Abstract: A method for producing a modified smectite or smectite-containing substance including treating a non-activated smectite or substance with a water soluble activating agent and polymer in a two stage process, the first stage including adding 0-3.0% of the activating agent and 0.05-1.0% of the polymer, by weight, and in a second stage adding 0-5.0% of the activating agent 0.3-5% of the polymer, by weight, to the mixture of the first stage, wherein at least a part of the polymer is added as a dry solid and the water in the first stage is at least 20% by weight and at most 50% by weight in the second stage.

Abstract: The present invention relates to a method for producing a modified smectite or smectite-containing substance capable of forming gels which are not longer thixotropic, have a stable cross-linked structure and adhesive characteristic and are capable of taking up and releasing water in a reversible manner by treating a non-activated smectite or smectite-containing substance with a water soluble activating agent and with a water soluble polymer capable of reacting with said smectite, wherein 0-6% by weight, calculated on the weight of the smectite, of the water soluble activating agent and 0.

Abstract: The invention relates to a clay-containing mixture or blend capable of forming a moisture resistant gel, which comprises a powdered or ground smectite and/or a smectite-containing natural rock and at least 0.8–10% by weight, calculated for the smectite content, of an at least partially water-soluble and/or water swellable polymer and optionally at least 0.5% by weight of a solid activating agent. Such a mixture may also additionally comprise as a diluting agent more than 0.5% by weight of one or more solid inert filler(s); this diluted version is termed in the specification as a blend.

Abstract: The invention relates to a clay-containing mixture or blend capable of forming a moisture resistant gel, which comprises a powdered or ground smectite and/or a smectite-containing natural rock and at least 0.8-10% by weight, calculated for the smectite content, of an at least partially water-soluble and/or water swellable polymer and optionally at least 0.5% by weight of a solid activating agent. Such a mixture may also additionally comprise as a diluting agent more than 0.5% by weight of one or more solid inert filler(s); this diluted version is termed in the specification as a blend.

Abstract: A dry mixture of (a) powdered or ground smectite and/or a smectite-containing natural rock, wherein the smectite is in an inactive state, (b) 1-10% by weight of a water-soluble polymer and (c) 0.8-6.0% by weight of a powdered activating agent can be combined with soil and water to provide a gel which is a barrier composition. The mixture may additionally contain a diluting agent, so as to form a dry blend, where the blend may likewise be combined with soil and water to provide a gel which is a barrier composition. The blend may be used to provide for water-tight insulation of vasins, damps and other objects exposed to damaging effects of water, and may also be used as a sealing for deponies, as a protecting layer for articles exposed to acidic liquids, and as a filling agent for cavities and cracks on articles exposed to water.

Abstract: The present invention relates to a method for producing a closing layer which improves the water and nutrient retention of soils, particularly of sandy soils, characterized in that a layer of clay mineral/polymer gel capable of binding and releasing water in a reversible manner is introduced into the soil, preferably 20-60 cm below the soil surface, in such a way that a clay mineral is reacted either before or after or during activation in the presence of water, with 0.

Abstract: A method is disclosed for improving the strength and impermeability of soils or engineering structures, which comprises the steps of:(a) applying to the site of the soil or of the engineering structure, an alkaline water glass solution comprising water glass in an amount of 15 to 40% by weight, calculated as dry substance;(b) allowing a time period to pass sufficient to permit the alkali present in the water glass solution to move by diffusion;(c) applying to the same site as in step (a), a silicic acid sol comprising SiO.sub.

Abstract: The invention relates to a process for the preparation of clay mineral-containing gels with stabilized structure and reversible water absorption ability.According to the invention an aqueous suspension containing a thixotropic, activated, swelling clay mineral of three-layer structure and/or a swelling chain silicate is treated with a water soluble polymer capable of reacting with the clay mineral and/or chain silicate, the clay mineral:polymer:water ratios are determined at which the resistance of medium of the resulting suspension is at least ten times higher than that of the initial, polymer-free suspension, and then the components are reacted with each other in the pre-determined ratios.