Abstract: A process is proposed for the preparation of a powder comprising one or more derivatives of glycine-N,N-diacetic acid and/or one or more derivatives of glutamine-N,N-diacetic acid with a degree of crystallinity of a ?30%, starting from an aqueous solution comprising the one or more derivatives of glycine-N,N-diacetic acid and/or the one or more derivatives of glutamine-N,N-diacetic acid in a concentration range from 20 to 60% by weight, based on the total weight of the aqueous solution, where the aqueous solution is concentrated in a first process step in an evaporator with rotating internals, which are arranged at a distance relative to the inside wall of the evaporator of ?1% of the diameter of the evaporator, to give a crystal slurry with a solids concentration in the range from 60 to 85% by weight, based on the total weight of the crystal slurry, and where in a second process step the crystal slurry is left to ripen in a paste bunker and then in a thin-film contact dryer, and where the residence time i

Abstract: A process is proposed for the preparation of a powder comprising one or more derivatives of glycine-N,N-diacetic acid and/or one or more derivatives of glutamine-N,N-diacetic acid with a degree of crystallinity of ?30%, starting from an aqueous solution comprising the one or more derivatives of glycine-N,N-diacetic acid and/or the one or more derivatives of glutamine-N,N-diacetic acid in a concentration range from 20 to 60% by weight, based on the total weight of the aqueous solution, where the aqueous solution is concentrated in a first process step in an evaporator with rotating internals, which are arranged at a distance relative to the inside wall of the evaporator of ?1% of the diameter of the evaporator, to give a crystal slurry with a solids concentration in the range from 60 to 85% by weight, based on the total weight of the crystal slurry, and where in a second process step the crystal slurry is left to ripen in a paste bunker and then in a thin-film contact dryer, and where the residence time in t

Abstract: A process is proposed for the preparation of a powder comprising one or more derivatives of glycine-N,N-diacetic acid and/or one or more derivatives of glutamine-N,N-diacetic acid with a degree of crystallinity of ?30%, starting from an aqueous solution comprising the one or more derivatives of glycine-N,N-diacetic acid and/or the one or more derivatives of glutamine-N,N-diacetic acid in a concentration range from 20 to 60% by weight, based on the total weight of the aqueous solution, where the aqueous solution is concentrated in a first process step in an evaporator with rotating internals, which are arranged at a distance relative to the inside wall of the evaporator of ?1% of the diameter of the evaporator, to give a crystal slurry with a solids concentration in the range from 60 to 85% by weight, based on the total weight of the crystal slurry, and where in a second process step the crystal slurry is left to ripen in a paste bunker and then in a thin-film contact dryer, and where the residence time in t

Abstract: Improved process for the preparation of granular N-alkylammoniumacetonitrile salts I R2R3N+R1—CR4R5—CN Y−  (I) where R1 to R5 are hydrogen or organic radicals, and Y− is a sulfate or hydrogensulfate anion, from an aqueous solution of the compound II R2R3N+R1—CR4R5—CN R6O—SO2—O−  (II) where R6 is C1- to C4-alkyl, which comprises evaporating this aqueous solution at a temperature of from 80° C. to 250° C. and a pressure of from 10 mbar to 2 bar to give a melt, then allowing the melt to solidify, where, during or following the evaporation, customary carrier materials and/or auxiliaries can be added, and the resulting solidified compound I is converted into the desired granular form.