Surface tensions and contact angles due to lignin sulphonates in the system: Liquid sulphur, aqueous zinc sulphate and zinc sulphide

Owusu, George; Peters, E.; Dreisinger, David

doi:10.1002/cjce.5450700125

Cited by 18 publications

(4 citation statements)

References 5 publications

(6 reference statements)

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“…With the lignin added, the silver extraction percentage increases to 94.5 pct, but the zinc extraction percentage remains constant at about 6 pct. These results are inconsistent with those of Owusu, [21,28] who showed that the extraction percentage of zinc in pressure leaching increased from 50 pct to 93.6 pct (0.1 g/L lignin) or 99.8 pct (0.1 g/L orthophenylene diamine). The reason for the high silver extraction percentage in our experiments without adding surfactants is that some organic amines were used during the flotation process and ultimately remained in the silver flotation concentrates.…”

Section: F Effect Of Lignin Additioncontrasting

confidence: 78%

Oxidative Pressure Leaching of Silver from Flotation Concentrates with Ammonium Thiocyanate Solution

Yang

Liu

et al. 2009

Metall Mater Trans B

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The thermodynamics and technologies of the selective pressure leaching of silver from flotation concentrates were investigated in an ammonium thiocyanate medium. Thermodynamic analyses, which include silver solubility in NH 4 SCN solution and Eh-pH diagrams of the Me-MeS-NH 4 SCN-H 2 O system at 25°C, were discussed. The effects of several factors, such as temperature, leaching time, oxidant, pH value, flotation concentrates concentration, surfactant concentration, and so on, on the extraction percentages of silver and zinc were investigated. The following optimal leaching conditions were obtained: NH 4 SCN concentration 1.5 M, lignin concentration 0.5 g/L, Fe 3+ concentration 2 g/L, flotation concentrates addition 200 g/L, and oxygen pressure 1.2 MPa at 130°C for 3 hours. Under these optimum conditions, the average extraction percentage of silver exceeded 94 pct, whereas the average extraction percentage of zinc was less than 3 pct. Only 7 pct of ammonium thiocyanate was consumed after 4 cycles, which indicated that ammonium thiocyanate hardly was oxidized under these oxidative pressure leaching conditions.

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Section: F Effect Of Lignin Additioncontrasting

confidence: 78%

Oxidative Pressure Leaching of Silver from Flotation Concentrates with Ammonium Thiocyanate Solution

Yang

Liu

et al. 2009

Metall Mater Trans B

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“…Establishing the cause of the insufficient effectiveness of LS and the development of new highly effective surfactants and formulations of multicomponent surfactant compositions are constrained by the lack of data on interfacial phenomena, namely, the processes of adsorption, wetting, and dispersion of minerals with the participation of surfactants under conditions simulating the autoclave leaching of ores. It should be emphasized that targeted studies of surface phenomena at the mineral–elemental sulfur–surfactant boundary, carried out by Naboychenko, Goryachkin, Shneyerson, Owusu, Dreisinger, and Naftal ,− have certainly significantly advanced our understanding of the mechanisms of implementation of the surface effect of surfactants. Meanwhile, a number of issues remain which require practical verification and theoretical substantiation, in particular, the effect of the ionic composition of the liquid phase on the processes of wetting and adsorption of minerals and elemental sulfur has not been studied.…”

Section: Introductionmentioning

confidence: 99%

Surface Phenomena with the Participation of Sulfite Lignin under Pressure Leaching of Sulfide Materials

Lugovitskaya

Rogozhnikov

2023

Langmuir

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Searching for surfactants which can eliminate the occluding effect of molten elemental sulfur formed in the process of leaching sulfide ores under pressure (autoclave leaching) is relevant. However, the choice and use of surfactants are complicated by the harsh conditions of the autoclave process, as well as the insufficient knowledge of surface phenomena in their presence. This paper presents a comprehensive study of interfacial phenomena (adsorption, wetting, and dispersion) involving surfactants (using lignosulfonates as an example) and zinc sulfide/concentrate/elemental sulfur under conditions simulating sulfuric acid leaching of ores under pressure. The influence of concentration (C LS 0.1−1.28 g/dm 3 ), features of the molecular weight (M̅ w , 9.250−46.300 Da) composition of lignosulfates, temperature (10−80 °C), addition of sulfuric acid (CH 2 SO 4 0.2−10.0 g/dm 3 ), and properties of solid-phase objects (surface charge, specific surface area, presence and diameter of pores) on surface phenomena at the liquid−gas and liquid−solid interfaces was revealed. It was found that with an increase in molecular weight and a decrease in the degree of sulfonation, the surface activity of lignosulfonates at the liquid−gas interface, as well as their wetting and dispersing activity with respect to zinc sulfide/concentrate increases. It has been found that an increase in temperature contributes to the compaction of the macromolecule of lignosulfonates, as a result of which their adsorption at the liquid−gas and liquid−solid interface in neutral media rises. It has been shown that the introduction of sulfuric acid into aqueous solutions increases the wetting, adsorption, and dispersing activity of lignosulfonates with respect to zinc sulfide. The latter is accompanied by a decrease in the contact angle θ (by 10 and 40°) and an increase in both the specific number of zinc sulfide particles (not less than 1.3−1.8 times) and the content of fractions with a size of −3.5 μm. It has been established that the functional effect of lignosulfonates under conditions simulating sulfuric acid autoclave leaching of ores is implemented through the adsorption−wedging mechanism.

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“…За прошедшие десятилетия был накоплен большой опыт реализации АОВ цинковых концентратов [3,6], получены данные о кинетике процесса, влиянии состава концентратов [7][8][9][10][11][12][13][14][15][16][17][18][19] и добавок на эффективность выщелачивания [20,21].…”

Section: Introductionunclassified

Thermodynamic analysis of zinc sulfide dissolution stoichiometry in sulfuric acid solution with oxygen

Solovyeva

Kolmachikhina

Mamyachenkov

2020

Izv.VUZ. Tsvet. Met.

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A thermodynamic study of zinc sulfide high temperature oxidation leaching was conducted. Several processes can run simultaneously while metal sulfides are dissolved by oxidants in acidic solutions. Thermodynamic calculations were made using stoichiometric equations with equal oxidant consumption in order to identify the proportion of potential reactions. Moreover, stoichiometric coefficients were chosen in such a way as to reagents could exchange 1 mole of electric charge. This approach ensures a comparison of different oxidants in terms of their effectiveness in sulfides leaching. Thermodynamic analysis results obtained agree with experimental data confirming that oxidizing reactions with the formation of sulfur and sulfate ions prevail in zinc sulfide dissolution in sulfuric acid solutions under the oxygen effect. The effect of oxygen consumption and initial sulfuric acid concentration on the proportion of these reactions and equilibrium concentration of zinc cations in the solution was studied. Thermodynamic analysis showed that if the acid concentration is insufficient and limits the maximum progress of zinc sulfide oxidation with sulfur formation, oxygen is also consumed for the oxidation reaction with the formation of sulfate ions spending oxygen less effective due to 4 times less zinc cations passing to the solution. Thermodynamic calculations made it possible to find out the optimal proportions of oxygen consumption and initial sulfuric acid concentration to achieve the maximum zinc equilibrium concentration in the solution with more effective oxidant consumption without any labor-intensive experiments. The equilibrium concentration of zinc cations in the solution is in direct proportion to the initial acid concentration, and zinc cation formation is in direct proportion to oxygen consumption at the optimal acid concentration.

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Surface tensions and contact angles due to lignin sulphonates in the system: Liquid sulphur, aqueous zinc sulphate and zinc sulphide

Cited by 18 publications

References 5 publications

Oxidative Pressure Leaching of Silver from Flotation Concentrates with Ammonium Thiocyanate Solution

Oxidative Pressure Leaching of Silver from Flotation Concentrates with Ammonium Thiocyanate Solution

Surface Phenomena with the Participation of Sulfite Lignin under Pressure Leaching of Sulfide Materials

Thermodynamic analysis of zinc sulfide dissolution stoichiometry in sulfuric acid solution with oxygen

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