摘要
图水羟砷铁矾是目前发现的存在于酸矿废水中的唯一的亚砷硫酸盐含铁矿物,其化学式为Fe6(AsO3)4(SO4)(OH)4.4 H2O。图水羟砷铁矾对研究酸矿废水中砷地球化学以及冶金含砷废水处理都具有重要意义。本文通过恒温水浴反应器合成该矿物,首次采用红外光谱和拉曼光谱对其表征,结果表明:位于770 cm-1处的红外特征峰来自矿物中As—O伸缩振动;位于609、663、512、455和365 cm-1处的拉曼特征峰分别来自矿物中As—OH不对称伸缩振动、As—OH伸缩振动(υ3)、AsO33-不对称弯曲振动(υ4)(512和455 cm-1)和O—As—O弯曲振动;光电子能谱结果表明矿物中As为+3价,不存在更高氧化态。低pH值和高硫酸根有利于矿物获得较好晶形;矿物在pH>3出现不谐溶解,首次测定矿物溶度积常数(Ksp)为107.7,标准吉布斯反应自由能(ΔG0f)为-3 605 kJ/mol。
Tooeleite is a ferric arsenite sulfate mineral only found in acid mine drainage at present, and its chemi- cal formula is Fe6 （AsO3）4 （804）（OH）4·4 H2O. Few literatures have reported this mineral, and hence some im- portant spectroscopic and mineralogical data are lacking. The authors synthesized tooeleite using temperature- constant water batch reactor, and for the first time adopted infrared and Raman spectroscopy techniques to char- acterize it. The result show that： the characteristic peak at FTIR of 770 cm-1 is attributed to stretch vibration of As--O; the characteristic peaks at Raman of 663, 609, 512, 455 and 365 cm-1 are attributed to the stretch vibration of As--OH （u3）, asymmetric stretch vibration （us）, asymmetric bending vibration （u4） of AsO3^3- and bending vibration of O---As--O; the incongruent dissolution occurs when pH of solution is higher than 3. The batch experiment determined for the first time the solubility product （Ksp） and the standard Gibbs free energy of the reaction, which are 107.7 and - 3 605 kJ/mol, respectively.
出处
《岩石矿物学杂志》
CAS
CSCD
北大核心
2012年第6期901-906,共6页
Acta Petrologica et Mineralogica
基金
国家自然科学基金资助项目(41002128)
科技部第六批"中国-南非联合研究计划"资助项目(2012DFG71060)
