摘要
通过XRD和IR对湖南湘潭锰矿中含锰氧化物进行物相分析 ,确认其主要物相为单斜晶系锰钾矿。利用锰的磁性质计算得到锰以Mn4 + 、Mn2 + 组合形式存在 ,结合电子探针微区化学成分分析计算出矿物的晶胞参数和样品的晶体化学式。该天然锰钾矿结晶粒度属于纳米级 ,其晶体结构中存在孔径不一的两种孔道 ,K+ 位于由 [MnO6]八面体所构筑的较大孔道内。天然锰钾矿具有表面吸附、氧化还原、离子交换、孔道效应和纳米效应等良好的环境属性。
XRD and IR analyses show that the main phase of Xiangtan manganese ore from Hunan Province which contains manganese oxides is monoclinic cryptomelane. The accurate crystal-chemical formulae of natural samples 1 # and 2 # are (K 0.51Na 0.13Ca 0.027)(Al 0.168Fe 0.091Zn 0.046P 0.043Ni 0.027Ti 0.021Mg 0.016) Mn 2+ 0.162 Mn 4+ 7.452O 16 and (K 0.57Na 0.034Ca 0.018) 0.622 (Mn 7.695 Ti 0.022 Cu 0.02 Ni 0.02Zn 0.006Al 0.003) 7.766, respectively, which are calculated by the combination of the magnetic system and electron microprobe analyses. This cryptomelane belongs to nano grade particles because the diameter of its crystal particles is between 30nm to 110nm as shown by Atomic Force Microscope (AFM). The parameters of crystal cell are a 0=0.9803 nm, b 0=0.2849 nm, c 0=0.9665 nm, β=91.2°, which are given by the correction of the Reitveld Powder Diffraction Profile Fitting Technique. There are two kinds of tunnels in the crystal structure, and K + ions are located in the larger tunnels constructed by octahedrons. Generally, the crystal-chemical characteristics of natural cryptomelane possess five favorable environmental properties, i.e., surface adsorption, redox, ion exchange, tunnel and nano particle effect.
出处
《岩石矿物学杂志》
CAS
CSCD
北大核心
2001年第4期477-484,共8页
Acta Petrologica et Mineralogica
基金
国家自然科学基金资助项目 (4 9972 0 17)
