Abstract: Process for the production of an aqueous stream comprising melamine and aldehyde in which a melamine comprising aqueous stream is contacted with an aldehyde comprising stream, the melamine comprising aqueous stream originating from a melamine plant, and process for the production of an aqueous stream comprising melamine, urea and aldehyde in which a melamine comprising aqueous stream and a urea comprising stream are being contacted with an aldehyde comprising stream, the melamine comprising aqueous stream originating from a melamine plant.

Abstract: The invention relates to a process for separating NH3 from a mixture containing NH3, CO2 and H2O which comprises an NH3 rectification step carried out in a NH3 separation device to which one or more streams containing NH3, CO2 and H2O, including the mixture, are supplied, with a stream consisting substantially of gaseous NH3 being formed in the NH3 separation device, separated from the mixture and discharged. In the process according to the invention a condensation step is carried out on at least one of the stream consisting substantially of gaseous NH3 or the one or more streams containing NH3, CO2 and H2O supplied to the NH3 separation device, in which at least a part of the existing CO2 is converted to a liquid phase.