HYDROGEN SUBSTITUTION IN LITHIUM-ALUMINOSILICATES
HYDROGEN SUBSTITUTION IN LITHIUM-ALUMINOSILICATES
复制标题
DOI：
10.1007/bf01115722
复制
发表时间：
1988-05-01
影响因子：
4.5
通讯作者：
NEEFF, R
中科院分区：
文献类型：
--
作者：
MULLER, G;HOFFMANN, M;NEEFF, R
石英和凯提石是二氧化硅晶型，具有相对致密的骨架，含有小的空洞。具有小电荷补偿性阳离子的铝硅酸盐，如锂、镁和锌，可以采用相同类型的结构，阳离子占据空隙。结果表明，石英型和钾钛矿型(Li，Mg_(0.5)，Zn_(0.5))AlSi_2O_6固溶体中的锂含量都能与热浓硫酸中的氢进行离子交换。这种离子交换是可以逆转的。在高温下，水可以不可逆转地从氢的形式中被赶走。离子交换和热脱水都不影响空间群对称性或骨架连接，但晶格参数的变化表明骨架发生了相当大的扭曲。热膨胀也与阳离子含量有很大的不同。数据表明，在脱水过程中，铝离子离开骨架进入空隙，从而为剩余骨架铝含量提供电荷补偿。
Quartz and keatite are SiO2polymorphs with relatively dense frameworks containing small voids. Aluminosilicates with small charge compensating cations such as lithium, magnesium and zinc can adopt the same types of structures with the cations occupying the voids. It 1s shown that the lithium content in both quartz- and keatite-type (Li, Mg0.5, Zn0.5)AlSi2O6solid solutions can be ion exchanged against hydrogen from hot concentrated H2SO4. This ion exchange can be reversed. At high temperatures water can irreversibly be driven off the hydrogen forms. Neither ion exchange nor thermal dehydration affects space group symmetry or framework linkage, but lattice parameter variations indicate considerable framework distortions. Thermal expansion also varies strongly with cation content. The data indicate that during dehydration aluminium ions leave the framework and enter the voids thereby providing charge compensation for the remaining framework aluminium content.[/p]