• To participate in the 911Metallurgist Forums, be sure to JOINLOGIN
  • Use Add New Topic to ask a New Question/Discussion about Leaching.
  • OR Select a Topic that Interests you.
  • Use Add Reply = to Reply/Participate in a Topic/Discussion (most frequent).
    Using Add Reply allows you to Attach Images or PDF files and provide a more complete input.
  • Use Add Comment = to comment on someone else’s Reply in an already active Topic/Discussion.

Bluish-green colour observed at the base of the pregnant sol ... (2 replies)

1 month ago
magwazasammy86 1 month ago

Hi everyone.

We have a heap leach plant at our mine and we have oxide material from a mine dump.We are irrigating the using drip emitters sodium cyanide solution. The problem we are currently facing is that we are noticing the bluish-green colour at the base of the pregnant solution pond.Where could that colour be coming from?How best can we remove it?All your views and opinions are most welcome.

Thank you


1 month ago
ChrisBucknell 1 month ago

it is possibly the acid mine drainage from the oxid dump making into the PLS pond. You need to raise the pH of the pond.  Would suggest that the pond needs to be no lower than pH 10.5.

1 month ago
Bhaduri 1 month ago

Likely prussian blue i.e. ferriferrocyanide or  Fe4[Fe(CN)6]3·xH2O - oxidation of Fe to ferrous in your dumps, reacting w/cyanide to initially form a color free compound ferrous ferrocyanide, further oxidizing to the dark blue ferri compound; run a WAD CN & an ICP/AAS on the soln for Fe; suggest you access the following paper in Research gate for addnl clarification:


Results of voltammetry and spectrophotometry analyses revealed that upon sunlight exposure, the conversion of ferricyanide to ferrocyanide, and the reverse reaction, in the absence and in the presence of TiO2 catalyst depends strongly on pH. Thus, the pH of the solution dictates whether the redox reactions will proceed under illumination. In addition, the extent of the heterogeneous photocatalytic degradation of ferricyanide was influenced by pH. The initial concentration of ferricyanide did not affect its degradation.

Please join and login to participate and leave a comment.