RU-2024133243-A - METHOD FOR REGENERATION OF FREE CYANIDE AND PRECIPITATION OF COPPER USING SULFATE-REDUCING BACTERIA

Inventors

• Гринько Семен Дмитриевич
• Файберг Анна Александровна
• Епифоров Александр Владимирович
• Гудков Сергей Станиславович

Assignees

• Акционерное общество "Иркутский научно-исследовательский институт благородных и редких металлов и алмазов" (АО "Иргиредмет")

Dates

Publication Date

20260505

Application Date

20241105

Claims (3)

1. 1. A method for regenerating free cyanide and precipitating copper using sulfate-reducing bacteria, comprising treating a recycled process solution after gold extraction containing copper cyanide complexes with biogenic hydrogen sulfide, acidifying the hydrogen sulfide-treated solution with sulfuric acid to a pH of 3.0-5.0 to form insoluble copper sulfide and hydrogen cyanide, separating the resulting copper sulfide precipitate from the solution, alkalizing the deionized solution with sodium hydroxide to a pH of 10.0-11.5 to regenerate free sodium cyanide, reusing the regenerated cyanide solution for gold extraction, characterized in that the treatment of the recycled process solution after gold extraction containing copper cyanide complexes is carried out with biogenic hydrogen sulfide, and the production of biogenic hydrogen sulfide is combined and carried out in a single reactor, and to produce biogenic hydrogen sulfide, the following is added to the recycled process solution containing copper cyanide complexes: sulfate-reducing bacteria Desul f onatronum zhilinae, Desul f onatronum cooperatium, Desul f onatronobacter acetoxidans, the method is carried out at a temperature of 20 to 40°C, pH 8.5-10.5, sulfate ions are used as an electron acceptor, sodium lactate or ethyl alcohol as an electron donor, while the hydraulic retention time of the liquid phase is not less than 3 days and not more than 10 days.
2. 2. The method according to paragraph 1, characterized in that the source of sulfate ion in the recycled solution is sulfuric acid supplied to the solution at the acidification stage during the precipitation of copper sulfide.
3. 3. The method according to paragraph 1, characterized in that when the pH value increases to >10.5, sulfuric acid can be fed into the bioreactor, and when the pH decreases to <8.5, sodium hydroxide can be fed into the bioreactor.