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Ankara, Turkey

Karabulut A.F.,Osmaniye Korkut Ata University | Guru M.,Gazi University | Boynuegri T.A.,Eti Mine Works | Aydin M.Y.,Gazi University
Journal of Electronic Materials

In this study, synthesis of Ca(BH4)2 has been carried out with a solid phase reaction in which synthetic colemanite has been used as a raw material. Three dimensional high energy spex collider was selected for this mechanochemical reaction. Calcium borohydride is one of the most valuable metal borohydrides. In order to produce calcium borohydride economically, anhydrous colemanite mineral has been used as reactant. Calcium borohydride has been directly manufactured from anhydrous colemanite in spex-type ball milling without the need for any intermediate product. Thus, the advantages of this method over wet chemical procedure (such as having no intermediate product, no azeotropic limitations and no need of regaining product from solution after production by using evaporation, crystallization and drying processes) have made it possible to achieve the desired economical gains. Parametric experiments were conducted to determine the best conditions for the highest yield of solid phase reaction in the spex-type ball milling. Best results have been determined by using areas of related peaks in spectra of Fourier transform infrared spectroscopy (FT-IR). In order to use peaks area for determining Ca(BH4)2 concentration, a calibration graph of FT-IR absorbance peak areas has been created by using samples with known different concentrations of commercial Ca(BH4)2. Optimum amounts of calcium hydride and synthesis reaction time were found to be 2.1 times the stoichiometric ratio and 2500 min, respectively. As a result of these optimizations, the maximum yield of the solid phase reaction carried out by the spex-type ball milling has been determined as 93%. © 2016 The Minerals, Metals & Materials Society Source

Bilen M.,Eti Mine Works | Guru M.,Gazi University | Cakanyildirim C.,Hitit University
Energy Conversion and Management

This study explains completely feasible route to synthesize NaBH 4 by means of mechano-chemical reaction, in which NaCl, B 2O3 and MgH2 were utilized. Optimum reaction conditions were investigated by different values of reactant ratio and duration to reach 95% NaBH4 purity. In addition, commercial NaBH4 was hydrolyzed with CoI2 supported on activated carbon (AC). Intermediate steps of the studies were traced by means of FT-IR, XRD, SEM and EDX analyses. Activation energy of the catalyst was searched at distinct reaction temperatures and found as 36 kJ/mol. Optimum working time for ball-milling reactor and reactant ratio (MgH2/NaCl) were obtained as 1000 min and 1.0, respectively. © 2013 Elsevier Ltd. All rights reserved. Source

Yilmaz O.,Eti Mine Works | Bilen M.,Eti Mine Works | Guru M.,Gazi University
International Journal of Hydrogen Energy

In this study, it is aimed that to reduce environmental effects of CO2 (as a greenhouse gas), to achieve absorption of CO2 in boron solutions and to yield a mixture product with boron compounds and the NaHCO3 which is raw material input especially in glass industry. In the laboratory scale experiments using autoclave, with different pressure, solid/liquid ratio, and different reaction times, absorption of CO2 in the boron solutions were examined and the Na-borate compounds containing NaHCO3 were produced. The characterization of the products was determined by XRD inspections and chemical analysis. In the studies, maximum 92.4% NaHCO3 bearing borate compounds was obtained. As a result of the purification of these products it was reached pure NaHCO3 by 99%. © 2015 Hydrogen Energy Publications, LLC. Source

Bilen M.,Eti Mine Works | Yilmaz O.,Eti Mine Works | Guru M.,Gazi University
International Journal of Hydrogen Energy

This study deals to synthesize LiBH4 by means of mechano-chemical reaction, in which LiBO2 and MgH2 were utilized. In order to obtain 90% LiBH4 purity, optimum reaction conditions were analyzed at different values of reactant ratio and duration. In addition, commercial LiBH4 was hydrolyzed with CoI2 supported on activated carbon (AC). In order to follow up the intermediate steps of the studies FT-IR, XRD analyses have been used. Activation energy of the dehyrdogeneration reaction was searched at different reaction temperatures and determined as 33.12kJ/mol. As an optimum operation time for ball-milling were recorded as 1000min and reactant ratio (MgH2/LiBO2) were found as 1.0. © 2015 Hydrogen Energy Publications, LLC. Source

Yilmaz O.,Eti Mine Works | Yalcinoglu Y.,Eti Mine Works | Bilen M.,Eti Mine Works | Uludag T.,Eti Mine Works | Senturk B.,Eti Mine Works
Journal of the Faculty of Engineering and Architecture of Gazi University

In this study, the calcined tincal produced in laboratory scale at ETİ Mine Works General Management, Technology Development Department previously, in the light of the data obtained from the laboratory, micronize calsined tincal production has been madein industrial size. For this purpose, an industrial scale pilot plant has been established at The Directorate of Kirka Boron Works. In this plant, calcined tincal is obtained by single-stage in the rotary calcination furnace. This process is called as "single step calcination - autogenous grinding-separation method (CGS)". In the mentioned process, by applying heat treatment; products were manufactured with higher B 2O3 grade, lower H2O content and lower impurities. Since its size is micron level, product was named "Micronize Calcined Tincal" and the production yield was about 90% on the basis of B2O3. The calcined tincal obtained by this method, is a new commercial product as well as an alternative input for the production of borax penta hydrate, was patented. Source

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