The generation of cyanide-containing tailings is increasing, so the search for methodologies and microorganisms to counteract the negative action to the detriment of the environment is incessant. The present study was carried out with strains of Pseudomonas pseudoalcaligenes isolated from effluents of the gold ore cyanidation process. First, tolerance tests were performed in solutions with 250 ppm sodium cyanide at different pH values, using an initial population of 4.00E+07 CFU/mL and agitated for a period of 54 hours; degradation up to 39.2% free cyanide (CN-) was observed at a pH of 9.8. Then, in the CN- degradation for 144 hours, in media consisting of cyanidation process effluent solution at pH 10.5, with an initial bacterial population of 9.94E+08 CFU/mL and at concentrations of 80 to 700 ppm of CN-, reductions of 55.89 to 84.79 % of cyanide were obtained, expressed with the equati...

The worldwide demand for silver is increasing due to the technological development in different areas, especially for the requirements in the production of renewable energies; therefore, for the treatment of refractory minerals by conventional processes, it is necessary to study mechanisms to identify the viability of their processing and the feasibility of their recovery, ensuring profitability. Gold and silver present in the matrix of sulfide-based ores are not affordably recovered by the conventional method involving leaching in sodium cyanide solution. Therefore, it must be subjected to oxidation pretreatment or conversion of the sulfides to simple compounds that allow recovery of the precious metals. The methods of oxidation of minerals considered refractory are carried out by hydro and pyrometallurgical methods, seeking the dissolution of sulfur, iron, arsenic and other elements pr...