화학공학소재연구정보센터
Minerals Engineering, Vol.105, 19-21, 2017
Free cyanide analysis by silver nitrate titration with sulfide ion as interference
In cyanidation process, the free cyanide concentration is the main variable that controls the efficiency of the process, and the plant operators determine it by silver nitrate titration. If sulfide ion is present in the solution the free cyanide concentration cannot be determined by titration as the silver added in the titration reacts with the sulfide ion to form a black solid (silver sulfide) that hinders the visual detection of the titration endpoint. This work proposes the potentiometric detection of the endpoint of the titration and demonstrates, thermodynamically and with analyses performed in synthetic solutions, that it is possible to determine both, sulfide and cyanide in the solution, even if the endpoint of the titration cannot be visually detected. (C) 2017 Elsevier Ltd. All rights reserved.