A process for the preparation of a reversibly swellable grossflaechig crystalline mineral species with three layer formed by mutually dissolved crystal layers and mineral substance according to the method

摘要

1. Method for the manufacture of a mineral substance based on a reversibly expandible, three-flake mineral of crystalline form of large surface area, with separated crystal flakes, characterised in that in the 1st stage thermally expanded vermiculite or thermally expanded hydro-mica, these minerals also having intercrystalline embedded non-expandible mineral, of a grain size range of approximately 0.5 to 4 mm, is stirred in a large excess of water, then in a flowing current for a residence time of approximately 10 to 60 sec a flotation separation of the expanded, floating vermiculite or hydro-mica from non-expanded components takes place, then in the 2nd stage the separated, expanded vermiculite or hydro-mica, with a water content of approximately 90% based on the moist weight, is freed of the residual air held between the lamellae by storage under movement and at the same time the aqueous expansion of the mineral to its final state takes place, then in the 3rd stage a preliminary crushing is brought about by intensive movement of the mixture and at the same time its state of high intrinsic viscosity is destroyed (by thixotropy), in the 4th stage the mixture is ground under turbulent flow conditions to a grain size with a particle diameter of 0.1 to 0.3 mm, the thickness of the platelet-shaped particles being up to 200 micron, then in the 5th stage under laminar flow conditions at speeds of the material to be crushed relative to the crushing body of 10 to 120 m/sec grinding takes place to give over 50 percent by weight of tabular, extremely thin, uniformly even particles with a thickness of 0.5 to 10 micron and with surface dimensions corresponding to an equivalent diameter of 10 to 200 micron and a ratio of particle thickness : equivalent diameter equal to or less than 1 : 10, and then in the 6th stage by hydro-extraction the solid matter content of the mixture is brought to approximately 40%, and the porous product is collected, or if required is dried.