IMPROVED SWELLABLE LAYER SILICATES

摘要

The invention relates to a swellable phylloscilicate on the basis of smectite or sepiolith/palygorskite for use in media that reduce swellability and that contain bivalent or polyvalent cations, characterized by a swelling volume of about 5 to 50 ml, measured by adding 2 g phyllosilicates (absolutely dry) to 100 ml water, and by a fineness of maximally 5 % by weight > 40 .mu.m or maximally 20 % > 20 .mu.m, as the dry screening refuse.