A procedure to remove unwanted content of Biuret in urea contained a substance comprising urea and biuret

摘要

1404098 Ion-exchange GUANOS Y FER-TILIZANTES DE MEXICO SA 16 May 1973 23272/73 Heading BIJ [Also in Division C2] An apparatus suitable for the purification of urea by contacting it with an ion-exchange resin in a batch process comprises a column 11, containing the resin 12 supported on graded sand 13, surrounded by a steam jacket 14 and provided with inlet and outlet lines 15 and 16 respectively. The lines 15 and 16 are provided with lines 17 for introducing backwash liquid at the lower end of the column and removing some from the upper end. An apparatus suitable for the continuous purification of urea comprises three columns 21, 22, and 23 provided at their lower ends with inlets 30, 31 and 32 respectively and at their upper ends with outlets 36, 37 and 38 respectively. The lower ends of columns 21, 22 and 23 are connected via lines 24, 26 and 28 respectively to the upper parts of columns 22, 23 and 21 respectively so that partially exhausted resin can be regenerated, and recycled. For Figure see next page