Alkali cyanide soln. - produced by reacting alkali hydroxide soln. with hydrogen cyanide obtained by thermolysis of formamide

摘要

Prodn. of aq. alkali cyanide solns. by reacting alkali hydroxides with HCN, obtained by thermal, catalytically accelerated splitting of formamide under reduced press; is improved in that up to 95% of crude HCN is directly absorbed by an aq. alkali hydroxide soln. without increasing the press. to atmospheric press; whilst the press of the remaining gases is increased to atmospheric press. only subsequently whereby the liquifaction of the residual HCN is effected; the latter is then reacted with the alkali hydroxide soln. The volume of the gases to be compressed to the atmospheric press. is constantly reduced by the absorption of the bulk of HCN when still under reduced press. whereby the size of the compressor can be reduced and the compression cost is dimished.