References of "Frenay, Jean"
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See detailSeparation of Copper and Zinc by Solvent Extraction During Reprocessing of Flotation Tailings
Kitobo, Willy; Gaydardzhiev, Stoyan ULg; Frenay, Jean ULg et al

in Separation Science & Technology (2010), 45(4), 1-6

Results from solvent extraction of copper and zinc from pregnant solutions after bioleaching of re-floated tailings from the Kipushi concentrator in DR of Congo are presented. LIX984N has been used as ... [more ▼]

Results from solvent extraction of copper and zinc from pregnant solutions after bioleaching of re-floated tailings from the Kipushi concentrator in DR of Congo are presented. LIX984N has been used as extractant for copper, while D2EHPA as such for zinc, following prior removal of the ferric iron via precipitation. The McCabe-Thiele diagrams constructed for Cu and Zn extraction have theoretically suggested the need for two stages for copper and one for zinc. Stripping these metals to aqueous phase by sulphuric acid has yielded rich electrolytes with 48.5 g/L copper and 85.5 g/L zinc. Thus, copper and zinc could be further recovered from the stripped solutions by electrolysis. [less ▲]

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See detailBacterial leaching of complex sulphides from mine tailings altered by acid drainage
Kitobo, Willy; Gaydardzhiev, Stoyan ULg; Frenay, Jean ULg et al

in Dominic, Esteban (Ed.) Bacterial leaching of complex sulphides from mine tailings altered by acid drainage (2009, May)

An experimental study aimed at re-flotation of laid down tailings from Kipushi (DRC) to bring sulphide concentrate suitable for further processing by hydrometallurgical means has been realized. The ... [more ▼]

An experimental study aimed at re-flotation of laid down tailings from Kipushi (DRC) to bring sulphide concentrate suitable for further processing by hydrometallurgical means has been realized. The results from a bioleaching route chosen to accomplish the later task by use of moderate thermophilic and mesophilic microorganisms are reported. It has been found that due to the complexity of the treated material, the leaching pattern of the two principal metals of interest, copper and zinc vary. Whilst the copper bearing minerals have been leached relatively fast by direct mechanism, the leaching kinetics for the zinc minerals has been moderate involving predominantly an indirect mechanism. The effects of pH and temperature variations and ferrous ions addition upon the extent of copper and zinc dissolution have been examined. The presence of ferrous ions has been found beneficial for the leaching of sphalerite, however the concomitant formation of jarosite precipitates has led to copper leaching hindrance. Similarly, the rapid zinc solubilisation has been counterbalanced by decrease in rate of copper dissolution. [less ▲]

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See detailSampling of Fine Shredder Residues (FSR) and Characterization Oriented to Physical Separations
Bareel, Pierre-François; Bastin, David ULg; Bodson, Claude et al

in Proceedings of the Sohn International Symposium on Advanced Processing of Metals and Materials: Principles, Technologies and Industrial Practice (2006)

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See detailThe roles of complexing agents in the sulfidisation and xanthate flotation of cobalt oxy hydroxides of copper-cobalt oxides ores from the Congolese Copperbelt
Bastin, David ULg; Frenay, Jean ULg; Vermaut, Norbert

Conference (2006)

Complex mineralogy combined with a variable chemistry lead to various flotation responses of cobalt oxy-hydroxides present in oxidised and mixed copper-cobalt stratiform deposits of the Central African ... [more ▼]

Complex mineralogy combined with a variable chemistry lead to various flotation responses of cobalt oxy-hydroxides present in oxidised and mixed copper-cobalt stratiform deposits of the Central African Copperbelt. Optimum metallurgical results require very high dosages of reagents and the management of such high chemicals concentrations in the pulp at the plant scale is delicate. The transition period between high reducing conditions during the sulfidisation step and a more oxidising environment prevailing during collector adsorption is particularly critical. This paper demonstrates how the use of copper and cobalt complexing agents can significantly improve the process control and metallurgical performance. The different modes of action of these reagents are presented and mechanisms for the various reactions proposed. Plant results following the introduction of ammonium sulfate at the New Concentrator of Kipushi are discussed. [less ▲]

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See detailPotential valorization for the finest particles of Automotive Shredder Residues
Bareel, Pierre-François; Mordant, Bruno; Bastin, David ULg et al

in Acta Metallurgica Slovaca (2004), 2

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See detailPotential valorization for the finest particles of Automotive Shredder Residue (ASR) as filler in bituminous concrete
Bareel, Pierre-Francois; Courard, Luc ULg; Bastin, David ULg et al

in Proceedings of REWAS'04 - Global Symposium on Recycling, Waste Treatment and Clean Technology (2004)

Car manufacturers are faced with increasingly severe European regulations concerning End of Live Vehicles (ELV) recycling. Issues for the coarse fractions of Automotive Shredder Residue (ASR) are now ... [more ▼]

Car manufacturers are faced with increasingly severe European regulations concerning End of Live Vehicles (ELV) recycling. Issues for the coarse fractions of Automotive Shredder Residue (ASR) are now quite largely studied. However, the European objectives could only be achieved by considering the processing and valorization of the fine ASR fraction (< 2mm) which usually represents 5 to 10 wt.% of shredded ELV. A laboratory study was carried out on the fine ASR fraction. By combining granulometric, gravimetric and magnetic separations, four valorizable fractions were identified. This paper presents the valorization of the finest fraction (< 250 μm) as filler in bituminous concrete. Physical and chemical properties were first determined. Bituminous concrete samples were then prepared with different substitution levels of calcareous filler by fine ASR. Marshall tests (mechanical properties) and leaching tests were performed without compromising results. [less ▲]

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See detailPotential valorization of the fine light fraction of automotive shredder residues (ASR)
Bareel, Pierre-François; Bastin, David ULg; Frenay, Jean ULg

in Proceedings of the International Symposium of Metals and Energy Recovery (2003)

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See detailAmmonium sulphate as promoting agent of the sulphidization process of oxidized Cu-Co ores from the Luiswishi deposit (RDC)
Bastin, David ULg; Frenay, Jean ULg; Philippart, Pierre

Poster (2003)

The Luiswishi deposit belongs to the Cu-Co deposits of the Southern Group of the Katangian Copper Belt and is operated by a joint venture between EGMF (Entreprises Générales Malta Forrest) and Gecamines ... [more ▼]

The Luiswishi deposit belongs to the Cu-Co deposits of the Southern Group of the Katangian Copper Belt and is operated by a joint venture between EGMF (Entreprises Générales Malta Forrest) and Gecamines (Générale des Carrières et des Mines). The Cu-Co ore is beneficiated by the sulphidization process at the NCK (New Concentrator of Kipushi) at Kipushi. Sulphidization followed by flotation with sulphydryl collectors is a common practice for the treatment of oxidized base metals ores. This process is complex and its application at the industrial scale is quite sensitive. In Central Africa it is also a cost intensive treatment as the sulphidizing agent has to be imported. In order to improve the metallurgical performances and to optimise the economics of the process, a laboratory research program was carried out by the Laboratory of Metallurgy and Mineral Processing (MTM) of the University of Liège in close collaboration with EGMF and Gecamines. This program included the study of various flotation reagents as dispersing, depressing and activating agents. This paper presents the results obtained with the use of ammonium sulphate as activator of the sulphidized xanthate flotation. Although ammonium sulphate has been mentioned in the literature as a promoting agent of the sulphidized xanthate flotation of malachite, its effects on the flotation of cobalt oxides was not known. The testworks were carried out on various oxidized siliceous ore types from the Luiswishi deposit. A 1.7 l Agitair laboratory flotation cell was used. NaHS and potassium amylxanthate were respectively choosen as sulphidizer and collector. A mixture of gasoil and tall oil (90/10) was used as secondary collector. A multistage sulphidization was realised. Values of pH were followed during the different tests and an ion selective electrode Ag/Ag2S was used to control the Es potentiel evolution during the stepwise addition of the sulphidizer. The addition of ammonium suphate [(NH4)2SO4] simultaneously with NaHS led to the following results: -A marked improvement of the sulfidization kinetics leading to shorter conditioning times and limiting the number of sulphidizing stages required to reach maximum recoveries. -The inhibition of the depressive effect on Cu and Co flotation of an excess of hydrosulphide ions in the pulp. -An improvement of the selectivity of the flotation combined with higher cobalt recoveries. The promoting effect is indeed more effective for cobalt than for copper and cobalt recoveries were improved by 4 to 8 %. -A significant decrease of the sulfidizer consumption. These laboratory results were implemented at an industrial scale at the NCK at Kipushi. In close accordance with the laboratory results the sulphidization kinetics were improved and the cobalt recoveries rose by 7 % while maintaining the previous Cu and Co grades of the concentrate. Ammonium sulphate being a low cost and common reagent (it is easily found in the fertiliser industry or as a byproduct of the coke industry), its use significantly improved the economics of the flotation of Cu-Co oxides ores from the Luiswishi deposit. [less ▲]

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See detailMetals in aqueous solutions in: biosorption of heavy metals
Darimont, Anne ULg; Frenay, Jean ULg

in Metals in aqueous solutions in: biosorption of heavy metals (1989)

Detailed reference viewed: 12 (1 ULg)