Nitric acid loosening of rebellious sulphide concentrates containing precious metals

Rogozhnikov, D. A.; Rusalev, R.E.; Dizer, Oleg; Naboychenko, S. S.

doi:10.17580/tsm.2018.12.05

Cited by 9 publications

(6 citation statements)

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“…The results of the performed thermodynamic studies and laboratory experiments allowed us to establish the ranges of the leaching process parameters: temperature of 70-100 • C, acid concentration of 10-60% at L:S 20:1. Lower values of L:S are also possible; however, it was previously found that at low values of L:S and a high acid concentration, the reaction is very intense, which impedes temperature control, while the degree of extraction in this case changes slightly [33].…”

Section: Chemistry Of Hno 3 Leachingmentioning

confidence: 93%

“…One of the possible methods of hydrometallurgical processing of refractory sulfide raw materials is the use of HNO 3 to oxidize the materials without the use of high pressure or fine grinding [28][29][30][31], as nitric acid is one of the most effective oxidizing and leaching agents [32,33].…”

Section: Of 15mentioning

confidence: 99%

“…Previously, we had studied the thermodynamic characteristics for the above interactions [33]. The study found that the oxidation potential of the system is to be maintained at 0.6 V or higher for reactions with transfer of iron and arsenic into the solution.…”

Section: Chemistry Of Hno3 Leachingmentioning

confidence: 99%

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Leaching Kinetics of Sulfides from Refractory Gold Concentrates by Nitric Acid

Rogozhnikov

Shoppert

Dizer

et al. 2019

Metals

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The processing of refractory gold-containing concentrates by hydrometallurgical methods is becoming increasingly important due to the depletion of rich and easily extracted mineral resources, as well as due to the need to reduce harmful emissions from metallurgy, especially given the high content of arsenic in the ores. This paper describes the investigation of the kinetics of HNO3 leaching of sulfide gold-containing concentrates of the Yenisei ridge (Yakutia, Russia). The effect of temperature (70–85 °C), the initial concentration of HNO3 (10–40%) and the content of sulfur in the concentrate (8.22–22.44%) on the iron recovery into the solution was studied. It has been shown that increasing the content of S in the concentrate from 8.22 to 22.44% leads to an average of 45% increase in the iron recovery across the entire range temperatures and concentrations of HNO3 per one hour of leaching. The leaching kinetics of the studied types of concentrates correlates well with the new shrinking core model, which indicates that the reaction is regulated by interfacial diffusion and diffusion through the product layer. Elemental S is found on the surface of the solid leach residue, as confirmed by XRD and SEM/EDS analysis. The apparent activation energy is 60.276 kJ/mol. The semi-empirical expression describing the reaction rate under the studied conditions can be written as follows: 1/3ln(1 − X) + [(1 − X)−1/3 − 1] = 87.811(HNO3)0.837(S)2.948e−60276/RT·t.

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Section: Chemistry Of Hno 3 Leachingmentioning

confidence: 93%

Section: Of 15mentioning

confidence: 99%

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Leaching Kinetics of Sulfides from Refractory Gold Concentrates by Nitric Acid

Rogozhnikov

Shoppert

Dizer

et al. 2019

Metals

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“…The study used solutions obtained after nitric acid leaching of gold-arsenic sulphide concentrates of the Uderey deposit (Krasnoyarsk Region), containing %: 21.6 Fe, 12.2 As, 20.0 S, 3.5 Al and 30 g/t Au [34,35]. The method and conditions of leaching were previously described in detail [34].…”

Section: Materials and Reagentsmentioning

confidence: 99%

Deposition of Arsenic from Nitric Acid Leaching Solutions of Gold–Arsenic Sulphide Concentrates

Karimov

Rogozhnikov

Dizer

et al. 2021

Metals

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At present, the processing of refractory gold–arsenic sulphide concentrates is becoming more relevant due to the depletion of rich crude ore reserves. In the process of the nitric acid leaching of arsenic sulphide minerals, solutions are formed containing 20–30 g/L of arsenic (III). Since market demand for arsenic compounds is limited, such solutions are traditionally converted into poorly soluble compounds. This paper describes the investigation of precipitating arsenic sulphide from nitric acid leaching solutions of refractory sulphide raw materials of nonferrous metals containing iron (III) ions using sodium hydrosulphide with a molar ratio of NaHS/As = 2.4–2.6, which is typical for pure model solutions without oxidants. The work studied the effect of temperature, the pH of the solution and the consumption of NaHS and seed crystal on this process. The highest degree of precipitation of arsenic (III) sulphide (95–99%) from nitric acid leaching solutions containing iron (III) ions without seed occurs with a pH from 1.8 to 2.0 and a NaHS/As molar ratio of 2.8. The introduction of seed crystal significantly improves the precipitation of arsenic (III) sulphide. An increase in seed crystal consumption from 0 to 34 g/L in solution promotes an increase in the degree of transition of arsenic to sediment from 36.2 to 98.1% at pH = 1. According to SEM/EDS and XRF sediment data, from the results of experiments on the effect of As2S3 seed crystal consumption, acidity and molar ratio of NaHS/As on the precipitation of arsenic (III) sulphide and the Fetotal/Fe2+ ratio in the final solution, it can be concluded that the addition of a seed accelerates the crystallisation of arsenic (III) sulphide by increasing the number of crystallisation centres; as a result, the deposition rate of As2S3 becomes higher. Since the oxidation rate of sulphide ions to elemental sulphur by iron (III) ions does not change significantly, the molar ratio of NaHS/As can be reduced to 2.25 to obtain a precipitate having a lower amount of elemental sulphur and a high arsenic content similar to that precipitated from pure model solutions.

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“…Nitric acid has strong oxidizing properties (oxidation potential 0.957 V). It is capable of decomposing sulfide minerals, transferring copper, iron, zinc and other valuable components into solution [12][13][14]. The possibility of capturing the resulting nitrous gases with further nitric acid recovery is an advantage of this process.…”

Section: Introductionmentioning

confidence: 99%

Kinetics of nitric acid leaching of bornite and chalcopyrite

Shklyaev,

Dizer,

Lugovitskaya

et al. 2023

Chim.Tech.Acta

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The paper presents a study of the process of nitric acid dissolution of the natural minerals chalcopyrite and bornite. The influence of various parameters, including temperature, nitric acid concentration and particle sizes, on this process was examined. Based on the data obtained, the values of apparent activation energy (57.41 and 42.98 kJ/mol for chalcopyrite and bornite, respectively), empirical orders with respect to nitric acid (1.62 and 1.57 for chalcopyrite and bornite, respectively) and with respect to particle size (–1.16 and –2.53 for chalcopyrite and bornite, respectively) were calculated using the shrinking core model. Generalized kinetic equations for the dissolution process of both minerals were derived. Based on the calculations performed, it was suggested that the dissolution processes of chalcopyrite and bornite under these conditions are limited by internal diffusion.

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Nitric acid loosening of rebellious sulphide concentrates containing precious metals

Cited by 9 publications

References 0 publications

Leaching Kinetics of Sulfides from Refractory Gold Concentrates by Nitric Acid

Leaching Kinetics of Sulfides from Refractory Gold Concentrates by Nitric Acid

Deposition of Arsenic from Nitric Acid Leaching Solutions of Gold–Arsenic Sulphide Concentrates

Kinetics of nitric acid leaching of bornite and chalcopyrite

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