Objective:Glauconite is precipitated in neritic environment and usually using as an indicator,can turn mature till 1Ma long.The experiments were carried out in a drying oven with a the temperature at constant 50℃,a montmorillonite which has a low iron content and varieties solution as the initial material,the solution was 0.1 mol/LFe3+,0.2mol/LK+ adjusting to different pH、Eh.The products were analyzed by powder X-ray diffractometry (XRD),Frourie Transform Infrared (FTIR) spectrometry,Electron Spin Resonance (ESR) spectrometry and Scanning Electron Microscopy (SEM).The morphological observation of products have been carried out under the SEM and suggested the new forming of flake like products.Qualitative analysis of products suggested that the main phase was mica group mineral and d060 value suggested the present of glauconite (0.1520 nm) and/or Fe-illite (0.1498nm).The assemblage of Glauconite and Fe-illite formed in acidic solution,while the Fe-illite and the mixlayer Fe-illite and montmorillonite were formed in the neutral and alkali solutions.Furthermore,the Fe3+ Fe3+ OH,Al3+Fe2+ OH and/or Mg2+ Fe3+ OH (3550 ～3562cm-1) stretching vibration was present in FTIR spectra of products formed in acidic solution,as well as the g =1.978 signals in ESR suggesting that ferric iron entered the octahedral position of TOT sheets.The bands of Al3+ Fe2+OH、Mg2+ Fe3+ OH (3550 ～3562 cm-1) and Al3+ Fe3+ OH (870cm-1) vibration were found present in products formed in neutral and alkaline solutions.The experimental simulation suggested that the pH and redox conditions of environment was vitally significant and constrained the reaction product.Therefore,glauconization and illitization has occured under the different conditions,glauconization preferred to occur in an acidic environment but illitization more preferred to occur in a near neutral to alkaline environment.Methods:Analytical reagents formulated as FeCl3 and KCl,concentration is 0.02 ～ 0.1 mol / L and 0.05 ～0.2mol / L in solution as the source of Fe3 + and K + ion.pH of the solution is between 6.3 ～ 10.3,pH values adjusts to NaHCO3 and KOH.The different pH as the main condition set up eight groups of the experiment.The experiment is completed in a thermostatic oven,set the ambient temperature is 50℃,the amount of each experiment montmorillonite dosage is 0.5g,solid—liquid ratio of 1:100,and the reaction time is 60 and 150 days,every 50 days change fresh solution.The fresh solution have the same pH、EH and solution dosage as initial solution The techniques of testing include powder X-ray diffractometry (XRD),Electron Spin Resonance (ESR) spectrometry and Fourier Transform Infrared (FTIR) spectrometry were used to study the obtained chromium bearing montmorillonites.Results:XRD pattern of the reaction products show that belongs to the 001 diffraction peak of montmorillonite significantly decreased or disappeared,all appear mica minerals characteristic diffraction about the 1 nm or so diffraction of d001 and the 0.1520 diffraction peak of d060 (0.1MPH6.3T50 ～ 0.1MPH7.1T50),the reaction products in the weakly alkaline and alkaline environment(0.1MPH7.3T5 ～ O.1MPH10.3T50) appear d001 value 1.03、1.15、1.16、1.22 nm.The corresponding,which appear the AlFe2+ OH、Fe3+ Mg2+ OH、Fe3+ Fe3+ OH absorption peaks or shoulder peaks on the reaction product infrared absorption spectrum,the sample of 0.1 MPH (6.3 ～ 6.9) T50 appear 3527 and 3550cm-1 absorption peaks that attribute to the stretching vibration of Fe3 + Fe3 + OH、Mg2+ Fe3+ OH.In different pH solution,weakly acidic to neutral environment (pH ＜ 7.1) is the appropriate trigger glauconitization;alkalescent to alkaline environment is preferentially to form Fe-illite contained intumescent layers and mixed-layer clay mineral of Fe-illite and montmorillonite,which means the alkaline condition is not preferable to glauconitization,but it may form the precursor of glauconite,Fe-illite or mixed-layer clay mineral.Conclusions:In the montmorillonite glauconitization simulation experiments,pH of the solution is the most important factor apart from the components of solution.In acidic conditions and neutral (pH =6.3 ～ 7.1),glauconitization is easy to happen,in slightly alkaline and alkaline conditions(pH =7.3 ～ 10.3),a small amount of Fe3+ can enter into the montmorillonite octahedral vacancy,K + is difficult to enrich interlayers and has occured iron illitization.Fe3+ can enter into montmorillonite octahedral structure at low temperatures in glauconitization process.The glauconitic montmorillonite or iron—potassium rich illite are formed in this process,then part of Fe3+ is reduced to Fe2 + on the surface and in the structure of the above minerals in the subsequent geological processes,which become green gradually and form a mature glauconite.%海绿石是一种浅海相沉积指示矿物,形成成熟的海绿石需1Ma.本文以含铁量很低的蒙脱石和0.1 mol/LFe3+、0.2mol/LK+的离子溶液分别为初始物质,在50℃恒温环境和不同的pH、Eh条件下,模拟海绿石化过程,并通过XRD、FTIR、SEM、ESR等检测反应产物.研究发现,在SEM下观察到球形纳米颗粒的海绿石出现;同时XRD谱图上除出现云母类矿物的001衍射峰外,还出现d值为0.1520nm和0.1498nm的代表海绿石和铁伊利石的060特征衍射峰.pH和氧化还原条件对产物的影响比较显著,pH为酸性时出现海绿石和铁伊利石的组合,其红外吸收谱中出现AlFe2+ 0H或Mg2+ Fe3+ OH(3547 ～3562cm-1)、Fe3+ Fe3+ OH的伸缩振动峰,与之相应的ESR中出现g=1.978的八面体位Fe3+的共振峰;当pH介于中性的时候,红外光谱谱图上出现明显的AlFe2+ OH、Mg2+ Fe3+ 0H(3550 ～3562cm-1)和Al3+ Fe3+ OH (870cm-1)振动;pH为碱性时,出现Fe3+ Mg2+OH(3560cm-1)振动;上述红外吸收振动的出现表明Fe3+已经进入了蒙脱石结构的八面体位.蒙脱石在上述条件下发生明显的改变,发生海绿石化或铁伊利石化,pH和氧化还原条件对结果的影响比较显著,酸性的环境中海绿石化显著,而中性至碱性的环境则发生铁伊利石化.
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