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    Corrosion behaviours of MgO-C refractories: Incorporation of graphite or pyrolytic carbon black as a carbon source
    (ELSEVIER SCI LTD, 2018) Bahtli, Tuba; Hopa, Derya Yesim; Bostanci, Veysel Murat; Ulvan, Nesibe Sevde; Yasti, Serife Yalcin
    In this study, corrosion behaviours of MgO-C refractories produced by the incorporation of carbon and pyrolytic carbon black obtained from waste tire pyrolysis under either argon or oxygen atmospheres were investigated. Moreover, the effect of porosity on the corrosion resistance of those refractories was studied. The microstructures of corroded refractories were characterized by Scanning Electron Microscopy (SEM)/EDX. Experimental studies indicated that refractories produced by the use of pyrolytic carbon black as a carbon source had higher amount of porosity due to their lower packing density and lower corrosion resistance than those of ones produced by the incorporation of graphite.
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    Investigation of thermal shock behaviour of MgO-C refractories by incorporation of pyrolytic liquid as a binder
    (ELSEVIER SCIENCE SA, 2018) Bahtli, Tuba; Hopa, Derya Yesim; Bostanci, Veysel Murat; Yasti, Serife Yalcin
    Tire waste is a serious problem for environment, health, and safety due to growing in volumes of its production. Recycling and recovery of waste tire as a useful product has a real importance. In this study, pyrolytic liquid obtained by waste tire pyrolysis was incorporated into MgO-C refractory as a binder to investigate the effects of its utilization on the thermal shock resistance of MgO-C refractories. The physical properties such as open porosities, densities, and mechanical properties such as Cold Crushing Strength (CCS) and 3-Bending Strength were investigated before and after thermal shock test at 1000 degrees C. The microstructure and fracture surfaces were characterized by using the Scanning Electron Microscopy (SEM). Elemental analysis of those refractories were examined by the Energy Dispersive X-Ray (EDX) analysis. Experimental studies showed that refractories produced by the use of pyrolytic liquid as a binder could have less reduction in their strength values after the thermal shock test. (C) 2018 Elsevier B.V. All rights reserved.
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    Thermal conductivity of MgO-C refractory ceramics: Effects of pyrolytic liquid and pyrolytic carbon black obtained from waste tire
    (ELSEVIER SCI LTD, 2018) Bahtli, Tuba; Hopa, Derya Yesim; Bostanci, Veysel Murat; Yasti, Serife Yalcin
    In the present study, thermal conductivity and mechanical properties of MgO-C refractory ceramic bricks were investigated. Pyrolytic liquid and pyrolytic carbon black obtained from pyrolysis of waste tires were used as a resin and carbon source, respectively. The pyrolysis of the tires was conducted in a fixed bed reactor at the temperature of 500 degrees C with a 15 degrees C/min heating rate under nitrogen flow (0.5 It/min). Before using in MgO-C refractory ceramic blends, pyrolytic products were purified with the acidic extraction methods which resulted in 61 and 66 wt%. decreases in sulfur and ash contents in pyrolytic carbon, respectively. After this treatment of pyrolytic liquid, the sulfur content was reduced by 24 wt%. Eight different blends of MgO-C refractory ceramics consisting of different pyrolytic product contents were prepared, pressed, and tempered at 250 degrees C, and then characterized in terms of porosity, thermal conductivity, and density. The mechanical behavior of the samples was tested using a three-point bending test. Archimedes test was employed to determine the porosity and density. Surface properties of the bricks were analyzed by scanning electron microscopy (SEM). The obtained results were compared with a reference consisting of graphite and resin. The results revealed that mechanical and thermal properties of the developed bricks were highly sensitive to the porosity and the carbon source as well as the type of binder.