Treatment process for cyanide-containing tailings
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The company is currently working on a project related to cyanide-containing tailings. In some gold mines, sodium cyanide is used to extract gold from the ore pulp, and the resulting tailing pulp contains cyanides. In the past, this waste was simply discharged into tailing ponds, but now it needs to be treated. Some environmental protection companies recommend using an acidification method, which involves adding hydrochloric acid to the tailings; this reacts with the cyanides to produce hydrogen cyanide, which is highly volatile, and it can then be captured. I’m reaching out to fellow people from Sichuan – has anyone worked with a similar process? Since I’ve never designed a production process that involves reaction vessels, I don’t know where to start! I was wondering if you could send me some materials. Thank you all!
It is sodium cyanide; this substance is used to dissolve gold during its extraction. An excess amount of it is used, so the remaining ore slurry after gold extraction contains sodium cyanide. It is required that the concentration of cyanide in this tailings slurry not exceed 5 mg/L
Adding hydrochloric acid is nonsense – volatile acids present problems and make it difficult to handle the material later on. Adding sulfuric acid requires handling it in the presence of high concentrations of sodium cyanide. We have conducted experiments on acidification using sulfuric acid containing 40% sodium cyanide; since the tailings contain a significant amount of calcium, acidification isn’t a good solution. We can use the methods employed in the pharmaceutical industry instead