Abstract: A process for preventing the formation of dust during the loading of sulfate fertilizer granulates includes spraying a high-percent aqueous solution of urea onto the fertilizer granulates. The amount of aqueous solution sprayed ranges from 4 to 8 kg of solution per ton of granulate. The concentration of urea within the solution is between 50% and 80% by weight.

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: Process for producing potassium magnesium phosphate by reacting basic magnesium compounds with phosphoric acid or phosphates in the presence of potassium sulfate from a mother liquor containing per 1000 g water up to 150 g magnesium sulfate and up to 120 g potassium sulfate. Precipitation forms with addition of calcium oxide or hydroxide equimolar to present magnesium sulfate and after phosphoric acid adjustment of the pH to 2-4, mechanical separation and addition of potassium sulfate and basic magnesium compounds, the desired product results.

Abstract: For the production of potassium magnesium phosphate from phosphoric acid, potassium salts and basic magnesium compounds, these are reacted in a mixture of recycled mother liquor from the potassium magnesium phosphate crystallization and of fresh water, with adjustment of the pH-value of the reaction mixture to 7.2 up to 8.5 through addition of quickly reacting basic compounds, in the presence of potassium magnesium phosphate seed crystals, whereupon the product is separated from the mother liquor and from this a part is recycled to the process start, and the rest is removed.

Abstract: Plastic hose means, preferably of high pressure polyethylene admixed with a flame retarding agent and treated to render the same antistatic and characterized by a resistance to tearing of at least 15 N/mm.sup.2, an extension of at least 450 percent, a resistance to piercing of at least 1.5 J and a resistance to continued tearing of at least 17 N/mm, are disclosed, as is a process for using the hose means for filling the space between the rock face of a mine or tunnel and the supporting structure therefor.

Abstract: A process for selectively recovering coarse crystalline K.sub.2 SO.sub.4 from a crystallizer is disclosed. A classifier comprising an elongated cylindrical vessel which is located separate from the crystallizer is employed in the process. Crystallization is effected in the crystallizer and supernatant liquor recovered as overflow during crystallization is passed from the crystallizer into the lower portion of the elongated cylindrical vessel. Slurry is recovered from the bottom of the crystallizer and introduced into a middle portion of the elongated cylindrical vessel. Coarse crystalline K.sub.2 SO.sub.4 falls to the bottom of the elongated cylindrical vessel and is recovered therefrom. Fine crystalline K.sub.2 SO.sub.4 is entrained in the upwardly flowing liquor and passed upwardly therewith. The upwardly flowing liquor and fine crystalline K.sub.2 SO.sub.4 are withdrawn from the top of the elongated cylindrical vessel and recycled to the crystallizer.