Method for the continuous production of a mixture with a pre-defined ratio of fully colored and non-colored fertilizer particles and system and use thereof

A method for a continuous production of a mixture of fully colored and non-colored fertilizer particles having a median size of about 1 to 6 mm with a predefined ratio of the fully colored and non-colored fertilizer particles, starting from a stream A of non-colored fertilizer particles, comprising steps of:

• a1) continuously separating the stream A of the non-colored fertilizer particles into a stream C of non-colored fertilizer particles and one or more parallel streams B1, B2, . . . Bn of non-colored fertilizer particles in the predefined ratio;
• b1) continuously coloring the non-colored fertilizer particles from the parallel streams B1, B2, . . . Bn obtained from step a1) with a non-rub-off coloring agent, such that the non-colored fertilizer particles become fully colored;
• c1) continuously joining the parallel streams B1, B2, . . . Bn, now comprising the fully colored fertilizer particles, obtained from step b1), with the stream C of the non-colored fertilizer particles downstream of the separation step a1), thereby obtaining the mixture of the fully colored and non-colored fertilizer particles, and;
• d1) optionally, processing the mixture of the fully colored and non-colored fertilizer particles, obtained from step c1).