Prodn. of non-dusting alkaline earth fertiliser granules - by granulation of powdered alkaline earth mixture with magnesium salt soln. and/or sulphate waste liquor

• Main Authors: KRAUKE, WOLFGANG, SCHROEDER, UWE, UHLIG, HORST, NUERNBERGER, CHRISTIAN, KAHLE, KLAUS.., O-5400 SONDERSHAUSEN, DE, HERING, DIETER.NAT., O-7025 LEIPZIG, DE, BEYER, JOACHIM., O-7127 TAUCHA, DE
• Format: Patent
• Language: English; German
• Published: 17.01.1991
• Subjects: CHEMISTRY; FERTILISERS; FERTILISERS PRODUCING CARBON DIOXIDE; INORGANIC FERTILISERS NOT COVERED BY SUBCLASSES C05B, C05C; MANUFACTURE THEREOF; METALLURGY

Prodn. of non-dusting alkaline earth fertiliser granules with a particle size of 1-6.3 mm is effected by granulating a powdered mixt. of alkaline earths, e.g. MgCO3, CaCO3 and MgO, with an Mg salt soln. (I) and/or sulphite waste liquor (II) in an appts. comprising a mixer and a granulating drum. In the last third of the time in the drum, the granules are dusted with 10-20% of the powdered starting mixt. The finished granules are compacted on a vibratory sieve with a slope of 5-15 deg. and an energy input of 1-2 kW/m2 sieve surface. (I) is, e.g., a MgCl2 and/or MgSO4 soln. and is used in an amt. such that the molar ratio of free MgO to MgCl2 and/or MgSO4 is 2-12:1. (II) is used in an amt. of 200-250 l/t. The undersize particles from the sieve are recycled for dusting the granules.