Production of granular boron oxide by calcination of ammonium tetraborate tetrahydrate

Halil Demir, Ömer Şahin*, Mehmet Sait Izgi, Hasan Firatoglu

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

14 Citations (Scopus)


In this paper, the thermal calcinations of ammonium tetraborate tetrahydrate (ATT) to boron oxide investigated in fluidized bed calcinatory. Single step calcinations of ATT in pure state gives a puffed product with very low bulk density and the calcination is incomplete since ATT particles completely agglomerate at temperature higher than 350 °C. Effect of the temperature on the bulk density and particle size distribution product obtained at the end of single step is given and compared with theoretical calculation. In order to restrict agglomeration at temperature higher than 300 °C, the surface of ATT has been covered with a material with a higher melting point than boric oxide. In order to obtain this high melting cover, a mixture of ammonium tetraborate tetrahydrate and Ca(OH)2 has been calcined in fluidized bed calcinatory. During this calcinations process, quantities such as the bulk density value, particle size distribution and B2O3 content of product have been determined as a function of temperature. It was found that the boron oxide can be obtained by calcinations of ATT particle covered with Ca(OH)2 in 90 min time intervals at a temperature range of 450 and 500 °C. As a result, puffed granular boron oxide of 99% purity with bulk density about 0.30 g cm-3 has been produced using single step calcination by this new method.

Original languageEnglish
Pages (from-to)1-6
Number of pages6
JournalThermochimica Acta
Issue number1
Publication statusPublished - 1 Jun 2006
Externally publishedYes


  • Ammonium tetraborate tetrahydrate
  • Boron oxide
  • Calcium hydroxide
  • Fluid bed calcinatory


Dive into the research topics of 'Production of granular boron oxide by calcination of ammonium tetraborate tetrahydrate'. Together they form a unique fingerprint.

Cite this