Synthetic swelling clay minerals

Synthetic swelling clay minerals made up of elementary three-layer platelets consisting of a central layer of octahedrally oxygen-surrounded metal ions (octahedron layer), said layer being surrounded by two tetrahedrally surrounded, silicon atom-containing layers (tetrahedron layers), a number of such elementary platelets being optionally stacked, wherein

• a) the dimensions of said platelets vary from 0.01 μm to 1 μm;
• b) the number of said stacked elementary three-layer platelets varies from one platelet to twenty platelets, while in said octahedron layer at most 30 at. % of the metal ions has been replaced by ions of a lower valency and in said tetrahedron layers at most 15 at. % of the silicon ions has been replaced by ions of a lower valency, such a replacement having taken place in at least one of said layers and said layers having a deficiency of positive charge because of the replacement;
• c) in said octahedron layer, magnesium, zinc, nickel, cobalt (II), iron (II), manganese (II), and/or beryllium are present as divalent ions;
• and lithium is present as monovalent ions;
• d) in said tetrahedron layer, silicon and/or germanium are present as tetravalent component and aluminum, boron, gallium, chromium, iron (III), cobalt (III) and/or manganese (III) are present as trivalent component;
• e) in that a part of the hydroxyl groups present in said platelets has been replaced by fluorine;
• f) in that a surface area of at least 150 m2 per gram is present in pores of at least 6 nm;
• and
• g) in that said clay minerals are pillared with oligomeric or polymeric hydroxy complexes of (metal) ions, such as aluminum, zinc, chromium and/or silicon.