I am aware the discussion is about KSCN used in photography. However I noticed that some of the posters are quite knowledgeable chemists that may be able to help with a roadblock in the chemical process that I am a part of that uses Ammonium thiocyanate. We have a solution at the end of the process containing about 3g/L of Rhenium as perrhenate in an ammonium thiocyanate solution. I have found a method that can reduce the Rhenium content to approx. .1g/L, but in order to proceed I need to acidify the solution to below a pH of 2. I have been told by some of my my co-workers that the addition of acid will result in the release of HCN. I understand thier logic but don't fully agree, thats why I wanted to pose this question to this thread to get some outside opinions of the situation.