层间阴离子对水黑云母层间水赋存状态的影响

EFFECT OF INTERLAYER CATIONS ON THE EXISTING STATE OF INTERLAYER WATER IN HYDROBIOTITE

水黑云母是云母一蛙石的1：1规则间层矿物。本文通过阳离子交换方法得到多种单离子型（Na+、K+、Ca2+、Mg2+、Ba2+、Cu2+、Zn2+、Co2+和Al3+）水黑云母。利用X射线衍射分析和热分析，探讨了层间阳离子类型对水黑云母层间水赋存状态的影响。研究表明，在层间均为两层水的情况下，水黑云母中蛙石层间域厚度与层间阳离子的离子半径大小成正相关关系。层间脱水温度高低与层间阳离子的离子电势（电荷／离子半径）大小成正相关关系。例外的情况出现在Al3+型水黑云母中。Al3+的离子电势很高，但其层间脱水温度却没有预计的那么高。原因可能是Al3+在层间水解为Al（OH）2+或（和）Al（OH）．从而使有效的离子电势降低。

Hydrobiotite is a regular 1:1 interstratifled mineral composed of mica and vermiculite.Homoionic (Na+, K+, Ca2+, Mg2+, Ba2+. Cu2+, Zn2+, Co2+ and Al3+ ) hydrobiotite is obtalned by cation exchange react1on. With X-ray diffractometry and differential thermogravimetry, the effect of lnterlayer cations on the existing state of interlayer water is discussed in thls paper. The results indicate that at two-layer interlayer water, the size of interlayer space in vermiculite unit is posltively related to the ionlc radius of interlayer cations. The dehydration temperature is positively related to the ionic potential of the interlayer cations. Exception occurs in Al3+ -hydrobiotite, wheredehydration temperature is much lower than what is expected though the ionic potential of Al3+ ionis very high. It is postulated that Al3+ ion in the interlayer is hydrolyzed to Al(OH)2+ and/orAl(OH), whlch reduces the effectlve ionic potential of Al3+ ion.