Abstract: A process is disclosed for the preparation of milled crude potash salts containing kieserite, whereby the crude potash salt is conditioned at first with a chemical conditioning agent and subsequently with an auxiliary conditioning agent, whereupon the crude potash salt is fed to an electrostatic free fall separator.

Abstract: An elecrtrostatic separation of paper- and synthetic plastic material-containing mixtures is performed by comminuting the mixture, triboelectrically charging the comminuted mixture, and supplying it into a free-fall separator, wherein a paper-enriched and a synthetic plastic material-enriched fraction are produced, and in some cases they can be treated in a second electrostatic separation step to pure products.

Abstract: An arrangement for feeding a fine-particle material to be separated to an electrostatic free-fall cutter is formed as a funnel with braking inserts and inclined walls whose edges limit a small elongated rectangular discharge slot, wherein a greater wall is inclined to an opposite vertical wall which has an inclined downwardly directed guiding member, and a wedge-shaped projection with an upper horizontal surface is located at the lower edge of the inclined wall and extends into the discharge slot.

Abstract: An electrostatic free-fall separator has a feeding arrangement located upstream of the separator for feeding of fine-particle material to be separated into the electrostatic free-fall separator, wherein the feeding arrangement is formed as a funnel with braking inserts of an electrically insulated material and has walls limiting at their lower edge a longitudinal outlet slot, wherein the funnel has an inlet which is formed by one wall portion which is parallel to the outlet slot and an opposite inclined guiding surface with a lower edge extending parallel to the one wall portion so as to limit simultaneously a passage leading to the outlet slot, and two substantially vertical electrodes are arranged below the passage at a distance from one another which is smaller than the width of the passage.

Abstract: A carnallite-containing crude salt is separated into a carnallite fraction, a sylvite fraction and an abandonable residue by grinding the salt to an average particle size of about 1.5 mm., conditioning the particles in a conventional manner with from 5-300 g/t of a conventional conditioning agent adjusting the relative humidity of the conditioned particles to 5-25%, and subjecting the resulting particles to electrostatic separation in two stages, wherein in the first stage the particles are subjected to a high voltage electric field having a field length of 0.4 to 1.2 m to separate a carnallite fraction by imparting to the carnallite fraction a high sidewards velocity relative to the initial downward velocity upon entering the field, thereby causing deflection of the carnallite away from a middlings fraction, and wherein in the second stage the first stage middling fracton is subjected to a second high voltage electric field having a field length of 1.5 to 2.

Abstract: Crude potash salt is conditioned for separation into its components by means of an electrostatic field by grinding the salt to disintegration and contacting the ground salt with a conditioning agent, such as salicylic acid, which has been converted to the gaseous state, such that the conditioning agent draws up onto the surfaces of the salt crystals by absorption. The quantity of the conditioning agent employed is adjusted by varying the evaporation temperature and/or by varying the volume of heated air and/or inert gas, serving as a carrier material.