Phases formed during the thermal analysis of pyrite in air
Phases formed during the thermal analysis of pyrite in air
复制标题
DOI：
10.1007/bf01912973
复制
发表时间：
1982-12
期刊：
影响因子：
--
通讯作者：
F. Jorgensen;F. Moyle
中科院分区：
文献类型：
--
作者：
F. Jorgensen;F. Moyle
通过热分析和淬灭反应不同阶段形成的物相，研究了黄铁矿的氧化过程。采用光学显微镜、扫描电镜、能谱仪、X射线衍射仪和微探针等手段对产物进行了表征。发现的相基本上是那些假设热力学和压力平衡预测。预测结果是：（1）低于404 °C时，赤铁矿将直接在黄铁矿表面形成，而在较高温度下，磁铁矿将介入;（2）高于552 °C时，磁黄铁矿将成为稳定相;（3）硫酸亚铁和硫酸铁将分别在低于583 ° C和644 °C的温度下在外层形成。黄铁矿的着火温度与磁黄铁矿形成的起始温度相对应。在一些TG痕迹逮捕归因于硫酸盐的存在下，逮捕的存在或不存在取决于由样品在氧化过程中持续的温度上升。
The oxidation of pyrite was studied by thermal analysis and quenching of the phases formed at different stages of the reaction. The phases were characterized by optical microscopy, SEM, EDAX, XRD and microprobe analyses. The phases found were essentially those predicted assuming thermodynamic and pressure equilibria. The predictions were that (1) below 404 °C hematite would form directly on the pyrite surface whereas at higher temperatures magnetite would intervene, (2) pyrrhotite would become a stable phase above 552 °C, (3) ferrous and ferric sulphates would form in the outer layers at temperatures below 583 and 644 °C respectively. The ignition temperature of pyrite was found to correspond with the onset of pyrrhotite formation. An arrest in some of the TG traces was ascribed to the presence of sulphates, the presence or absence of the arrest depending upon the temperature rise sustained by the sample during oxidation.