Browsing by Author "Keskinkilic, Ender"
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Conference Object Citation Count: 0CALCINATION BEHAVIOR OF SIVRIHISAR LATERITE ORES OF TURKEY(John Wiley & Sons, 2011) Keskinkılıç, Ender; Pournaderi, Saeid; Geveci, Ahmet; Topkaya, Yavuz A.; Metallurgical and Materials EngineeringThis study investigated calcination behavior of one of the Turkish laterite deposits, which was recently found in Sivrihisar region. Representative limonitic laterite samples (1.26% Ni) taken from Yunusemre Karasivritepe and Kucuksivritepe location were first subjected to drying. Removal of chemically bound water and other volatiles were then studied, in detail. In the calcination experiments, temperature and time were the main experimental variables. Thermal treatment was conducted at the specific temperatures in 250 degrees C - 800 degrees C range. The weight losses due to elimination of chemically bound water and other volatiles were reported to be approximately 10 per cent of the weight of the ore. For the particle size used in the current work, 700 degrees C and 40 minutes were determined to be the optimum calcination temperature and time, respectively.Review Citation Count: 38Nickel Laterite Smelting Processes and Some Examples of Recent Possible Modifications to the Conventional Route(Mdpi, 2019) Keskinkılıç, Ender; Metallurgical and Materials EngineeringThe treatment of laterites has been a research hotspot in extractive metallurgy over the past decades. Industrially, the pyrometallurgical treatment of laterites is mostly accomplished with a well-established method, namely, the rotary kiln-electric arc furnace (RKEF) process, which includes three main operations-calcination, prereduction, and smelting-followed by further refining for the removal of impurities from the raw ferro-nickel. As indicated in many studies of the RKEF process, the major downside of this method is its high energy consumption. Efforts have been made to lower this consumption. Furthermore, several new processes have been proposed. Among these, low-grade ferro-nickel production is regarded as the most widely and industrially used process after traditional RKEF operation. Although not widespread, other alternative processes of industrial scale have been generated since the start of the millennium. Recently, certain innovative processes have been tested either in the laboratory or at pilot-scale. In this paper, a literature review related to the smelting of laterites is made, and an emphasis on new processes and some examples of new developments in the RKEF process are presented.Conference Object Citation Count: 1PRODUCTION OF CRUDE FERRONICKEL FROM SIVRIHISAR LATERITE ORES OF TURKEY(John Wiley & Sons inc, 2013) Keskinkılıç, Ender; Pournaderi, Saeid; Geveci, Ahmet; Topkaya, Yavuz A.; Metallurgical and Materials EngineeringIn the current work, laboratory-scale smelting experiments were conducted using Sivrihisar laterites (1.26% Ni). The ore samples previously subjected to drying, calcination and prereduction stages were smelted in alumina crucibles in a horizontal tube furnace under argon atmosphere. For the smelting system used in the present work, 1550 degrees C and 40 minutes were determined to be the optimum smelting temperature and time, respectively. 25% excess coal addition in prereduction stage was reported to be crucial to obtain the desired Ni content in the final product. Colemanite in calcined form has long been known as a flux used in pyrometallurgical systems such as steelmaking and copper matte-smelting. To investigate the effects of calcined colemanite addition on the ferronickel metal-slag system, calcined colemanite of 2% and 4% of the total metal and slag weight was charged as a flux and smelted under the optimum conditions described above.Conference Object Citation Count: 0Pyrometallurgical Studies for Manganese Extraction Using Turkish Ore Reserves(Springer international Publishing Ag, 2017) Keskinkılıç, Ender; Metallurgical and Materials EngineeringPyrometallurgical studies conducted for Mn extraction using Turkish Mn-ore reserves were reviewed. Turkish Mn-ores are low-grade ones having similar to 30% Mn. The most important Mn ore reserves in Turkey are in the Denizli-Tavas region, where more than 2 million tons of proven reserves are reported. Mining rights to the Denizli-Tavas manganese belongs to Eregli Iron and Steel Works Co. (ERDEMIR). The ore is usually charged to the blast furnaces of ERDEMIR during hot metal production. So far, nearly 20 Master's thesis studies have been conducted for the analysis of manganese extraction in Turkey. In the scope of the present work, only pyrometallurgical and related activities (i.e. ore beneficiation, calcination, etc.) relevent to the treatment of a specific ore were examined.Conference Object Citation Count: 0Recent Studies on Hot Metal Desulfurization(Springer international Publishing Ag, 2022) Keskinkılıç, Ender; Metallurgical and Materials EngineeringHot metal desulfurization station is an indispensable part of a modern integrated iron and steelmaking company. In this plant, roughly speaking, at least ninety percent of sulfur in hot metal is eliminated before basic oxygen steelmaking. In the conventional process, stable sulfide-making additives of various kinds and forms are introduced to the hot metal present in torpedo cars or more commonly in ladles. Together with desulfurization reactions, a slag rich in sulfides is collected at the top, and it is then skimmed out. Other than hot metal treatment stage, further removal of sulfur may be accomplished in secondary steelmaking, depending primarily on suitability of metallurgical conditions in that specific vessel. In this literature work, recent experimental studies related to hot metal desulfurization are reviewed. More emphasis shall be on the works performed after the millennium and specifically in the last decade, including the ones offering new and novel methods.Article Citation Count: 2Recovery of Iron from Turkish and Iranian Red Muds(Springer, 2022) Keskinkılıç, Ender; Keskinkilic, Ender; Topkaya, Yavuz A.; Geveci, Ahmet; Metallurgical and Materials EngineeringTurkish and Iranian red mud samples of different composition and mineralogy were processed by solid-state reduction followed by wet magnetic separation and smelting, two commonly used pyrometallurgical methods for iron recovery. The application of these two methods on the same samples allowed them to be compared thoroughly and to be examined for versatility. The results showed that it was possible to recover more than 90% of iron using both methods. However, the concentrate obtained by the first method contained a significant amount of undesirable oxides. Thus, large proportions (similar to 30%) of valuable elements that are planned to be recovered by hydrometallurgical methods were removed together with the iron. The smelting method, on the other hand, made it possible to recover the iron with high efficiency and as a marketable purity Fe-C alloy. The metal obtained by smelting contained 96% iron, 2% carbon, and a small amount of impurities like Si, Ti, and Na.Conference Object Citation Count: 1Smelting Studies for Recovery of Iron from Red Mud(Springer international Publishing Ag, 2019) Keskinkılıç, Ender; Pournaderi, Saeid; Geveci, Ahmet; Topkaya, Yavuz A.; Metallurgical and Materials EngineeringRed mud can be regarded as a by-product of aluminium extraction process since it contains a significant amount of iron and some valuable elements. Therefore, the treatment of red mud has been a hot topic for some decades. The authors have recently started a laboratory-scale project dealing with stepwise recovery of valuable elements from red mud of Seydisehir Aluminum Plant, Turkey. The first step is related to recovery of iron and pyrometallurgical methods (smelting and solid-state reduction) will be performed. Nonferrous metals will then be selectively leached in the second step. In the extent of the present work, a literature review relevant to the smelting studies for recovery of iron from red mud was presented.Conference Object Citation Count: 2Solid-State Reduction Studies for Recovery of Iron from Red Mud(Springer international Publishing Ag, 2020) Keskinkılıç, Ender; Pournaderi, Saeid; Geveci, Ahmet; Topkaya, Yavuz A.; Metallurgical and Materials EngineeringRed mud or bauxite residue can be regarded as a by-product of aluminum extraction process since it contains a significant amount of iron and some valuable elements. Therefore, the treatment of red mud has been a hot topic for some decades. Last year, the authors started a laboratory-scale project dealing with stepwise recovery of valuable elements from red mud of Seydisehir Aluminum Plant, Turkey. The first step is related to the recovery of iron and pyrometallurgical methods (solid-state reduction and smelting) are currently being performed. Nonferrous metals will then be selectively leached in the second step. In TMS 2019, the authors outlined the literature related to the smelting studies for iron recovery from bauxite residue. In the extent of the present work, a literature review relevant to the solid-state reduction studies for recovery of iron from red mud was presented.Conference Object Citation Count: 0A Statistical Analysis of Process Abnormalities in Slab Casting(Springer international Publishing Ag, 2018) Keskinkılıç, Ender; Metallurgical and Materials EngineeringContinuous casting of slabs is conducted with two successive steel flows: first from ladle to tundish, then from tundish to mold. There are certain process abnormalities related to ladle, tundish and mold. For example, change of submerged entry nozzle (SEN) is the one encountered during steel flow from tundish to mold. Tundish exchange is the abnormality taking place due to replacement of processed tundish with the new one at rest. Another example is the flow of steel from ladle to tundish without a ladle shroud. In this study, a statistical analysis was conducted related to the process abnormalities in slab casters of a steel plant. Slab surface defects observed in slab yard was incorporated in this analysis.Conference Object Citation Count: 1A Study on Recovery of Iron from Red Mud by Solid State Reduction Followed by Magnetic Separation(Springer international Publishing Ag, 2020) Keskinkılıç, Ender; Keskinkilic, Ender; Varol, Mustafa; Topkaya, Yavuz A.; Geveci, Ahmet; Metallurgical and Materials EngineeringRed mud is a waste material of the Bayer process for alumina production from bauxite ore. Red mud is generally pumped to disposal in an artificial pond which is accompanied by great land occupation and environmental issues. Many researches in different fields have been carried out to evaluate the red mud. Of these, researches on recovering valuable metals from red mud are the most successful. In this study, recovery of iron, which is the most abundant metal in red mud, was investigated. A red mud sample with 34% Fe2O3 was used. Solid state carbothermic reduction followed by wet magnetic separation was performed to recover iron. Reduction was carried out at temperatures 1000-1200 degrees C. Reduced samples were ground and subjected to wet magnetic separation. The effect of reduction temperature and grinding time were investigated on the metallization of iron and the iron content of the final concentrate.Conference Object Citation Count: 0A STUDY ON THE CHARACTERIZATION OF NICKEL LATERITES OF CENTRAL ANATOLIA(John Wiley & Sons inc, 2016) Keskinkılıç, Ender; Pournaderi, Saeid; Geveci, Ahmet; Topkaya, Yavuz A.; Metallurgical and Materials EngineeringThere are mainly three commercial nickel laterites in Turkey: Gordes, Caldag and Sivrihisar. The first two appear in Western Anatolia. The third one, Sivrihisar (Yunusemre) laterites have been found in the first decade of the millennium, in the Central Anatolia region of Turkey. Since then, mining facilities have been continued in Yunusemre. Calcination, prereduction and smelting of Sivrihisar laterites have been extensively studied and published. In the current work, some results of the studies related to characterization of Sivrihisar laterites will be presented.