Browsing by Author "Keskinkilic, E."

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Citation - WoS: 17
Citation - Scopus: 17
Calcination Characteristics of Laterite Ores From the Central Region of Anatolia
(Southern African inst Mining Metallurgy, 2012) Keskinkilic, E.; Pournaderi, S.; Geveci, A.; Topkaya, Y. A.; Metallurgical and Materials Engineering; Metallurgical and Materials Engineering; 06. School Of Engineering; 01. Atılım University
Drying, calcination, prereduction, and smelting are the main steps in conventional crude ferronickel production. Industrially, these steps are conducted using the rotary kiln-electric arc furnace (RKEF) process. In this paper, calcination characteristics of Sivrihisar laterite ores from the Central Anatolia region are investigated. The extent of elimination of chemically bound water and other volatiles was studied by experiments conducted at various temperatures in the 250-800 degrees C range. Phase changes were examined using X-ray diffractometry. For the particle size used in the study, 300 degrees C was determined to be almost sufficient for complete transformation of goethite to haematite, and 700 degrees C was required for effective elimination of all volatiles in the ore.
Citation - WoS: 1
Citation - Scopus: 2
Laboratory-Scale Smelting of Limonitic Laterite Ore From Central Anatolia
(Southern African inst Mining Metallurgy, 2017) Pournaderi, S.; Keskinkilic, E.; Geveci, A.; Topkaya, Y. A.; Metallurgical and Materials Engineering; 06. School Of Engineering; 01. Atılım University
The feasibility of ferronickel production from a low-grade limonitic laterite ore was investigated. The ore was first calcined and then prereduced in the solid state. The reduced ore was then smelted to produce ferronickel. The effects of coal addition, smelting temperature, and retention time on the process were investigated. Chemical and physical losses in the slag were separately quantified. Coal addition was the main parameter that controlled the ferronickel grade and losses in the slag. The melting point of the slag was well below that of the ferronickel, which enhanced metal-slag separation and minimized physical losses in the slag. A microstructural study of an industrial slag revealed that Cr-rich particulates, which were suspended in the slag, were mainly responsible for the physical losses in the slag.
Liquid Processing of Silicon Steels Using the Converter-Ladle Furnace-Circulation Degasser Route
(Southern African inst Mining Metallurgy, 2019) Keskinkilic, E.; Metallurgical and Materials Engineering; 06. School Of Engineering; 01. Atılım University
Electrical steels are used in motors, power generators, and transformers for electrical applications owing to their superior magnetic properties. These properties are attributed to the presence of a significant amount of silicon in the steel composition. Silicon steels are mainly grouped into two categories: grain-oriented (GO) and non-grain-oriented (NGO). The Si content of silicon steels is generally between about 0.50% and 6.5%. Therefore, silicon steels are further classified as low-, medium-, and high-Si steels. In this paper, liquid steel processing practices for certain silicon steel grades are outlined by considering a steelmaking company that integrates a basic oxygen furnace (BOF), a ladle furnace (LF), and an RH-type degassing unit (RH). Possible problems are identified, suggestions are discussed, and conclusions are drawn on the basis of real plant data.
Citation - WoS: 4
Citation - Scopus: 5
NEW TRENDS IN BASIC OXYGEN FURNACE DEPHOSPHORIZATION
(Technical Faculty, Bor-serbia, 2020) Keskinkilic, E.; Metallurgical and Materials Engineering; 06. School Of Engineering; 01. Atılım University
Except for special grades of steel where it is used as an alloying element, phosphorus is regarded as an impurity that must be removed. Considering the conventional integrated iron and steelmaking, there are primarily two processes for phosphorus removal. The first is a hot metal dephosphorization (DeP) process that is applied to a blast furnace for hot metal before the steelmaking process. The second is the basic oxygen furnace steelmaking (BOS), a unique method primarily used for steelmaking, with the exception of stainless steels. Hot metal phosphorus content has a direct impact on BOS. An increase of phosphorus in hot metal is mainly related to the use of high P2O5 containing iron ores. In the current literature review, new trends of phosphorus removal in converter steelmaking are outlined. The double-slag practice was reported to be successful when hot metal P content was larger than 0.100%. It was indicated that the tapping temperature was critical for the production of low-phosphorus grades for which maximum allowable P content was 0.007% and that high tapping temperatures should be avoided. The tap-to-tap time for the double-slag process was slightly longer than the conventional converter steelmaking. It was further reported that the double-slag practice would be more economical than an establishment of a separate hot metal dephosphorization unit, if low-phosphorus grades did not have a significant share in the product mix of a steelmaking company. Endpoint phosphorus prediction was one of the important recent trends of converter steelmaking. A mixed injection of CO2-O-2 to a basic oxygen furnace was applied to enhance dephosphorization, and promising results were reported. Unfortunately, a successful process for recycling of BOS dephosphorization slag has not been reported yet.
Recent Studies on Use of Waste Plastics in Integrated Ironmaking
(Springer Science and Business Media Deutschland GmbH, 2025) Keskinkilic, E.; Metallurgical and Materials Engineering; 06. School Of Engineering; 01. Atılım University
Around 7% of CO2 emissions are originated from the steel production. Nearly, three-quarters of the steel produced annually are obtained from the integrated route (BF-BOF). It is known that use of coke in BF results in 1700 kg CO2 emission per ton of hot metal. In relation to zero CO2 emission target, many investigations have been conducted in steelmakingSteelmaking industry for many years. One of them in blast furnaceBlast furnace process can be regarded as replacing coke with certain alternatives. In this respect, substitution of coal and coke with biomassBiomass, use of coke oven gas (COG), use of pure H2 gas, and use of waste plasticsWaste plastics are some examples to the efforts to reduce CO2 emissions. In this paper, the studies aiming to substitute coke with waste plasticsWaste plastics are reviewed. © The Minerals, Metals & Materials Society 2025.
Citation - WoS: 9
Citation - Scopus: 11
Reducibility of Nickeliferous Limonitic Laterite Ore From Central Anatolia
(Taylor & Francis Ltd, 2014) Pournaderi, S.; Keskinkilic, E.; Geveci, A.; Topkaya, Y. A.; Metallurgical and Materials Engineering; 06. School Of Engineering; 01. Atılım University
Limonitic nickel laterite from Sivrihisar reserve in Turkey was reduced at 700-1100 degrees C by the addition of 5.74, 8.61 and 11.48 wt-% coal under an argon atmosphere. The run-of-mine ore and the reduced samples were studied using X-ray diffraction. The metallisation of Fe was found to be limited up to 900 degrees C, but increased rapidly at higher temperatures. The metallisation of Ni and Co increased when the temperature was increased from 700 to 800 degrees C, almost levelled off up to 900 degrees C and then increased up to 1100 degrees C. The results also showed that increased coal additions did not affect Fe metallisation up to 900 degrees C. At 1000 degrees C the metallisation of Fe became slightly better, but its effect was more pronounced at 1100 degrees C. The increased coal addition affected the nickel reduction equally at all temperatures, while it had no effect on the metallisation of Co.
Citation - WoS: 4
Citation - Scopus: 5
Reduction Behavior of Iron in the Red Mud
(Technical Faculty, Bor-serbia, 2021) Eray, S.; Keskinkilic, E.; Topkaya, Y. A.; Geveci, A.; Metallurgical and Materials Engineering; 06. School Of Engineering; 01. Atılım University
Red mud or bauxite residue contains significant quantities of industrial metals such as Fe, Al, and Ti, as well as rare earth elements such as Sc, Ce, and La. The authors performed a laboratory-scale project dealing with stepwise recovery of valuable elements from two bauxite residues, namely Iranian red mud (IRM) and Turkish red mud (TRM). The first stage involved the recovery of iron which was present in large quantities in red mud. Two different methods were investigated for this purpose: 1) solid state reduction followed by wet magnetic separation and 2) smelting. In the scope of this paper, some results of pyrometallurgical part of this project are presented. According to solid-state reduction experiments, it was found that more excess coal was needed for IRM (35%) than for TRM (15%) to maximize iron reduction. Temperature had significant effect on the reduction process and metallization increased from about 70% to about 95% when the temperature was raised from 1000 to 1200 degrees C. Metallization degree was reported to be slightly higher for IRM (96.2%) than for TRM (94.1%). The results demonstrated that a high degree of iron metallization can be achieved regardless of the chemical and mineralogical composition of the bauxite residue sample.
Citation - WoS: 5
Citation - Scopus: 7
Sulfide-Type Inclusion Morphologies of a Ca-Treated Hot-Rolled Wheel Steel
(South African inst Mining Metallurgy, 2011) Keskinkilic, E.; Metallurgical and Materials Engineering; Metallurgical and Materials Engineering; 06. School Of Engineering; 01. Atılım University
In this study, sulfide-type inclusion morphologies of a Ca-treated hot-rolled wheel steel, Grade-X, were investigated. The specimens taken from the hot-rolled products of Grade-X heats were studied. The size and distribution of elongated sulfide inclusions were examined for the heats of different S levels. Elongated sulfide inclusions were either not observed or rarely encountered when ladle analysis S content was below 50 ppm. The size and relative abundance of sulfide inclusions were reported to increase markedly when the S composition was greater than or equal to 70 ppm and the Ca/S ratio was less than 0.50. The effect of Ti addition (0.010-0.020% Ti) on sulfide-type inclusion morphologies was then investigated for heats having a sulfur content higher than 50 ppm. Addition of Ti was found to have a partial effect on decreasing the size of sulfide-type inclusions under real steelmaking conditions.
Citation - WoS: 2
Citation - Scopus: 2
Use of Colemanite in Ferronickel Smelting
(Technical Faculty, Bor-serbia, 2019) Keskinkilic, E.; Pournaderi, S.; Geveci, A.; Topkaya, Y. A.; Metallurgical and Materials Engineering; 06. School Of Engineering; 01. Atılım University
Use of colemanite in metal-slag systems aims primarily to decrease the viscosity of slag and, therefore, achieve better metal-slag separation. Enhanced metal-slag separation is helpful to decrease the number of suspended metal/alloy droplets in slag, i.e. the physical losses. In the literature, successful use of colemanite was reported both in steelmaking and copper matte smelting processes. Ferronickel smelting slags contain nickel in the range of 0.1-0.2% and correspondingly, metal-slag distribution ratio values of nickel are reported even above 200. On the contrary, nickel recoveries are hard to exceed 95%. This can be mostly attributed to the physical losses of nickel due to very high slag volume in ferronickel smelters; for 1 ton of ferronickel, 10-15 tonnes of slag are generated regardless of the type of the laterite, which contains significant quantity of ,gangue components. The authors thought that use of colemanite could be a solution to decrease physical losses. Therefore, the use of colemanite in ferronickel smelting was investigated in the present work. Laboratory-scale smelting experiments were conducted using calcined and prereduced laterites in a vertical tube furnace under different gas atmospheres. The amount of colemanite added was in the range of 0 - 2.5% of the total charge. The experiments were also performed using ferronickel and slag samples obtained from a ferronickel smelter.
Variations in Chemical Composition of Some Steels During Continuous Casting
(Springer, 2012) Keskinkilic, E.; Metallurgical and Materials Engineering; 06. School Of Engineering; 01. Atılım University
In this study, chemical composition variations of some steels during continuous casting were investigated in Eregli Iron and Steel Works Co. (ERDEMIR), Turkey. Final chemical analysis of a heat is determined in the continuous casting stage. Three steel specimens are regularly taken from the mould at certain meters of slab strand for each heat. The aim of this work was to evaluate the extent of changes in chemical analysis along the slab strand. Consequently, the leading aim of this study was to determine whether the number of specimens taken for each heat could be decreased without compromising quality control of the continuous casting. This was accomplished for some low-carbon, ultra-low carbon, and structural steels, which constitute the majority part of the ERDEMIR product range. The results revealed that the number of specimens could only be decreased for a limited number of steels and under certain circumstances.