Abstract: An electrostatic separator of the free-fall type for classifying triboelectrically charged substance mixtures. This separator has a separate voltage source connected to each of the electrodes forming a pair of electrodes in such a way that the one voltage source supplies a positive voltage against ground potential and the other voltage source supplies a negative voltage against ground potential. This causes the potential difference against ground to be equal to zero in the center of the separator.

Abstract: Plastic mixtures, in particular those of a similar density such as polyethylene and polypropylene, are separated electrostatically, whereby prior to charging, the mixture is subjected to a surface treatment.

Abstract: Plastic mixtures, in particular those of a smilar density such as polyethylene terephthalate and polyvinyl chloride, are separated electrostatically, whereby the mixture, for triboelectric charging, is subjected to a thermal treatment.

Abstract: Plastic mixtures are split up into the individual components by a process combining density separation with electrostatic separation, and includes a special surface treatment which takes place prior to the electrostatic separation.

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: 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.