Process for making a powder or granule comprising at least one chelating agent

A process for making a powder or granule comprising

• (A) in the range of from 40 to 85% by weight of at least one chelating agent selected from methyl glycine diacetic acid (MGDA), glutamic acid diacetate (GLDA), iminodisuccinic acid (IDS), and/or their respective alkali metal salts,
• (B) in the range of from 15 to 60% by weight of at least one homo- or copolymer of (meth)acrylic acid, partially or fully neutralized with alkali, and/or polyaspartates, percentages referring to the solids content of said powder or granule,
• said process comprising the steps of
• (a) mixing in the range of from 80 to 99% by weight of the at least one chelating agent (A) and in the range of from 1 to 20% by weight of the at least one homo- or copolymer (B) in the presence of water,
• (b) removing most of said water by spray-drying or spray granulation,
• (c) optionally, purifying the composition obtained from step (b), and
• (d) physical mixing of the composition obtained from step (b) or step (c) with additional polymer in the range of rom 1 to 50% by weight of at least one homo- or copolymer (B),
• (e) optionally, physical mixing of the composition obtained from step (b), (c) or (d) with at least one organic acid with a molecular weight of not more than 500 g/mol,
• percentages referring to the solids content of said powder or granule, wherein addition of polymer by physical mixing in step (d) and optional addition of organic acid in step (e) are done in a way such that the total amounts of chelating agent (A) and polymer (B) defined above are reached.