海泡石的化学成分研究

THE CHEMICAL COMPOSITION OF SEPIOLITE

本文通过两种不同成因海泡石化学成分特征的研究发现，热液型海泡石和沉积型海泡石的化学组成有较大差异，热液型纤维状海泡石ＭｇＯ、ＳｉＯ２含量高，Ａｌ２Ｏ３含量低，为富镁海泡石；沉积型粘土状海泡石ＭｇＯ、ＳｉＯ２含量低，Ａｌ２Ｏ３含量高，为富铝海泡石。而且，两种不同成因的海泡石结晶形态的差异与其化学组成密切相关；热液型海泡石Ｍｇ２＋、Ｓｉ４＋高，Ａｌ３＋低，接近理想值，易结晶形成长纤维状；而沉型积海泡石Ｍｇ２＋、Ｓｉ４＋较低，Ａｌ３＋高，结晶颗粒细小，为粘土状，但在电镜下观察仍呈纤维状。

By studying chemical composition of sepiolite of two kinds of mineralization,we found that there is an obvious difference in chemical composition between the thermatic sepiolite and sedimentary sepiolite.The thermatic fibrous sepiolites are ones of rich Magnesium,richened with Magnesium,silicon and few Aluminum,and the sedimentary clayey sepiolites are ones of rich Aluminum,have lower Magnesium,Silicon and higher Aluminum.So,we can conclude that there are close relations between difference of cyrstal outline and chemical composition of sepioilte.That is ,the sepiolites of rich Magnesium easily grow fibrous along direction of octahedral chain. But,the sepiolites of rich Aluminum grow clayey because of octahedral distortion by Aluminum instead of Magnesium.