Electrochemical dissolution behavior of gold and its main coexistent sulfide minerals in acid thiocyanate solutions

Una Comparación de Reactivos Alternos al Cianuro como Lixiviantes del Oro: Una revisión

“…Figura 6. Mapa bibliográfico de la lixiviación del oro con tiocianato El diagrama anterior muestra que las investigaciones actuales sobre la lixiviación de oro utilizando tiocianato están enfocadas en la lixiviación de minerales de diferente composición (Azizitorghabeh et al, 2021;Le et al, 2022), además de, una vez realizada la lixiviación, los métodos de recuperación más efectivos para extraer el oro desde las soluciones que lo contienen, siendo los más prometedores la extracción por solventes, la cementación y la adsorción con carbón activado y membranas de intercambio iónico (Azizitorghabeh et al, 2021).…”

Study on the Galvanic Interaction of Gold and Main Associated Minerals Based on Density Functional Theory

“…And, the charge of increases as the distance between the two layers of crystals increases, indicating tha gradually loses electrons as the distance increases. The study of Tafel curve by L [23] showed that the corrosion potential of pyrite was lower than that of gold, and In order to achieve a better matching ratio between the mineral and gold surface and better combination, a larger mineral and gold supercell surface was used. In Figure 1 In order to study the galvanic interaction between pyrite, arsenopyrite, and chalcocite and gold, we adjusted and changed the distance between the mineral and the surface of the gold stratiform crystal and established a galvanic interaction model with different distances (3 Å, 5 Å, 8 Å) between the mineral and the surface of the gold stratiform crystal, as shown in Figures 1-3.…”

“…And, the charge of pyrite increases as the distance between the two layers of crystals increases, indicating that pyrite gradually loses electrons as the distance increases. The study of Tafel curve by Le et al [23] showed that the corrosion potential of pyrite was lower than that of gold, and pyrite was oxidized as an anode to lose electrons. When the distance between the charges of gold is 8 Å, the charge is the most negative and the number of electrons obtained by gold is the highest.…”

Evaluation of gold adsorption on activated carbon from real cyanide and thiourea leachate solutions

“…Thiourea forms cationic complex with gold and silver, by the action of formamidine di-sulfide, which is considered as a very effective oxidant for metal dissolution, easier to handle, possesses higher selectivity towards gold and faster kinetics of the initial leaching reactions with a suitable oxidant, such as ferric sulphate, which has proven to be the most effective one [ [20] , [21] , [22] , [23] ]. However, the literature reports [ [24] , [25] , [26] , [27] ] disadvantages of thiourea, such as its easy degradation and stabilization at the ore surface due to the leach residue. Thiourea dissolves the gold under acidic conditions, which allows the use of ferric sulphate as an oxidizing agent, forming a cationic complex [ 6 , 28 , 29 ], equation (3) [ 30 ]: Au + 2SC(NH 2 ) 2 ⇄ Au(SC(NH 2 ) 2 ) 2+ + e − …”