Process for producing urea and biuret

A process for the production of urea wherein:

• the production of urea includes the concentration of an aqueous urea solution by means of a process of crystallization, which is performed in a urea crystallization section, obtaining solid crystals of urea and a urea crystallization purge aqueous phase comprising urea, water and biuret, which is purged from the urea crystallization process;
• at least a portion of said urea crystallization purge aqueous phase is further processed in a high-biuret urea processing section wherein a high-biuret urea is produced in a solid form, said high-biuret urea containing at least 55% by weight of biuret;
• wherein urea is produced at a high pressure of synthesis in a urea synthesis section, obtaining a synthesis effluent containing urea, water and unconverted ammonium carbamate;
• said effluent is processed in a recovery section at one or more pressure levels lower than the synthesis pressure to recover unconverted reagents which are recycled to the synthesis section, and said aqueous urea solution is obtained in the recovery section.