The use of bromine as a lixiviant for leaching gold from ores is reported in the literature as far back as 1882.2 To overcome the problems of handling and use (high vapor pressure and corro­ sion) inherent with liquid bromine, a liquid bromine carrier of considerably lower vapor pressure than liquid bromine has been developed.

The best conditions for leaching of Pd and Au in NaClO-HCl-H2O2 leaching system were determined to be 5M HCl, 1V% H2O2, 10V% NaClO at 336K for 3h with a solid/liquid ratio of 1/10. of Pd and ...

The leaching experiments with iodine, bromine and aqua regia showed the fastest and continuous gold dissolution over time. A significant influence of temperature on gold leaching was observed in ...

Under the conditions of collective leaching of silver, gold and palladium with a slightly acidic (pH = 1.98) bromine-bromide solution, with a content of 100.8 g · dm-3 of bromide ions, it is ...

The recovery of gold from oxide ores with bromine was comparable to that achievable with cyanide and bromine consumption was reasonable when leaching was conducted at a near neutral pH of ~6.

In bromine medium, the gold is oxidized by bromine and stabilized as the gold bromide complex, as represented in Equations (1)–(3). Studies of the reduction potential (Eh) vs. pH diagram for the feasibility of gold in halide medium revealed that leaching of gold is possible [ 13, 15, 17 ].

The group of chemicals known as halides is composed of the elements fluorine, chlorine, bromine, and iodine. We will ignore fluorine because it does not dissolve gold. The elements listed above are in order of their molecular weights, density, cost, and reactivity. Chlorine is the lightest, cheapest and least reactive while iodine is heaviest ...

Nearly all gold-mining companies use this toxic gold leaching process to sequester the precious metal. ... In each wire, the gold ion is held together in the middle of four bromine atoms, while the potassium ion is surrounded by six water molecules; these ions are sandwiched in an alternating fashion by alpha-cyclodextrin rings. ...

The leaching results indicated that the cobalt modification increased gold dissolution, and the gold leaching percentage was increased by 40% within 8 h. the tendency of gold to dissolve more ...

Aqua regia and iodine/iodide leaching systems were the most successful reagents, yielding of gold while showing very fast leaching rates. A comparison between the two successful reagents was carried out, with the results favoring iodine leaching due to its high selectivity for precious metals and reduced environmental impact.

Fig. 2 shows that the highest degrees of Au leaching, i.e., 92.2% and 87.8% for the CAS and pyrite samples, respectively, were achieved when the CAS and pyrite samples were bioleached in the PW and LM growth medium, respectively (Daibova et al., 2019).The low gold recovery for the pyrite sample in the PW growth media (Fig. 2) was …

Experimental Results. As can be seen from Fig. 2, leaching rate increased with reagent concentration.The increase of the concentration of NaBr contributes to the leaching reaction of gold. When the concentration of NaBr is 0.1942 mol/L, the leaching rate can reach 64% after 4-h stirring, while the leaching rate was lower with insufficient …

Results showed that significantly higher gold recovery can be achieved with bromine than with cyanide when leaching gold encapsulated in sulphides, but bromine consumption was high owing...

leaching, for the treatment of gold sulfide minerals and refractory gold ores. Two other important halide leaching reagents are bromine and iodine. Generally, the major advantage of halide reagents in the gold leaching is their powerful oxidizing ability, leading to a high dissolution rate compared to alkaline cyanide leaching.

Leaching parameters have been optimized with the help of the second-order empirical equations and analysis of variance (ANOVA) for maximum gold dissolution. …

Iodine gold leaching can be a promising alternative to cyanide leaching because of its low volatility and ... Bromine leaching as an alternative method for gold dissolution. Minerals Engineering. 2018; 118:16-23. DOI: 10.1016/j.mineng.2017.12.019; 41. Meng Q, Li G, Kang H, Yan X, Wang H, Xu D. A study of the electrodeposition of Gold …

Arrhenius Plot for the gold-bromine leaching system. 3. Supplementary Materials C: Kinetic Model Derivations 3.1. Shrinking Model for Spherical Particles In a quasi-steady state with a constant atmospheric pressure, with respect to the fluid film diffusion controlling, the reaction rate of Au can be described as follows: − 1 × 𝑑𝑁𝐴

The presence of 20 per cent, of silver in the gold does not make more than 1 per cent, difference in the extraction in the first four tests with 8.97, 5.98, 4.48 and 2.99 g. of bromine; the fall begins with 2.6 g. of bromine which dissolve 77.6 per cent, of gold, while in the absence of silver the same amount of bromine gives an extraction of ...

We performed experimental tests in order to assess the feasibility of bromine produced in-situ, in the leaching reactor, to dissolve gold using ore samples from the unexploited …

Materials. 2020. TLDR. The obtained results demonstrate that all studied metals could be successfully leached using brominated solutions, providing a viable alternative for the selective and efficient recovery of the base metals from WPCBs through a multi-step hydrometallurgical processing route.

leaching, for the treatment of gold sulfide minerals and refractory gold ores. Two other important halide leaching reagents are bromine and iodine. Generally, the major advantage of halide ...

EVALUATION OF STABILIZED BROMINE TECHNOLO GY FOR GOLD LEACHING. By. 1 Mike Dry, 2 Joe O'Day, 2 Mani Marimaran, 3 Mariam Mel ashvili and 3 Chris Flem ing. 1 Arithmetek Inc., Canada.

Silver, gold and palladium leaching from electronic scrap using bromine- bromide solution. This study investigated the thermodynamics and kinetics of gold and …

The result shows that dissolution rate of gold foil is far away from that in NBS. The gold foil begins to dissolve at day 3 and only partly dissolved at day 10. What's more, the yield of gold leaching from ore by bromine solution is 53.5% lower than that of 86.24% by NBS. That is to say, Br 2 may not be the only factor to make gold dissolved.

Barbosa-Filho O. and Monhemius AJ.(1989) Thermochemistry of thyocyanate systems for leaching gold and silver ores, in Precious Metals′89 (eds. M.C. Jha and others), TMS-AIME, 307. Google Scholar . Bray W.C. and Livingstone R.S.(1923) The catalytic decomposition of hydrogen peroxide in a bromine-bromide solution and a study of the …

A gold extraction rate of 99% can be achieve d at optimal conditions which are a low pH le vel of 1 - 2 as well. as the presence of oxyge n and iron as an oxidant. Other advantages to c yanide are ...

The leaching of silver, gold, and palladium from printed circuit boards in the bromine - bromide system after preliminary removal of the associated metals and copper has been investigated.

The metals that are more active than gold may reduce gold from gold-bromine complex ions to gold metal, which may further change the leaching mechanism. There is also a possibility of a mechanism ...

The gold leaching reaction by thiosulfate without additives is shown in Eq. (4). (4) 4Au + 8S 2 O 3 2-+ O 2 + 2H 2 O → 4Au ... From an environmental perspective, in chlorine and bromine leaching, toxic vapors such as chlorine, bromine, hydrogen chloride, and hydrogen bromide may be generated, which are required to be controlled and …

The leaching experiments with iodine, bromine and aqua regia showed the fastest and continuous gold dissolution over time. A significant influence of temperature on gold leaching was observed in all experiments. Iodine is capable to extract gold a very fast (average dissolution rate of 65.679 mg·h −1 ·cm −2 at 25 °C).