Abstract: In a process for the production of guanidine nitrate from urea and ammonium nitrate, in the presence of SiO.sub.2 catalyst under increased temperature whereby the initial mixture of urea and ammonium nitrate contains an excess of ammonium nitrate which is kept practically constant up to the conversion of the total urea portion during the operation up to the final phase, the catalyst is removed by filtration. It is slurried up several times by means of molten ammonium nitrate or a mixture of ammonium nitrate/urea at 135.degree.-200.degree. C. together with the adherent components like ammonium nitrate, guanidine nitrate and by-products like triazenes. Hereby the components adherent to the catalyst are replaced and removed by subsequent filtration.

Abstract: In a process for the production of guanidine nitrate from a mixture of urea and ammonium nitrate in the presence of a catalyst containing silicium oxide at increased temperature, the initial mixture of urea and ammonium nitrate having an excess of ammonium nitrate, urea is added stepwise to the existing mixture of urea and ammonium nitrate and the catalyst during the procedure in quantities so that the weight ratio of urea: ammonium nitrate is permanently in favor of an excess of ammonium nitrate. The weight ratio is practically maintained during the process and is increased only in the final phase. An apparatus for the performance of the process of the invention comprises a reactor system including one or several substantially horizontal, tubular, heatable reactors in a series. The reaction mass is introduced together with the catalyst in the form of a melt and moved through the reactor system by means of a stirrer and a conveyor.