High pressure synthesis of siderite (FeCO3) and its thermal property
Wen Liang, Lin Chen, Luying Wang, Yuan Yin, Zeming Li and Heping Li
In order to study the thermal property of siderite (FeCO3) further, high purity siderite sample was artificially synthesized by a simple solid reaction under high temperature and high pressure for the first time. The properties of the as-synthesized siderite were investigated by X-ray powder diffraction and Raman spectroscopy, respectively. To find out the siderite stability region of a Pressure-Temperature (P-T) phase diagram, a high pressure synthesis was performed in various conditions, and in this case the principle of siderite synthesized under high pressure was strictly interpreted. The size of micro-particles observed from Scanning Electron Microscope (SEM) image exceeds to 20 micrometers and the Fe content was quantified by Electron Probing analysis. As a typical and important Fe-bearing carbonate mineral, its thermal property is investigated by Thermogravimetric (TG) analysis and high temperature XRD refinement, and the thermal expansion coefficient along c-axis (αc=1.061×10-5), the thermal expansion coefficient along the a-axis (αa=3.097×10-6/℃) and the volume thermal expansion coefficient (αV=1.666×10-5/℃) was measured.
Keywords: siderite; high temperature and high pressure synthesis; thermal expansion coefficient