Attapulgite clay

Introduction to attapulgite clay

The attapulgite clay is a kind of clay mineral consisting mainly of attapulgite. The attapulgite is a kind of crystalloid hydrous magnesium-aluminum silicate mineral having a special laminated chain structure, in which there is a crystalline lattice displacement existed. Thus it makes the crystals contain uncertain quantities of Na+, Ca+, Fe3+ and Al existed in the shape of needles, fibers or fibrous clusters. The attapulgite has very good colloidal properties such as: specific features in dispersion, high temperature endurance, salt and alkali resistance, and also high adsorbing and de-coloring capabilities. Furthermore, it has certain plastic and adhesive characters. Its ideal molecular formula is Mg5Si8O20 (OH)2 (OH2)4 · 4H2O. The structure is somewhat between laminated and chain structure. The attapulgite looks like soil, and compact blocks which are found in the sedimentary rocks and the weathering crust. The minerals are white, hoar, caesious or celadon, or with some dim mercerization in color. The clay is fine and a bit greasy smooth, light in weight, crispy, and the fractured surface is like shells or in irregular shapes. The attapulgite has strong ability to absorb water. When it is wet, it shows plastic and adhesive properties; and when it gets dry, it dose not shrink much and does not show cracks. When it is soaked in water, it collapses. The soliquid, when it contacts with electrolytes, does not become flocculence and precipitates.