碳钠铝石的X射线衍射及拉曼光谱特征

X-ray Diffraction and Raman Spectroscopy of Dawsonite

碳钠铝石既是CO2运移、聚集或逸散的"示踪矿物",也是CO2地下贮存的固碳矿物,其研究对于解决温室气体地下贮存具有重要意义。本文以砂岩裂缝中发现的碳钠铝石矿物单晶为研究对象,结合国外已有测试数据,进行碳钠铝石的X射线衍射及拉曼光谱研究。结果显示:①碳钠铝石X射线衍射主峰位的晶面间距分别为0.567,0.2784,0.2601,0.1988,0.1728,0.338和0.2151nm,对应的2θ角位于15.50°,26.50°和32.00°附近;②碳钠铝石发育6个拉曼主峰位,190cm-1和260cm-1的拉曼谱峰由ν(O-Al-O)弯曲振动形成,588cm-1的拉曼谱峰由ν(O-Al)伸缩振动形成,1090cm-1和1507cm-1的拉曼谱峰由ν(CO2-3)的伸缩振动形成,3280cm-1的拉曼谱峰由ν(OH-)伸缩振动形成。

Dawsonite is a tracer mineral for the migration, accumulation, and leakage of mantle magmatic CO2, and is also useful as a carbon-fixation mineral for CO2 sequestration purposes. Study of dawsonite is thus beneficial to geological storage of green house gases. In this work, we have characterized dawsonite single crystals found in the crack of sandstone in south Songliao basin using X-ray diffraction and Raman spectroscopy. Our results showed three main X-ray diffraction peaks with 20 and corresponding interplanar spacings of 15.50° （0. 567 nm）, 26.50° （0. 338 nm）, and 32.00° （0. 278 nm）, respectively. Six main Raman spectroscopy peaks were found for dawsonite, with peaks at 190 cm1 and 260 cm-1 assigned to v（O-A1-O） bending vibrations, 588 cm-1 assigned to v（O-A1） stretching vibration, 1090 cm-1 and 1507 cm 1 assigned to v（CO） stretching vibrations, and 3280 cm J assigned to v（OH ） stretching vibration, respectively.