Acid-Washing Behavior of TiB₂/MgAl₂O₄/MgO Composite Powders

Abstract:

Using TiO₂B₂O₃ powders as oxidizer,AlMg powders as reducer,the TiB₂ multiphase ceramic are preparated with SHS, and analysed with SEM and XRD.The effect of HCl, H₃PO₄ to pickling of TiB₂-based multiphase ceramics is explored by SEM and XRD analysis. Research suggests that: the main ingredients of TiB₂-based multiphase ceramics is TiB₂, MgO and MgAl₂O₄ three phases, few of reaction residual objects and impurities also exists; the multiphase ceramics is forming by many of hexagonal crystal type products and small particles reunion, hexagonal crystal type product is TiB₂, small particles may be MgO, MgAl₂O₄ and other impurities product; MgO can be effectively washed by HCl and H₃PO₄ , but TiB₂ and MgAl₂O₄ invalid. At room temperature, 30% HCl pickling has the best effect, the concentration of TiB₂(ω) is up to 59.3%; the higher of the concentration, the better of acid-effect; In the pickling process, as the temperature rises, the concentration of TiB₂ grows, but the temperature should not be too high. When temperature reach 75 °C, HCl volatilizes too quickly and inefficiently. At room temperature, 20% H₃PO₄ has the best pickling effect, the concentration of TiB₂(ω) is up to 52.6%, but the best pickling effect is not well with concentration increasing; as the temperature increasing, purity of TiB₂ is also increased; At 70°C, the concentration of TiB₂(ω) after H₃PO₄ pickling is up to 61.9%, refine effect is good.

• Periodical: Key Engineering Materials (Volumes 602-603)
• Pages: 101-104
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.602-603.101
• Online since: March 2014
• Authors: Ming Yuan Wang, Fang Zhao, Jun Shou Li, Su Li, Xiao Juan Wu
• Keywords: Ceramic Material, Chemical Purification, Combustion Synthesis, TiB₂

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