Investigation into the use of an anion exchange membrane for gold adsorption

Electrolytic manganese dioxide (EMD): a perspective on worldwide production, reserves and its role in electrochemistry

“…Mauthoor et al 113 varied the bath temperature between 90 to 108 C. They report 9% higher discharge capacity of EMD when deposited from a bath having 95-108 C than that of 90-95 C. However on increasing the temperature beyond 105 C, the discharge capacity decreased slightly. Mauthoor et al 113 varied the bath temperature between 90 to 108 C. They report 9% higher discharge capacity of EMD when deposited from a bath having 95-108 C than that of 90-95 C. However on increasing the temperature beyond 105 C, the discharge capacity decreased slightly.…”

“…The physical as well as electrochemical properties of EMD can be strongly inuenced by the bath temperature from which it gets deposited. Mauthoor et al 113 varied the bath temperature between 90 to 108 C. They report 9% higher discharge capacity of EMD when deposited from a bath having 95-108 C than that of 90-95 C. However on increasing the temperature beyond 105 C, the discharge capacity decreased slightly. Ghaemi et al 114 in his doctoral work has found that EMD produced at a low bath temperature of 60 C showed inferior capacity than the EMDs produced at a bath temperature of 96-98 C. Later, investigation was also carried out by Ghaemi et al 115 on a wide range of temperature from 60-120 C. The author found that high temperature of the bath leads to the formation of EMDs with high crystalline grade and consequently more structural hardness with better electrochemical performance.…”

Adsorption of a gold‐iodide complex (AuI2−) onto cellulose acetate‐polyaniline membranes: Equilibrium experiments

“…The results in Figure 1 indicate that the adsorption kinetics is faster than those reported for commercial resins and membranes of anion exchange, and activated carbon using cyanide as leaching solution for Au, which attained conditions equilibrium in the range of 1200-2500 min. 13 Membranes coated with PANI presented adsorption kinetics faster and with higher gold recovery than those obtained with uncoated membranes. These results are attributed to the presence of PANI.…”

“…The most common method of extraction is the carbon‐in‐pulp process. The gold adsorption occurs from a slurry containing fine ground rock particles and possibly a number of other metals in solution and organics, which may poison the carbon 13. Recently, there has been interest in using ion‐exchange resins instead of activated carbon.…”

“…In the case of granular adsorbents, the flow of mine slurry through a packed bed is not practical because the slurry blocks the bed. If ion‐exchange membranes could be used for treating gold slurries, it would be possible to simulate a packed bed by passing the slurry through a column in which a number of parallel sheets of membrane are placed 13. Diniz et al15 reported matrices containing polyaniline displaying ion‐exchange properties, the matrices being selective to anions based upon their radii, with a cut‐off value around 240 pm.…”