Kenan Çinku | Istanbul University (original) (raw)

Papers by Kenan Çinku

Nowadays, dry beneficiation technologies with an air dense medium fluidized bed come into promine... 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 from Soma (Imbat) region using a semi pilot scale Allair jig unit. The experimental studies were carried out with two coal size fractions of -15+4 and -4+1 mm by applying rougher and scavenging stages. After the optimization of each parameter, the results for the rougher stages indicated that clean coal products could be obtained with 11.80% and 16.74% ash contents for -15+4 mm and -4+1 mm size ranges, respectively. In addition, discardable tailings with 65.44% and 60.95 % ash contents could be obtained as the result for the scavenging stages. Finally, the combination of these results for -15+1 mm size exhibited that 59.80% of the feed material with 37.70% ash content can be upgraded to clean coal products with low ash content as 19.80% while the remaining part was discarded as tailings with 68.60% ash content. These values suggested that optimizing the operational parameters of unit brings better results which are applicable in industrial application of dry processes compared to wet processes.

Dry processing methods are well known to be sensitive to the moisture content of the processed ma... more 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 flow of feed material. In this study, the effect of total/surface moisture
on separation of lignitic coals was investigated by using Allair stratification jig with the aim of finding possible critical surface moisture content for optimum separation. Coal samples in the size of -13 + 4 and -4mm were processed at different particle
total=surface moisture levels to recover as clean coal concentrate as possible along with obtaining tailings with minimum levels of combustibles. It is envisaged that a
critical surface moisture on both classification (effective screening) and separation is available around 5.5% surface moisture (corresponding to 15% total moisture) for -13+4mm whereas effective separation is not possible for the +4mm size range even at minor changes in surface moisture of particles.

Montmorillonite is an important clay mineral due to its cation exchange capacity and technologica... more Montmorillonite is an important clay mineral due to its cation exchange capacity and technological properties such as swelling and gelling index etc. and, has been widely used in many scientific applications like organoclay. Meanwhile, adsorption themed studies with montmorillonite which depend on ion exchange processes by means of a variety of organic compounds like ammonium and phosphonium salts which are becoming very popular because of their usages in organoclay and polymer nanocomposites due to their higher thermal strengths. In this purpose, different types of phosphonium salts, namely Hexadecyl Triphenyl Phosphonium Bromide (HTPB), Hexadecyl Tributyl Phosphonium Bromide (HTBPB), and Tetraphenyl Phosphonium Bromide (TPB), were used to investigate the effect of these surfactants on the adsorption behavior of Na-montmorillonite. The last one was composed only of one aromatic head without an organic chain (TPB), whereas the others are in an organic chain with three branches (HTBPB) and an organic chain including one aromatic head (HTPB). The adsorption properties of these surfactants on the sample were also supported with the surface characterization tests, the zeta potential, surface tension, and flocculation measurement. The results clearly indicated that the adsorption behavior of these surfactants depend on their structure.

Applied Clay Science, 2010

Effect of calcined magnesite on rheology of bentonite suspensions: magnesia-bentonite interaction, 2014

In this study, the effect of calcination temperature and time on the structure of calcinated magn... more 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 explain the mechanism of viscosity increase in bentonite suspension upon addition of the calcinated products. FTIR, SEM, BET analyses and rheological data were used to determine the transition degree of MgCO3 to MgO, and evaluate the structure of MgO and bentonite suspensions. The results from this study showed that specific surface area (SSA) and mean pore diameter (MPD) values for the calcinated products were directly affected by the calcination temperature and time. According to the ignition loss and transition ratio from MgCO3 to MgO of calcinated samples, it was found that the calcination was completed above 800oC. In order to obtain a bentonite suspension with higher viscosity, the sufficient amount of MgO particles and interaction of these with bentonites particles were found necessary even if median pH and total dissolved ions values were stable. Based on these results, the formation of gelation and heterocoagulation between magnesite and bentonite particles were found to responsible for these.
Keywords: MgCO3, MgO, activation, bentonite, interaction, viscosity

International Journal of Mineral Processing, 2010

Upgrading of bentonites in sodium or mixed forms through wet separation methods is considered bec... more 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 subjected to a series of multistage hydrocyclone testing to evaluate the separation
efficiencies related to the hydrocyclone parameters such as vortex and apex diameters and feed pressures. In
each hydrocyclone test, the run of mine bentonite was split into different fractions of various qualities. The
separation efficiencies and the corresponding products were examined and characterized based on some
technological properties such as cation exchange capacity, viscosity, swelling ability along with particle sizes,
and chemical and mineralogical analyses. It is shown that for clay minerals such as smectites and also
bentonite minerals, cation exchange capacity is the best method for assaying the concentration products and
for evaluating the metallurgical balance though other characteristic properties such as chemical analysis,
swelling, gelling and viscosity could be used as complementary
Keywords: Na-Bentonite, Upgrading, Hydrocyclone, Beneficiation,
Smectite

INVESTIGATION OF ADSORPTION BEHAVIOR OF PHOSPHONIUM SALTS ONTO NA-MONTMORILLONITE, 2014

Applied Clay Science, 2010

Effect of calcined magnesite on rheology of bentonite suspensions: magnesia-bentonite interaction, 2014

International Journal of Mineral Processing, 2010

INVESTIGATION OF ADSORPTION BEHAVIOR OF PHOSPHONIUM SALTS ONTO NA-MONTMORILLONITE, 2014