Downloads: 39

Files in This Item:
File Description SizeFormat 
mfeku_40_1_16.pdf1.34 MBAdobe PDFView/Open
Title: Hydrothermal Synthesis of Braunite in the Systems MnOOH-SiO₂, Mn₃O₄-SiO₂, and MnO₂-SiO₂
Authors: HINO, Hidenobu
MINATO, Taneo
KUSAKABE, Yoshihiko
Issue Date: Jan-1978
Publisher: Faculty of Engineering, Kyoto University
Journal title: Memoirs of the Faculty of Engineering, Kyoto University
Volume: 40
Issue: 1
Start page: 16
End page: 29
Abstract: Braunite (MnMn₆SiO₁₂) was synthesized at low temperatures with pressures from 1 to 2500 bar in the systems manganite (γ-MnOOH)-SiO₂, hausmannite (Mn₃O₄)-SiO₂, and pyrolusite (β-MnO₂)-SiO₂. Braunite-pyrolusite assemblage was produced in the first system and braunite-pyroxmangite (MnSiO₃) assemblage in the second system. In the third system, only braunite was formed as solid phase. These reaction equations are as follows. 8MₙOOH+SiO₂=MnMn₆SiO₁₂+MnO₂+4H₂O 3Mn₃O₄+3SiO₂= MnMn₆SiO₁₂+2MnSiO₃ 7MnO₂+SiO₂= MnMn₆SiO₁₂+2O₂ These reaction temperatures, under 1000 bar H₂O total pressure, are 272℃, 459℃, and 521℃ (Po₂=l bar), respectively. P-T diagrams were constructed to show the stability field of braunite. A good correspondence was found between the braunite assemblage synthesized in our laboratory and those observed in bedded manganese ore deposits.
URI: http://hdl.handle.net/2433/281063
Appears in Collections:Vol.40 Part 1

Show full item record

Export to RefWorks


Export Format: 


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.