Abstract: The invention relates to a process for preparing purified, virtually odorless, solid benzoic acid obtained from toluene by oxidation with a gas containing molecular oxygen, by means of a treatment using an inert gas or gas mixture, wherein the benzoic acid to be purified is supplied in a liquid state to a fluid or spouted bed granulator in which the prevailing temperature is below the solidification temperature of the benzoic acid and in which the benzoic acid is treated, during and possibly after the granulating process, with the said gas or gas mixture, the impurities present being taken up in whole or in part in the gas or gas mixture, upon which the benzoic acid thus purified is removed from the fluid or spouted bed device.

Abstract: Process for preparing magnesium nitrate hexahydrate without the need for filtering aids. A process for preparing magnesium nitrate hexahydrate essentially comprises: (a) forming a magnesium oxide or magnesium carbonate suspension in melted magnesium nitrate hexahydrate at a suspension temperature in excess of 90.degree. C.; (b) adding a nitric acid solution to the suspension while stirring thereby forming a reaction mixture containing additional magnesium nitrate hexahydrate; (c) filtering the liquid reaction mixture to obtain a clear magnesium nitrate hexahydrate filtrate; (d) discharging as product a part, corresponding to the amount of magnesium oxide or magnesium carbonate introduced, of the liquid magnesium nitrate hexahydrate obtained as clear filtrate; (e) utilizing the remaining part as liquid medium for the conversion of magnesium oxide or magnesium carbonate with nitric acid.

Abstract: A method for producing urea prills by passing molten droplets of substantially water free urea downwardly through a cooling zone countercurrent to a cooling gas. A dispersion of crystalline particles is maintained in at least a portion of the cooling zone, the crystalline particles having average dimensions of between 2 and 10 microns and being dispersed in the cooling gas in a quantity of between about 8 and 25 mg per m.sup.3 of the cooling gas at ambient temperature and pressure, whereby urea prills, built up of relatively small crystallites with random orientation having improved impact strength are formed.

Abstract: An improved method for spraying molten material in order to obtain solidified grains or prills. Molten material, such as NPK-fertilizer is fed into a symetrical rotating reservoir which rotates about a vertical axis and whose upright walls are provided with apertures for spraying. The interior of the rotating reservoir accommodates a member provided with blades, which member rotates at a speed different from that of the reservoir. The sprayed molten material cools while falling to form solid round prills. The blades inside the reservoir rotate at a speed at least 1.5 times greater than the speed of rotation for the reservoir.