PROCEDEU DE OBTINERE A CARBONATULUI DE GUANIDINA

摘要

Guanidine carbonate (I) is recovered from dil. aq. solns., which contain guanidine, urea and its hydrolysis prods., NH3 and CO2, by (a) evapn. of the solns. at 80-130 degrees C until the (I) content is not 20 g/l., and the content of pyrolysis prods. is 28 g/l. at an evapn. temp. of 80 degrees C or 128 g/l. at an evapn. temp. of 130 degrees C, the duration of evapn. at 130 degrees C being is nt >6 hours, (b) removal of the ppd. pyrolysis prods., (c) cooling to is not >45 degrees C, (d) addn. of NH3 to bring the NH3 content to 15-30 wt. % (20-25 wt. %), and (e) sepn. of pptd. (I), opt. followed by washing with NH4OH. (I) is obtd. in high purity; evapn, in vacuum is avoided; less NH3 is needed.