EXTRACTION OF CYANAMIDE AND DICYANDIAMIDE FROM AMMONIACAL SOLUTION WITH ALIQUAT 336

Solvent extraction of cyanamide and dicyandiamide (1-cyanoguanidine) from aqueous ammoniacal solution with Aliquat 336, a mixture of trialkylmethylammonium chlorides (trialkyl = C-8-C-10, mainly capryl) dissolved in Shellsol T, has been studied. Extraction isotherms with different ionic forms of the anion exchanger are reported for separation of the compounds of interest, as well as for mixtures of the solutes. The search for an appropriate modifier to solve the apparent phase disintegration of the formed complexes results in a mixture of 10 % (v/v) 2- ethylhexanol and 30 % Aliquat in Shellsol T. With this phase the influence of temperature and extractant concentration and the effect of changing ammonia concentration in the feed solution have been investigated. A stoichiometric model was proposed and a temperature and concentration invariant 2:1 (solute: amine) complex was found for dicyandiamide. A temperature variant stoichiometric complex with cyanamide allows prediction of optimal separation conditions.