Improtance of fundamental study in hydrometallurgy

Majima, Hiroshi

doi:10.1007/bf02653995

Cited by 11 publications

(4 citation statements)

References 36 publications

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“…The leachate samples were aspirated into the flame alimented by air/ acetylene, burning at high temperature in order to favor atomization of metallic traces. It was observed that the Cu dissolution curve obeyed to the parabolic like behavior as in previous studies [25]. Only 16% of Cu from the mineral was recovered in the leachate after 12 hours dissolution.…”

Section: B Methodssupporting

confidence: 74%

Mineralogical Observation Made During the Kinetic Dissolution Study of Chalcopyrite Mineral in Sulphate Media under Free pH at Room Temperature

Nyembwe¹,

Fosso‐Kankeu²,

Waanders³

et al. 2018

ASETH-18,ACABES-18 &Amp; EBHSSS-18 Nov. 19-20 2018 Cape Town (South Africa)

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An attempt to determine the various phenomena at play and leaching mechanism of chalcopyrite dissolution, was conducted on a chalcopyrite concentrate. The study was performed at atmospheric conditions (room temperature) in a stirred Erlenmeyer flask with 10% solid at free pH in acidic sulphate system. It appears that, the mineral dissolution is to some extent dependent on the pH. The Cu dissolution curve was characterized at the early stage by a rapid withdrawal of both copper and solid residue. Leachate solid residue characterization results, obtained from the X-ray diffraction revealed the presence of intermediate minerals phases including bornite, covelite and chalcocite. Thermodynamic calculations predict that the dissolution of bornite and chalcocite would be spontaneous while covelite was found to be refractory. In addition to that, sulfur and gangue related mineral were identified as the dissolution reaction products.

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Section: B Methodssupporting

confidence: 74%

Mineralogical Observation Made During the Kinetic Dissolution Study of Chalcopyrite Mineral in Sulphate Media under Free pH at Room Temperature

Nyembwe¹,

Fosso‐Kankeu²,

Waanders³

et al. 2018

ASETH-18,ACABES-18 &Amp; EBHSSS-18 Nov. 19-20 2018 Cape Town (South Africa)

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“…The thermodynamic and kinetic basis for the rationalisation of the beneficial effect of chloride ions on sulfide leaching in non-sulfate systems such as strong brines has been widely reported (Peters, 1977;Winannd, 1991;Majima, 1995;Dutrizac, 1992;Muir, 2002;Flett, 2002;Muir, 1988, 2003). The HydroCopper TM process uses copper(II) chloride in strong brine (4.3 mol.dm -3 NaCl) to leach chalcopyrite concentrates at pH 1.5-2.5 and near boiling point of water (Lundstrom et al, 2005).…”

Section: Introductionmentioning

confidence: 99%

A review of chloride assisted copper sulfide leaching by oxygenated sulfuric acid and mechanistic considerations

Senanayake

2009

Hydrometallurgy

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Please cite this article as: Senanayake, G., A review of chloride assisted copper sulfide leaching by oxygenated sulfuric acid and mechanistic considerations, Hydrometallurgy (2009), doi: 10.1016/j.hydromet.2009.02.010 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. A C C E P T E D M A N U S C R I P T AbstractThe beneficial effect of chloride on sulfide leaching in sulfuric acid has been widely reported over the last 3 to 4 decades but the reasons have not been resolved. A review of recent literature shows that sulfide leaching is complex due to alternative reaction paths, competitive reactions and interim compounds formed on solid surfaces or in solutions. This study focuses on analysis of rate data for covellite leaching by oxygenated sulfuric acid in the presence of sodium chloride and comparison with the leaching data of chalcocite. The published results for initial copper leaching from covellite are analysed on the basis of a shrinking particle kinetic model to determine the apparent rate constants and reaction orders with respect to the concentrations of chloride, dissolved oxygen, and hydrogen ions. The first stage leaching of chalcocite to an intermediate CuS appears to be controlled by the mass transport of oxygen to the sulfide surface. A comparison has been made between the second stage leaching of chalcocite and the initial leaching of pure covellite to produce elemental sulfur by considering the effect of temperature on dissolved oxygen concentration and apparent rate constants. The Arrhenius plots gave comparable values for activation energy for covellite (101 kJ. mol -1 ) and second stage leaching of chalcocite (96 kJ mol -1 ). A linear correlation of stability constants was used to determine equilibrium constants for the formation of CuS 2 and Cu(OH)(Cl). The peak potentials of voltammograms of covellite are in reasonable agreement with the predicted potentials based on thermodynamics of a range of solid phases including CuS, CuS 2 , Cu(OH)Cl, and Cu 2 Cl(OH) 3 . These observations are used to propose a reaction mechanism via mixed-ligand complex species.

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“…However, the behavior respect to the percentage of extraction, is not necessarily proportional to the concentration, because the chemical characteristics of solutions (brines) are modified by elevated chloride concentrations (high ionic force) (Jansz, 1983;Majima, 1995). However, the beneficial effect is related to the stoichiometry and the driving force for the leaching reactions, especially in the cases of platinum and palladium (Eqs.…”

Section: Effect Of Chloride Concentrationmentioning

confidence: 96%

Platinum, palladium and gold leaching from magnetite ore, with concentrated chloride solutions and ozone

Torres

Lapidus

2016

Hydrometallurgy

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Improtance of fundamental study in hydrometallurgy

Cited by 11 publications

References 36 publications

Mineralogical Observation Made During the Kinetic Dissolution Study of Chalcopyrite Mineral in Sulphate Media under Free pH at Room Temperature

Mineralogical Observation Made During the Kinetic Dissolution Study of Chalcopyrite Mineral in Sulphate Media under Free pH at Room Temperature

A review of chloride assisted copper sulfide leaching by oxygenated sulfuric acid and mechanistic considerations

Platinum, palladium and gold leaching from magnetite ore, with concentrated chloride solutions and ozone

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