热处理电气石的物相转变

STRUCTURE CHANGE OF DRAVITE-SCHORL AFTER HEAT TREATMENT

通过差热分析 (DTA)、热处理和X射线衍射分析 (XRD)等手段 ,研究我国西北某地区产的黑色电气石在热处理过程中的相转变过程 ,实验发现 85 0℃热处理 2h,电气石晶体结构的 [Si6O18]复三方环和 [BO3 ]三角结构已开始破坏 ,并出现新的物相———莫来石 (Al2 .3 5Si0 .64O4.82 ) ,铝硼氧化物 (Al5BO9)和赤铁矿 (Fe2 O3 ) ;890℃时 ,电气石分解形成的莫来石 (Al2 .3 5Si0 .64O4.82 )和赤铁矿 (Fe2 O3 )量增加 ,并有新物相 (Al2 O3 ) 9.97(B2 O3 ) 1.99形成 ;1 0 1 0℃时 ,莫来石合成体系的Si、Al和O的原子个数比发生了变化 (Al4.868Si1.13 2 O9.566) ,出现矽线石 (Al2 SiO5)、镁橄榄石(Mg2 SiO4)、顽辉石 (Mg(SiO) 3 )和镁铝硅硼酸盐 (Mg2 Al4Si4B4O3 7)等新物相。

The process of structure change of schorl from Shanxi was studied by differential thermal analysis (DTA), heat treatment and X ray diffraction (XRD). It was found that the hexagonal ring of Si tetrahedra [Si 6O 18 ] and the structure of triangles began to be destroyed at 850 ℃ for 2 hours to form new minerals--mullite (Al 2.35 Si 0.64 O 4.82 ), aluminum boron oxide (Al 5BO 9) and hematite (Fe 2O 3). At 890 ℃ for 2 hours, the schorl also changed into mullite (synthetic) (Al 2.35 Si 0.64 O 4.82 ) and aluminum borate [(Al 2O 3) 9. 97 (B 2O 3) 1.99 ], and the intensity of XRD of hematite increased. At 1010 ℃ for 2 hours, the numbers of Al, Si, and O atoms of mullite (synthetic) (Al 4.868 Si 1.132 O 9.566 ) changed, and Werdingite Syn (Mg 2Al 14 Si 4B 4O 37 ), sillimanite (Al 2SiO 5) and magnesium silicate [Mg 2SiO 4, Mg(SiO 3)] appeared.