Production of titanium diboride

Download
2007
Bilgi, Eda
Titanium diboride was produced both by volume combustion synthesis (VCS) and by mechanochemical synthesis through the reaction of TiO2, B2O3 and metallic Mg. Reaction products were expected to be composed of TiB2 and MgO. However, side products such as Mg2TiO4, Mg3B2O6, MgB2 and TiN were also present in the products obtained by volume combustion synthesis. Formation of TiN could be prevented by conducting the volume combustion synthesis under argon atmosphere. Mg2TiO4 did not form when 40% excess Mg was used. Wet ball milling of the products before leaching was found to be effective in removal of Mg3B2O6 during leaching in 1M HCl. When stoichiometric starting mixtures were used, all of the side products could be removed after wet ball milling in ethanol and leaching in 5 M HCl. Thus, pure TiB2 was obtained with a molar yield of 30%. Pure TiB2 could also be obtained at a molar yield of 45.6% by hot leaching of VCS products at 75oC in 5 M HCl, omitting the wet ball milling step. By mechanochemical processing, products containing only TiB2 and MgO were obtained after 15 hours of ball milling. Leaching in 0.5 M HCl for 3 minutes was found to be sufficient for elimination of MgO. Molar yield of TiB2 was 89.6%, much higher than that of TiB2 produced by volume combustion synthesis. According to scanning electron microscope analyses, produced TiB2 had average particle size of 0.27±0.08 μm.

Suggestions

Synthesis of boron and zirconium co-doped titanium dioxide nanopowders by the sol-gel technique /
Ağartan, Lütfi; Öztürk, Abdullah; Park, Jongee; Department of Metallurgical and Materials Engineering (2014)
Effects of water/Ti precursor molar ratio (R ratio) and calcination regime on the photocatalytic properties of undoped, boron (B) doped, zirconium (Zr) doped, and B and Zr co-doped TiO2 powders synthesized by sol-gel process were researched. Undoped powders were synthesized for R ratio of 1, 3, 5, 10, 30, and 50 while doped and co-doped powders were synthesized for R ratio of 50. Undoped powders were calcined at 300, 400, and 500oC for 1, 2, and 3 h while doped and co-doped powders were calcined at 300 and ...
Production of lactic acid esters by reactive distillation
Yalçın, Özgen; Karakaş, Gürkan; Hamamcı, Haluk; Department of Chemical Engineering (2011)
The esterification of lactic acid with ethanol over Lewatit S 100, strong cation ion exchange resin catalyst, was studied in counter current vapor-liquid contactor type differential reactor by feeding ethanol and lactic acid solution as vapor and liquid phases, respectively. The ethanol vapor phase was diluted by dry air and the water removal was achieved by the mass transfer of water from liquid to vapor phase. Effect of ethanol to lactic acid feed molar ratio and vapor flow rate on fractional conversion a...
Formation of zirconium diboride and other metal borides by volume combustion synthesis and mechanochemical process
Akgün, Barış; Sevinç, Naci; Department of Metallurgical and Materials Engineering (2008)
The aim of this study was to produce zirconium diboride (ZrB2) and other metal borides such as lanthanum hexaboride (LaB6) and cerium hexaboride (CeB6) by magnesiothermic reduction (reaction of metal oxide, boron oxide and magnesium) using volume combustion synthesis (VCS) and mechanochemical process (MCP). Production of ZrB2 by VCS in air occurred with the formation of side products, Zr2ON2 and Mg3B2O6 in addition to MgO. Formation of Zr2ON2 was prevented by conducting VCS experiments under argon atmospher...
Synthesis, characterization and investigation of thermoluinescence properties of strontium pyrophosphate doped with metals
İlkay, Levent Sait; Özbayoğlu, Gülhan; Department of Mining Engineering (2009)
Strontium pyrophosphate is a promising phosphate that is used widely in the industry as a result of its luminescent, fluorescent, dielectric, semi-conductor, catalyst, magnetic and ion exchange properties. Thermoluminescent dosimetry (TLD) is one of such areas. Recent researches in METU on thermoluminescence property of strontium pyrophosphate showed that strontium pyrophosphate could give enough intensity for radiation dosimetry when doped with oxides of some rare-earth elements. In this study strontium py...
Photocatalytic properties of silver loaded titanium dioxide powders produced by mechanical ball milling
Aysin, Başak; Öztürk, Abdullah; Park, Jongee; Department of Metallurgical and Materials Engineering (2012)
Silver (Ag) was loaded to three different kinds (P-25, NT-22, and TiO(OH)2) of titanium dioxide (TiO2) powders through adding three different quantities (4.6, 9.2, and 13.8 ml) of silver nitrate (AgNO3) solution by mechanical ball milling process. X-Ray diffraction analysis suggested that Ag was loaded on the TiO2 powders in the form of silver oxide (AgO). SEM, particle size, and BET surface area analyses revealed that TiO2 particles agglomerated after ball milling, resulting in the decrease of specific sur...
Citation Formats
E. Bilgi, “Production of titanium diboride,” M.S. - Master of Science, Middle East Technical University, 2007.