremely flammable in many of its forms. Borates, mainly boric-acid, are added to celluloric-ui.ri;F6 h;il-lju*. retardancy, enabling !!.-to meet safety standards and regulations. In this stud',-U'o*t", u.ra ftllet minenls are added to waste newspapff foilowed 6y watir iaait;o, ut"i Aiiii una pressed...

Bentonites have been utilized in a variety of industries. Among these applications, drilling mud has the largest share of 40 %. Sodium bentonites exhibit high cation "*rhung. capacitieJand thixotropy whereas the other types usuaily. need activation by mostly soda. Ii some applications, MgO is also used for higher viscosity and thixotropy despite de...

A comparative study is presented to delineate the effect of talc as an extender on paint quality and .performance. In this study, 1F"" commercial talc samples of different Pllsical an{ chemical properties were introduced into the paint recipes with varying amounts of 5, l0 and 12.5 wt oA talc, resulting.in nine different paint recipes. Standard pai...

Upgrading of bentonites in sodium or mixed forms through wet separation methods is considered because such low solid suspensions require filtration followed by drying. These wet separation methods turn into effective and compatible processes for high selling prices such as water and solvent based bentonites. In this study, Na-bentonites were subjec...

In this study, the collector, also called as the bridging oil, used in both oil agglomeration and flotation is introduced to test in the form of emulsion. Kerosene, Fuel oil and Diesel oil were used for both flotation and oil agglomeration as bridging oil or collector. In flotation experiments, MIBC, DTAB and n-Decanol were also used as frother, an...

In this study, Ca-bentonite was subjected to a series of systematic hydrocyclone tests with the aim of developing separation procedures and in turn achieving optimum recoveries. In hydrocyclone tests, vortex and apex diameters and also feed pressures were investigated. In each hydrocyclone set, vortex diameter was kept constant while the other two...

Nickel sulphide ore subjected to this investigation was taken from the Marmara district of Turkey, where widespread chromite mineralization can be observed. Some amounts of magnetite and chromite exist in the ore together with sulphide and oxide type nickel minerals. The ore sample contains 1.32% Ni, 10.79% SiO2, 78.39% Fe2O3, 1.3 g/t Ag, and 1.0 g...

ZET Bentonit cevherinin, özellikle sodyum ve ara tip bentonitlerin hidrosiklon ile zenginleştirilmesi yaş bir yöntem olduğundan zenginleştirme sonrasında kurutma işlemi ekonomik olmayan bir yöntem olarak ifade edilmektedir. Oysaki özellikle yüksek fiyatlı su ve solvent bazlı bentonit üretimi, yaş işlemlerle bu tip bentonitlerin smektit oranlarının...

The entrainment of hydrophilic gangue particles in flotation is related to the amount of water reporting to the froth. It is well established that the amount of water reported to the froth is controlled by frother concentration. As it is shown in this paper, in the flotation systems in which emulsified oily collector is also used (e.g. coal flotati...

One of the main objectives in coal-water slurries (CWS) technology is to keep the slurry stable without coal sedimentation after certain storage times. Therefore, some chemicals and stabilizers are used to control the CWS stability. Stabilizers create a network system among the coal particles and make them stable. The major control factors for the...

In this study, the grinding conditions in the preparation of coal-water slurries were improved by the use of the dispersing agents PSS and NSF and viscosity values much less than 1000 mPa were obtained. Under the optimum concentrations (0.3% and 0.7% PSS to mass of coal) attainable in the presence of PSS and NSF, it was observed that the conservati...

In the scope of this study, the combustion experiments were performed with CWSs prepared from Zonguldak bituminous coal, Soma semi bituminous coal and Istanbul - YenikÖy lignite coals in pilot type down fired coal combustor. The particle size and combustion ratio were kept as constant in the experiments. The coalification degree which play an impor...

Today 90% of electricity in the world is produced from fossil fuels such as coal, oil and naturel gas. Oil equivalent of fossil in the world is calculated to be 68% coal, 18% oil and 14% natural gas. According to these figures the lifetime of oil, natural gas and coal is 40, 60 and 220 years respectively. Coal water slurries (CWS) and coal oil mixt...

The effect of PSS (Sodium Polystyrene Sulphonate) and NSF (Naphthalene Sulphonate Formaldehyde Condensate) chemicals used to control the pulp rheology on the grindability of coals was studied. Zonguldak region bituminous coal and Istanbul region brown coal samples that high and low rank were used. Wet grinding tests with two coal samples were perfo...

In this study, atomization properties of coal-water slurries (CWS) prepared with Zonguldak bituminous coal, Soma sub-bituminous coal and Istanbul-Yeniköy brown coal were investigated. Ai: the atomization tests of coal-water slurries prepared using 0.3% PSS (Sodium Polystyrene Sulphonate) as dispersant and 0.01% CMC (Carboxymethyl Cellulose) as stab...

In this study, combustion experiments were carried out by using different rank coals from Turkey. The experiments, performed at a constant coal particle size and combustion ratio suggested that the coalification degree, which is very important parameter in preparation of coal-water mixtures, is not effectual on the combustion of coal-water slurries...

In this study, the effect of carboxymethyl cellulose (CMC) used as stabilizer in the preparation of coal-water slurries on the stability has been investigated. Experiments have been carried out on the coal samples which differ in rank. Besides two different Turkish Lignites (Soma and İstanbul) also a bituminous coal (Thermal Code No. 434) of Turkis...

This study covers the studies of CWS preparation and combustion properties on the Turkish lignite with low coal calorific (3675 Kcal/kg) value and high ash forming minerals (41 %) that may be regarded as coal wastes. The particle size, coal concentration, air/fuel ratio and atomizing air pressure effects on both slurry preparation and combustion pr...

Utilization of Turkish bituminous coals for the application of CWS (Coal-Water Slurry) technology is covered by this study. The factors related with slurry preparation and combustion, such as viscosity, stability, atomization and combustion properties of slurry were investigated on Turkish coal sample taken from Zonguldak-Armutçuk. The results of v...

The aim of this study was to understanding of the effect of coal particle size distributions on rheology of coal–water slurries (CWS). Experiments have been carried out on the coal samples that were different in rank. Besides two different Turkish lignites (Soma and Istanbul–Agacli), a bituminous coal from Siberia (Russia) has been used. In additio...

In this study, the effects of different chemicals that were used as dispersing agent and stabiliser on the stability and viscosity of coal–water slurries have been investigated. In the experiments, anionic type of chemicals—polyisoprene sulphonic acid soda (Dynaflow-K), a derivative of carboxylic acid (AC 1320) and naphthalenesulfonate–formaldehyde...

Studies on coal–water slurries (CWSs) have been conducted for many years to replace fuel oil. In this research project, the effect of coal properties on CWSs have been investigated using two Turkish coals of different ranks and a Siberian bituminous coal. Physical, chemical and surface properties of coal samples were determined. Furthermore, adsorp...

A new concept in carrier flotation has been developed where highly hydrophobic coarse carrier coal particles are coated by slime size, extremely hydrophilic (unfloatable) coal particles of low-rank and the resultant aggregate floated with frother alone. A systematic flotation study in a Denver cell as a function of carrier size, the ratio of carrie...

In order to remove sulfur and inorganic matter content of coal, high intensity magnetic separation tests were carried out, where % solids in the pulp, current intensity in ampere, feed rate and middling wash water were investigated. Under optimum conditions, a clean coal was obtained having 8.10% ash, 1.56% total sulfur, with a combustible recovery...

ÖZ Bu çal›flmada, kömürleflme derecesi birbirinden farkl› olan üç farkl› Türk kömüründen haz›rlanm›fl kar›fl›mlar üze- rinde yakma deneyleri gerçeklefltirilmifltir. Kömür tane boyutu ve yanma oran› sabit tutularak gerçeklefltirilen yak- ma deneyleri sonucunda, kar›fl›m haz›rlama aflamas›nda etkili olan kömürleflme derecesinin, kar›fl›mlar›n yak›lma...

In this study, atomization properties of coal-water slurries (CWS) prepared with Zonguldak bituminous coal, Soma sub-bituminous coal and Istanbul-Yeniköy brown coal were investigated. At the atomization tests of coal-water slurries prepared using 0.3% PSS (Sodium Polystyrene Sulphonate) as dispersant and 0.01% CMC (Carboxymethyl Cellulose) as stabi...

ZET Türkiye'de genellikle bir zenginleştirme işlemine sokulmaksızın doğrudan kullanım yoluyla ekonomiye kazandırılan bentonit, dünya çapında da genellikle kuru prosesler uygulanarak değerlendirilmekte, yaş yöntemler ise tercih edilmemektedir. Tipik bir bentonit, esas olarak montmorillonit ve %10–30 arasında değişen oranlarda karbonat, feldspat ve s...