subject:( gold leaching)

University of Johannesburg

1. Phiri, Thulane Raymond. Roasting of sulphide concentrates and acid leaching of calcines emanating from conventional and microwave assisted roasting.

Degree: 2012, University of Johannesburg

URL: http://hdl.handle.net/10210/4849

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M.Tech.

The study presented, investigated the acid leaching behavior of calcines emanating from conventional roasting and microwave assisted roasting of sulphide ores. The aim was… (more)

Subjects/Keywords: Leaching; Gold - Metallurgy; Heat - Transmission; Microwave heating

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APA (6^th Edition):

Phiri, T. R. (2012). Roasting of sulphide concentrates and acid leaching of calcines emanating from conventional and microwave assisted roasting. (Thesis). University of Johannesburg. Retrieved from http://hdl.handle.net/10210/4849

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Phiri, Thulane Raymond. “Roasting of sulphide concentrates and acid leaching of calcines emanating from conventional and microwave assisted roasting.” 2012. Thesis, University of Johannesburg. Accessed December 10, 2019. http://hdl.handle.net/10210/4849.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Phiri, Thulane Raymond. “Roasting of sulphide concentrates and acid leaching of calcines emanating from conventional and microwave assisted roasting.” 2012. Web. 10 Dec 2019.

Vancouver:

Phiri TR. Roasting of sulphide concentrates and acid leaching of calcines emanating from conventional and microwave assisted roasting. [Internet] [Thesis]. University of Johannesburg; 2012. [cited 2019 Dec 10]. Available from: http://hdl.handle.net/10210/4849.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Phiri TR. Roasting of sulphide concentrates and acid leaching of calcines emanating from conventional and microwave assisted roasting. [Thesis]. University of Johannesburg; 2012. Available from: http://hdl.handle.net/10210/4849

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Johannesburg

2. Mukendi, David Ngalula. Application of microwaves in leaching.

Degree: 2014, University of Johannesburg

URL: http://hdl.handle.net/10210/10659

M.Tech. (Extraction Metallurgy)

Please refer to full text to view abstract

Subjects/Keywords: Leaching; Gold - Metallurgy

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APA (6^th Edition):

Mukendi, D. N. (2014). Application of microwaves in leaching. (Thesis). University of Johannesburg. Retrieved from http://hdl.handle.net/10210/10659

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Mukendi, David Ngalula. “Application of microwaves in leaching.” 2014. Thesis, University of Johannesburg. Accessed December 10, 2019. http://hdl.handle.net/10210/10659.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Mukendi, David Ngalula. “Application of microwaves in leaching.” 2014. Web. 10 Dec 2019.

Vancouver:

Mukendi DN. Application of microwaves in leaching. [Internet] [Thesis]. University of Johannesburg; 2014. [cited 2019 Dec 10]. Available from: http://hdl.handle.net/10210/10659.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Mukendi DN. Application of microwaves in leaching. [Thesis]. University of Johannesburg; 2014. Available from: http://hdl.handle.net/10210/10659

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Alberta

3. Sayer, Christina J. An electrochemical study at 25°C. of the leaching behaviour of gold and silver in inorganic and organic solutions.

Degree: MS, Department of Geology, 1986, University of Alberta

URL: https://era.library.ualberta.ca/files/3n204108q

Subjects/Keywords: Silver.; Leaching.; Gold.; Electrochemistry.

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APA (6^th Edition):

Sayer, C. J. (1986). An electrochemical study at 25°C. of the leaching behaviour of gold and silver in inorganic and organic solutions. (Masters Thesis). University of Alberta. Retrieved from https://era.library.ualberta.ca/files/3n204108q

Chicago Manual of Style (16^th Edition):

Sayer, Christina J. “An electrochemical study at 25°C. of the leaching behaviour of gold and silver in inorganic and organic solutions.” 1986. Masters Thesis, University of Alberta. Accessed December 10, 2019. https://era.library.ualberta.ca/files/3n204108q.

MLA Handbook (7^th Edition):

Sayer, Christina J. “An electrochemical study at 25°C. of the leaching behaviour of gold and silver in inorganic and organic solutions.” 1986. Web. 10 Dec 2019.

Vancouver:

Sayer CJ. An electrochemical study at 25°C. of the leaching behaviour of gold and silver in inorganic and organic solutions. [Internet] [Masters thesis]. University of Alberta; 1986. [cited 2019 Dec 10]. Available from: https://era.library.ualberta.ca/files/3n204108q.

Council of Science Editors:

Sayer CJ. An electrochemical study at 25°C. of the leaching behaviour of gold and silver in inorganic and organic solutions. [Masters Thesis]. University of Alberta; 1986. Available from: https://era.library.ualberta.ca/files/3n204108q

Curtin University of Technology

4. Oraby, Elsayed A. Gold leaching in thiosulfate solutions and its environmental effects compared with cyanide .

Degree: 2009, Curtin University of Technology

URL: http://hdl.handle.net/20.500.11937/148

► Nowadays, keeping mining and the environment sustainable is a major concern all over the world. Using toxic chemicals such as cyanide and mercury in the… (more)

Subjects/Keywords: thiosulfate solutions; mining; gold leaching; cyanide; environmental effects; mercury

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APA (6^th Edition):

Oraby, E. A. (2009). Gold leaching in thiosulfate solutions and its environmental effects compared with cyanide . (Thesis). Curtin University of Technology. Retrieved from http://hdl.handle.net/20.500.11937/148

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Oraby, Elsayed A. “Gold leaching in thiosulfate solutions and its environmental effects compared with cyanide .” 2009. Thesis, Curtin University of Technology. Accessed December 10, 2019. http://hdl.handle.net/20.500.11937/148.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Oraby, Elsayed A. “Gold leaching in thiosulfate solutions and its environmental effects compared with cyanide .” 2009. Web. 10 Dec 2019.

Vancouver:

Oraby EA. Gold leaching in thiosulfate solutions and its environmental effects compared with cyanide . [Internet] [Thesis]. Curtin University of Technology; 2009. [cited 2019 Dec 10]. Available from: http://hdl.handle.net/20.500.11937/148.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Oraby EA. Gold leaching in thiosulfate solutions and its environmental effects compared with cyanide . [Thesis]. Curtin University of Technology; 2009. Available from: http://hdl.handle.net/20.500.11937/148

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of New South Wales

5. Cuttriss, Craig P. The design, specification and economic evaluation of a pressure leach process to recover gold from sulphide concentrates using a plug flow (tube) reactor.

Degree: Chemical Engineering & Industrial Chemistry, Faculty of Applied Science, 1987, University of New South Wales

URL: http://handle.unsw.edu.au/1959.4/58250 ; https://unsworks.unsw.edu.au/fapi/datastream/unsworks:45659/SOURCE02?view=true

Subjects/Keywords: Thesis Digitisation Program; Leaching; Gold

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APA (6^th Edition):

Cuttriss, C. P. (1987). The design, specification and economic evaluation of a pressure leach process to recover gold from sulphide concentrates using a plug flow (tube) reactor. (Masters Thesis). University of New South Wales. Retrieved from http://handle.unsw.edu.au/1959.4/58250 ; https://unsworks.unsw.edu.au/fapi/datastream/unsworks:45659/SOURCE02?view=true

Chicago Manual of Style (16^th Edition):

Cuttriss, Craig P. “The design, specification and economic evaluation of a pressure leach process to recover gold from sulphide concentrates using a plug flow (tube) reactor.” 1987. Masters Thesis, University of New South Wales. Accessed December 10, 2019. http://handle.unsw.edu.au/1959.4/58250 ; https://unsworks.unsw.edu.au/fapi/datastream/unsworks:45659/SOURCE02?view=true.

MLA Handbook (7^th Edition):

Cuttriss, Craig P. “The design, specification and economic evaluation of a pressure leach process to recover gold from sulphide concentrates using a plug flow (tube) reactor.” 1987. Web. 10 Dec 2019.

Vancouver:

Cuttriss CP. The design, specification and economic evaluation of a pressure leach process to recover gold from sulphide concentrates using a plug flow (tube) reactor. [Internet] [Masters thesis]. University of New South Wales; 1987. [cited 2019 Dec 10]. Available from: http://handle.unsw.edu.au/1959.4/58250 ; https://unsworks.unsw.edu.au/fapi/datastream/unsworks:45659/SOURCE02?view=true.

Council of Science Editors:

Cuttriss CP. The design, specification and economic evaluation of a pressure leach process to recover gold from sulphide concentrates using a plug flow (tube) reactor. [Masters Thesis]. University of New South Wales; 1987. Available from: http://handle.unsw.edu.au/1959.4/58250 ; https://unsworks.unsw.edu.au/fapi/datastream/unsworks:45659/SOURCE02?view=true

University of Guelph

6. Nicol, Eric. An Electrochemical and SERS Study of the Gold-Thiosulfate Interface in the Presence of Copper .

Degree: 2013, University of Guelph

URL: https://atrium.lib.uoguelph.ca/xmlui/handle/10214/6463

► Complementary electrochemical and spectroscopic techniques were used to characterize the behavior and composition of the passive layer formed at the gold-thiosulfate interface in the presence… (more)

Subjects/Keywords: Hydrometallurgy; electrochemistry; leaching; gold; thiosulfate; copper; SERS; Raman

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APA (6^th Edition):

Nicol, E. (2013). An Electrochemical and SERS Study of the Gold-Thiosulfate Interface in the Presence of Copper . (Thesis). University of Guelph. Retrieved from https://atrium.lib.uoguelph.ca/xmlui/handle/10214/6463

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Nicol, Eric. “An Electrochemical and SERS Study of the Gold-Thiosulfate Interface in the Presence of Copper .” 2013. Thesis, University of Guelph. Accessed December 10, 2019. https://atrium.lib.uoguelph.ca/xmlui/handle/10214/6463.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Nicol, Eric. “An Electrochemical and SERS Study of the Gold-Thiosulfate Interface in the Presence of Copper .” 2013. Web. 10 Dec 2019.

Vancouver:

Nicol E. An Electrochemical and SERS Study of the Gold-Thiosulfate Interface in the Presence of Copper . [Internet] [Thesis]. University of Guelph; 2013. [cited 2019 Dec 10]. Available from: https://atrium.lib.uoguelph.ca/xmlui/handle/10214/6463.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Nicol E. An Electrochemical and SERS Study of the Gold-Thiosulfate Interface in the Presence of Copper . [Thesis]. University of Guelph; 2013. Available from: https://atrium.lib.uoguelph.ca/xmlui/handle/10214/6463

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Stellenbosch University

7. Annandale, Gideon Johannes. An evaluation of liberation models for the prediction of diagnostic leaching results.

Degree: M. Ing., 1995, Stellenbosch University

URL: http://hdl.handle.net/10019.1/54645

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ENGLISH ABSTRACT: The interrelationship between mineral liberation and leaching behaviour of a gold ore is ill defined and lacks understanding mainly due to the complexity… (more)

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ENGLISH ABSTRACT: The interrelationship between mineral liberation and leaching behaviour of a gold ore is ill defined and lacks understanding mainly due to the complexity of the individually processes, i.e. leaching and mineral liberation. An understanding of this relationship could result in lower costs, since an increase in the efficiency of gold dissolution and a decrease in costs related to the crushing and grinding operations, could be expected. Diagnostic leaching was used as the analytical method to investigate the mineralogy (gold deportment) of various gold-bearing ores designating from different goldfields in South Africa. A thorough literature survey was also conducted to determine the availability of theoretical models which could describe the relationship between liberation and leaching behaviour. From the experimental results obtained, it was concluded that the leachability of an ore is not only dependent on the degree of liberation of that ore when comminuted, but that it is also very much dependent on the degree of exposure of gold grains throughout the whole of the ore. It was found that all the theoretical liberation and exposure models underestimated the amount of leachable gold in each particle size fraction, mainly due to the neglecting of exposed gold grains situated in minor cracks and fractures. It became evident in this research, that in order to model the leachability of gold fundamentally, the data obtained from diagnostic leaching tests alone are insufficient. Data concerning the amounts of gold bearing minerals, present in the ores as well as SEM data of the gold grains, are needed together with diagnostic leaching results. However, an empirical model was developed that predicts the degree of liberation (leachability) of an ore milled to 70% -75μm fairly accurately as a first attempt to model this highly complex process. The degree of liberation (leachability) was found to be a function of the particle size and the gold deportment of the unmilled ore. It was decided to extend the King liberation model and the exposure model developed by Hsih and co-workers empirically to provide for the fraction of gold not directly related to liberation. Both the models showed good agreements with the experimental results. Neural network analysis of the diagnostic leaching results were done with partial success, but unfortunately more data is still needed to assist in the development of an accurate leaching or liberation model.

AFRIKAANSE OPSOMMING: Weens die komplekse aard van die mineraalvrystelling- en logings prosesse, word die verwantskap tussen mineraal vrystelling en die logingsgedrag van 'n goud erts nie goed verstaan nie. Aangesien hoë kostes verbonde is aan die vergruising- en die maalproses van die ertse, is dit belangrik om hierdie verwantskap goed te verstaan. Dit kan ook tot gevolg hê dat die effektiwiteit waarmee die goud opgelos word, verhoog word, wat op sy beurt tot laer kostes sal lei. Die analitiese metode, diagnostiese loging, is gebruik om…

Advisors/Committee Members: Lorenzen, L, van Deventer, J. S. J., Stellenbosch University. Faculty of Engineering. Department of Process Engineering..

Subjects/Keywords: Leaching; Gold ores – Metallurgy; Gold – Metallurgy; Dissertations – Metallurgy; UCTD

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APA (6^th Edition):

Annandale, G. J. (1995). An evaluation of liberation models for the prediction of diagnostic leaching results. (Masters Thesis). Stellenbosch University. Retrieved from http://hdl.handle.net/10019.1/54645

Chicago Manual of Style (16^th Edition):

Annandale, Gideon Johannes. “An evaluation of liberation models for the prediction of diagnostic leaching results.” 1995. Masters Thesis, Stellenbosch University. Accessed December 10, 2019. http://hdl.handle.net/10019.1/54645.

MLA Handbook (7^th Edition):

Annandale, Gideon Johannes. “An evaluation of liberation models for the prediction of diagnostic leaching results.” 1995. Web. 10 Dec 2019.

Vancouver:

Annandale GJ. An evaluation of liberation models for the prediction of diagnostic leaching results. [Internet] [Masters thesis]. Stellenbosch University; 1995. [cited 2019 Dec 10]. Available from: http://hdl.handle.net/10019.1/54645.

Council of Science Editors:

Annandale GJ. An evaluation of liberation models for the prediction of diagnostic leaching results. [Masters Thesis]. Stellenbosch University; 1995. Available from: http://hdl.handle.net/10019.1/54645

8. Isildar, Arda. Biological versus chemical leaching of electronic waste for copper and gold recovery : Valorisation des déchets d'équipements électriques et électroniques (DEEE) par différentes approches bio/hydrométallurgiques : application au cas du cuivre et de l’or.

Degree: Docteur es, Sciences et Techniques de l'Environnement, 2016, Université Paris-Est

URL: http://www.theses.fr/2016PESC1125

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Le bien-être de notre société dépend directement de plusieurs métaux tels que les métaux communs, les métaux précieux et, de plus en plus, les terres… (more)

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Le bien-être de notre société dépend directement de plusieurs métaux tels que les métaux communs, les métaux précieux et, de plus en plus, les terres rares (TR). L’utilisation de ces métaux s’est développée dans de nombreuses applications, notamment pour les équipements électriques et électroniques (EEE), et leur approvisionnement interrompu est un enjeu majeur. Les appareils électroniques modernes contiennent jusqu’à 60 métaux différents. Il y a un intérêt grandissant pour les sources secondaires de ces métaux, en particulier les déchets d’équipements électriques et électroniques (DEEE), afin de compenser des potentiels manques d’approvisionnement. Cette thèse de doctorat montre les avantages et les inconvénients des approches biologiques et chimiques, ainsi que des avancées et perspectives dans le développement de procédés viables for la récupération des métaux des DEEE. Un nouveau procédé for la récupération des métaux des DEEE est décrit et une évaluation économique est fournie. Les cartes de circuits imprimés (CCI) des ordinateurs de bureau, des ordinateurs portables, des téléphones mobiles et des serveurs de télécommunications ont été étudiées. Les CCI jetées contenaient des concentration en métaux dans la gamme (% du poids) cuivre (Cu) 17,6 - 39,0 / fer (Fe) 0,7 - 7,5 / aluminium (Al) 1,0 - 5,5 / nickel (Ni) 0,2 - 1,1 / zinc (Zn) 0,3 - 1,2 , ainsi que de l’or (Au) (en ppm) 21 - 320. Une analyse multicritère (AMC) utilisant la méthodologie du processus d’analyse hiérarchique (PAH) a été appliquée pour la sélection de la technologie de récupération des métaux la plus adaptée. Une preuve du concept d’extraction par une double étape de biolixiviation est fournie, dans laquelle 98,4% et 44,0% de cuivre et d’or, respectivement, ont été extrait. Cette procédure d’extraction à deux étapes a aussi été appliquée pour la lixiviation chimique des métaux des CCI. La lixiviation du Cu a été effectuée dans un mélange acide d’H2SO4 et d’H2O2, alors que l’Au a été extrait par du S2O32− dans un milieu NH4+, catalysé par CuSO4. Avec les conditions opératoires optimales, 99,2% et 92,2% de Cu et d’Au, respectivement, ont été extrait de ces matériaux. La récupération sélective du Cu du lixiviat de biolixiviation a été étudiée en utilisant la précipitation sulfurée et l’extraction électrolytique (electrowinning). Le Cu a été récupéré de manière sélective en 50 min sur la cathode à une densité de courant de 50 mA, avec une efficacité de 97,8% et une purité de 65,0%. L’analyse technico-économique et l’évaluation de la viabilité environnementale de la nouvelle technologie à un stade précoce de développement ont été étudiées

The well-being of the society depends on a number of metals, including base metals, precious metals and increasingly rare earth elements (REE). The usage of these metals increased in numerous applications, including electrical and electronic equipment (EEE), and their interrupted supply is at stake. There is an increasing interest in the secondary sources of these metals, particularly waste electrical and…

Advisors/Committee Members: Van Hullebusch, Eric (thesis director), Rossano, Stéphanie (thesis director).

Subjects/Keywords: Bio/hydrométallurgie; Lixivation; Deee; Cuivre; Or; Valorisation; Bioleaching; Leaching; Electronic waste; Copper; Gold; Recovery

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APA (6^th Edition):

Isildar, A. (2016). Biological versus chemical leaching of electronic waste for copper and gold recovery : Valorisation des déchets d'équipements électriques et électroniques (DEEE) par différentes approches bio/hydrométallurgiques : application au cas du cuivre et de l’or. (Doctoral Dissertation). Université Paris-Est. Retrieved from http://www.theses.fr/2016PESC1125

Chicago Manual of Style (16^th Edition):

Isildar, Arda. “Biological versus chemical leaching of electronic waste for copper and gold recovery : Valorisation des déchets d'équipements électriques et électroniques (DEEE) par différentes approches bio/hydrométallurgiques : application au cas du cuivre et de l’or.” 2016. Doctoral Dissertation, Université Paris-Est. Accessed December 10, 2019. http://www.theses.fr/2016PESC1125.

MLA Handbook (7^th Edition):

Isildar, Arda. “Biological versus chemical leaching of electronic waste for copper and gold recovery : Valorisation des déchets d'équipements électriques et électroniques (DEEE) par différentes approches bio/hydrométallurgiques : application au cas du cuivre et de l’or.” 2016. Web. 10 Dec 2019.

Vancouver:

Isildar A. Biological versus chemical leaching of electronic waste for copper and gold recovery : Valorisation des déchets d'équipements électriques et électroniques (DEEE) par différentes approches bio/hydrométallurgiques : application au cas du cuivre et de l’or. [Internet] [Doctoral dissertation]. Université Paris-Est; 2016. [cited 2019 Dec 10]. Available from: http://www.theses.fr/2016PESC1125.

Council of Science Editors:

Isildar A. Biological versus chemical leaching of electronic waste for copper and gold recovery : Valorisation des déchets d'équipements électriques et électroniques (DEEE) par différentes approches bio/hydrométallurgiques : application au cas du cuivre et de l’or. [Doctoral Dissertation]. Université Paris-Est; 2016. Available from: http://www.theses.fr/2016PESC1125

University of New South Wales

9. Kim, You Jin. Studies on gold dissolution and loss of gold due to gangue minerals in chloride solutions.

Degree: Mining Engineering, 1995, University of New South Wales

URL: http://handle.unsw.edu.au/1959.4/57146 ; https://unsworks.unsw.edu.au/fapi/datastream/unsworks:42689/SOURCE01?view=true

Subjects/Keywords: Thesis Digitisation Program; Gold ores; Leaching

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APA (6^th Edition):

Kim, Y. J. (1995). Studies on gold dissolution and loss of gold due to gangue minerals in chloride solutions. (Doctoral Dissertation). University of New South Wales. Retrieved from http://handle.unsw.edu.au/1959.4/57146 ; https://unsworks.unsw.edu.au/fapi/datastream/unsworks:42689/SOURCE01?view=true

Chicago Manual of Style (16^th Edition):

Kim, You Jin. “Studies on gold dissolution and loss of gold due to gangue minerals in chloride solutions.” 1995. Doctoral Dissertation, University of New South Wales. Accessed December 10, 2019. http://handle.unsw.edu.au/1959.4/57146 ; https://unsworks.unsw.edu.au/fapi/datastream/unsworks:42689/SOURCE01?view=true.

MLA Handbook (7^th Edition):

Kim, You Jin. “Studies on gold dissolution and loss of gold due to gangue minerals in chloride solutions.” 1995. Web. 10 Dec 2019.

Vancouver:

Kim YJ. Studies on gold dissolution and loss of gold due to gangue minerals in chloride solutions. [Internet] [Doctoral dissertation]. University of New South Wales; 1995. [cited 2019 Dec 10]. Available from: http://handle.unsw.edu.au/1959.4/57146 ; https://unsworks.unsw.edu.au/fapi/datastream/unsworks:42689/SOURCE01?view=true.

Council of Science Editors:

Kim YJ. Studies on gold dissolution and loss of gold due to gangue minerals in chloride solutions. [Doctoral Dissertation]. University of New South Wales; 1995. Available from: http://handle.unsw.edu.au/1959.4/57146 ; https://unsworks.unsw.edu.au/fapi/datastream/unsworks:42689/SOURCE01?view=true

University of Guelph

10. Smith, Scott R. Electrochemical and SERS Studies of the Interfacial Behaviour of Thiosulfate and Polythionate Solutions with Gold Electrodes and Oxide Ores .

Degree: 2015, University of Guelph

URL: https://atrium.lib.uoguelph.ca/xmlui/handle/10214/9344

► This thesis presents electrochemical and SERS studies of the interfacial interactions of thiosulfate and some related electrolytes with pure gold electrodes and oxide ores. In… (more)

▼ This thesis presents electrochemical and SERS studies of the interfacial interactions of thiosulfate and some related electrolytes with pure gold electrodes and oxide ores. In the first study, development of a nanoparticle modified gold electrode is presented with the first recorded SERS characterization of a hydrophilic self-assembled monolayer (SAM) of 1-thio-β-D-glucose (TG) adsorbed to a gold surface using electrochemical surface enhanced Raman spectroscopy (EC-SERS). Gold nanoparticles were deposited on the gold electrode surface and then subjected to electrochemical desorption to remove all contaminants. The TG SAM was observed as partially oxidized in the -0.60 to -0.20 V vs. SCE region with a large retention of water near the gold surface. In the second study, SERS spectra of gold nanorods (AuNRs) exposed to electrolyte solutions of tetrathionate, trithionate, sulfide, the [Au(S2O3)2]3- complex, and thiosulfate are discussed. The band positions of each species are compared to those recorded with the thiosulfate electrolyte over an extended period of time. Initially, in a thiosulfate electrolyte the interfacial region consisted of thiosulfate and the gold thiosulfate complex. At longer exposure it was concluded the layer that inhibits gold dissolution is predominantly sulfides, cyclo-S8, and polysulfide chains. Using shell-isolated nanoparticles (SHINs), the interaction of thiosulfate with bulk gold electrodes or oxides ore samples was studied with SERS. A novel analytical procedure to correct for fluctuations in surface enhancement is presented. The relative change in the quantity of the [Au(S2O3)2]3- complex, and elemental sulfur bands related to the passive layer, were found to coincide well with the electrochemically determined gold leaching rate. Furthermore, the first reported interaction and subsequent removal of several passive layer constituents from the gold surface by copper and ammonia is presented. Finally, differences in passive layer growth were observed between untreated and pressure-oxidation (POX) treated oxide ore samples exposed to the thiosulfate electrolytes. The passive layer observed of the untreated oxide ore-SHINs-electrolyte interface was found to contain metal-sulfides and polysulfide chains (Sn/Sn2-) after longer exposure. In comparison, the passive layer observed with the POX treated sample was found to be predominantly metal-sulfides with only a small quantity of polysulfide chains. The pretreatment process was concluded to destroy or sufficiently inactivate minerals present in the ore that catalyze thiosulfate decomposition. Advisors/Committee Members: Lipkowski, Jacek (advisor).

Subjects/Keywords: gold leaching; surface enhanced Raman spectroscopy; shell-isolated nanoparticles; electrochemistry; oxide ores

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APA (6^th Edition):

Smith, S. R. (2015). Electrochemical and SERS Studies of the Interfacial Behaviour of Thiosulfate and Polythionate Solutions with Gold Electrodes and Oxide Ores . (Thesis). University of Guelph. Retrieved from https://atrium.lib.uoguelph.ca/xmlui/handle/10214/9344

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Smith, Scott R. “Electrochemical and SERS Studies of the Interfacial Behaviour of Thiosulfate and Polythionate Solutions with Gold Electrodes and Oxide Ores .” 2015. Thesis, University of Guelph. Accessed December 10, 2019. https://atrium.lib.uoguelph.ca/xmlui/handle/10214/9344.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Smith, Scott R. “Electrochemical and SERS Studies of the Interfacial Behaviour of Thiosulfate and Polythionate Solutions with Gold Electrodes and Oxide Ores .” 2015. Web. 10 Dec 2019.

Vancouver:

Smith SR. Electrochemical and SERS Studies of the Interfacial Behaviour of Thiosulfate and Polythionate Solutions with Gold Electrodes and Oxide Ores . [Internet] [Thesis]. University of Guelph; 2015. [cited 2019 Dec 10]. Available from: https://atrium.lib.uoguelph.ca/xmlui/handle/10214/9344.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Smith SR. Electrochemical and SERS Studies of the Interfacial Behaviour of Thiosulfate and Polythionate Solutions with Gold Electrodes and Oxide Ores . [Thesis]. University of Guelph; 2015. Available from: https://atrium.lib.uoguelph.ca/xmlui/handle/10214/9344

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Pretoria

11. Lotter, Nadia. Cyanide volatilisation from gold leaching operations and tailing facilities.

Degree: Materials Science and Metallurgical Engineering, 2007, University of Pretoria

URL: http://hdl.handle.net/2263/23975

► In recent years, emissions of hydrogen cyanide from metallurgical operations have received renewed attention by legislative bodies, leading to the need for a reliable quantification… (more)

▼ In recent years, emissions of hydrogen cyanide from metallurgical operations have received renewed attention by legislative bodies, leading to the need for a reliable quantification method for HCN volatilisation. Subsequently, the purpose of this project, launched by Anglogold Ashanti Ltd. and in collaboration with MINTEK and the University of Pretoria, was to develop a prediction model for cyanide volatilisation from plant operations and tailings storage facilities in South Africa. The study was done in four stages, the first being a laboratory study of the equilibrium behaviour of hydrogen cyanide. Henry’s Law constant (kH) was determined at different solution cyanide concentrations, salinities and temperatures. A value for kH was established at 0.082 atm.L/mol, which was found to be independent on the solution cyanide concentration between 10 and 200 ppm cyanide. In addition, the effect of temperature on kH was found to be negligible at solution temperatures between 20 and 35ºC. It was also concluded that high salinities increase kH and promote volatilisation, but this effect was negligible at the typical salinity levels found in South African process water. The second stage entailed a detailed study of the mass transfer coefficient, KOL, for hydrogen cyanide from cyanide solutions and pulp mixtures, both in the laboratory and on-site. It followed from this investigation that the most important parameters affecting KOL are the HCN (aq) concentration in the liquid, the wind velocity across the solution or pulp surface, expressed in terms of a Roughness Reynolds number, Re*, and the moisture content, or solid to liquid ratio, of the pulp. Furthermore, it was concluded that KOL is highly sensitive to HCN (aq) concentrations at low concentrations, while it becomes rather insensitive to HCN (aq) at concentrations above 20 ppm HCN (aq) . The data generated by the laboratory and on-site test work was incorporated into the development of an empirical prediction model, based on the Roughness Reynolds number (Re*), moisture content (M), and aqueous cyanide concentration (HCN(aq) ) which may be described by the following equation: KOL= a Re*b Mc HCN(aq)d + e The model coefficients were subsequently determined for application of the model to leach tanks, adsorption tanks, tailing storage facility surfaces and return water dams. The calculated model predictions for KOL were in excellent agreement with the measured test work data. Finally, the prediction model was validated at the leach and adsorption sections of a selected gold plant and a selected tailings storage facility. The model predicted that 9% of the cyanide lost in the leach and adsorption section could be attributed to HCN volatilisation. As for the tailings storage facility, the model assigned 63% of the cyanide lost from the tailings storage facility to HCN volatilisation, of which 95% occurred from the area on the tailings dam surface covered in a thin liquid film. It is recommended that the current methods available for the… Advisors/Committee Members: Prof R F Sandenbergh (advisor), Prof M J Nicol (advisor).

Subjects/Keywords: Hydrocyanic acid; Leaching; Tailings metallurgy; Gold metallurgy; UCTD

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Lotter, N. (2007). Cyanide volatilisation from gold leaching operations and tailing facilities. (Masters Thesis). University of Pretoria. Retrieved from http://hdl.handle.net/2263/23975

Chicago Manual of Style (16^th Edition):

Lotter, Nadia. “Cyanide volatilisation from gold leaching operations and tailing facilities.” 2007. Masters Thesis, University of Pretoria. Accessed December 10, 2019. http://hdl.handle.net/2263/23975.

MLA Handbook (7^th Edition):

Lotter, Nadia. “Cyanide volatilisation from gold leaching operations and tailing facilities.” 2007. Web. 10 Dec 2019.

Vancouver:

Lotter N. Cyanide volatilisation from gold leaching operations and tailing facilities. [Internet] [Masters thesis]. University of Pretoria; 2007. [cited 2019 Dec 10]. Available from: http://hdl.handle.net/2263/23975.

Council of Science Editors:

Lotter N. Cyanide volatilisation from gold leaching operations and tailing facilities. [Masters Thesis]. University of Pretoria; 2007. Available from: http://hdl.handle.net/2263/23975

University of Pretoria

12. [No author]. Cyanide volatilisation from gold leaching operations and tailing facilities .

Degree: 2007, University of Pretoria

URL: http://upetd.up.ac.za/thesis/available/etd-04162007-153634/

► In recent years, emissions of hydrogen cyanide from metallurgical operations have received renewed attention by legislative bodies, leading to the need for a reliable quantification… (more)

▼ In recent years, emissions of hydrogen cyanide from metallurgical operations have received renewed attention by legislative bodies, leading to the need for a reliable quantification method for HCN volatilisation. Subsequently, the purpose of this project, launched by Anglogold Ashanti Ltd. and in collaboration with MINTEK and the University of Pretoria, was to develop a prediction model for cyanide volatilisation from plant operations and tailings storage facilities in South Africa. The study was done in four stages, the first being a laboratory study of the equilibrium behaviour of hydrogen cyanide. Henry’s Law constant (kH) was determined at different solution cyanide concentrations, salinities and temperatures. A value for kH was established at 0.082 atm.L/mol, which was found to be independent on the solution cyanide concentration between 10 and 200 ppm cyanide. In addition, the effect of temperature on kH was found to be negligible at solution temperatures between 20 and 35ºC. It was also concluded that high salinities increase kH and promote volatilisation, but this effect was negligible at the typical salinity levels found in South African process water. The second stage entailed a detailed study of the mass transfer coefficient, KOL, for hydrogen cyanide from cyanide solutions and pulp mixtures, both in the laboratory and on-site. It followed from this investigation that the most important parameters affecting KOL are the HCN (aq) concentration in the liquid, the wind velocity across the solution or pulp surface, expressed in terms of a Roughness Reynolds number, Re*, and the moisture content, or solid to liquid ratio, of the pulp. Furthermore, it was concluded that KOL is highly sensitive to HCN (aq) concentrations at low concentrations, while it becomes rather insensitive to HCN (aq) at concentrations above 20 ppm HCN (aq) . The data generated by the laboratory and on-site test work was incorporated into the development of an empirical prediction model, based on the Roughness Reynolds number (Re*), moisture content (M), and aqueous cyanide concentration (HCN(aq) ) which may be described by the following equation: KOL= a Re*b Mc HCN(aq)d + e The model coefficients were subsequently determined for application of the model to leach tanks, adsorption tanks, tailing storage facility surfaces and return water dams. The calculated model predictions for KOL were in excellent agreement with the measured test work data. Finally, the prediction model was validated at the leach and adsorption sections of a selected gold plant and a selected tailings storage facility. The model predicted that 9% of the cyanide lost in the leach and adsorption section could be attributed to HCN volatilisation. As for the tailings storage facility, the model assigned 63% of the cyanide lost from the tailings storage facility to HCN volatilisation, of which 95% occurred from the area on the tailings dam surface covered in a thin liquid film. It is recommended that the current methods available for the… Advisors/Committee Members: Prof R F Sandenbergh (advisor), Prof M J Nicol (advisor).

Subjects/Keywords: Hydrocyanic acid; Leaching; Tailings metallurgy; Gold metallurgy; UCTD

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APA (6^th Edition):

author], [. (2007). Cyanide volatilisation from gold leaching operations and tailing facilities . (Masters Thesis). University of Pretoria. Retrieved from http://upetd.up.ac.za/thesis/available/etd-04162007-153634/

Chicago Manual of Style (16^th Edition):

author], [No. “Cyanide volatilisation from gold leaching operations and tailing facilities .” 2007. Masters Thesis, University of Pretoria. Accessed December 10, 2019. http://upetd.up.ac.za/thesis/available/etd-04162007-153634/.

MLA Handbook (7^th Edition):

author], [No. “Cyanide volatilisation from gold leaching operations and tailing facilities .” 2007. Web. 10 Dec 2019.

Vancouver:

author] [. Cyanide volatilisation from gold leaching operations and tailing facilities . [Internet] [Masters thesis]. University of Pretoria; 2007. [cited 2019 Dec 10]. Available from: http://upetd.up.ac.za/thesis/available/etd-04162007-153634/.

Council of Science Editors:

author] [. Cyanide volatilisation from gold leaching operations and tailing facilities . [Masters Thesis]. University of Pretoria; 2007. Available from: http://upetd.up.ac.za/thesis/available/etd-04162007-153634/

13. GIRALDO GOMEZ, IVAN ALEJANDRO. New insight on Gold and Copper leaching from waste printed circuit boards by Chromobacterium violaceum : Three steps process .

Degree: 2015, Universidad de los Andes

URL: https://documentodegrado.uniandes.edu.co/documentos/8089.pdf

► Actuante, la alta demanda de equipos eléctricos y electrónicos por parte de la sociedad, está generando grandes cantidades de WEEE (Waste Electrical and Electronic Equipment).… (more)

Subjects/Keywords: Biodegradation - Chromobacterium violaceum – Leaching – Gold - Electronic waste

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APA (6^th Edition):

GIRALDO GOMEZ, I. A. (2015). New insight on Gold and Copper leaching from waste printed circuit boards by Chromobacterium violaceum : Three steps process . (Thesis). Universidad de los Andes. Retrieved from https://documentodegrado.uniandes.edu.co/documentos/8089.pdf

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

GIRALDO GOMEZ, IVAN ALEJANDRO. “New insight on Gold and Copper leaching from waste printed circuit boards by Chromobacterium violaceum : Three steps process .” 2015. Thesis, Universidad de los Andes. Accessed December 10, 2019. https://documentodegrado.uniandes.edu.co/documentos/8089.pdf.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

GIRALDO GOMEZ, IVAN ALEJANDRO. “New insight on Gold and Copper leaching from waste printed circuit boards by Chromobacterium violaceum : Three steps process .” 2015. Web. 10 Dec 2019.

Vancouver:

GIRALDO GOMEZ IA. New insight on Gold and Copper leaching from waste printed circuit boards by Chromobacterium violaceum : Three steps process . [Internet] [Thesis]. Universidad de los Andes; 2015. [cited 2019 Dec 10]. Available from: https://documentodegrado.uniandes.edu.co/documentos/8089.pdf.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

GIRALDO GOMEZ IA. New insight on Gold and Copper leaching from waste printed circuit boards by Chromobacterium violaceum : Three steps process . [Thesis]. Universidad de los Andes; 2015. Available from: https://documentodegrado.uniandes.edu.co/documentos/8089.pdf

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

14. Fosu, Bernard. Experimental investigation of recovering gold from maghemite-rich magnetic concentrates by roasting.

Degree: MS(M.S.), Metallurgical and Materials Engineering, 2016, Colorado School of Mines

URL: http://hdl.handle.net/11124/170022

► Roasting of double refractory ores found in the Carlin Trend is necessary to oxidize the sulfides and remove the organic matter prior to leaching for… (more)

▼ Roasting of double refractory ores found in the Carlin Trend is necessary to oxidize the sulfides and remove the organic matter prior to leaching for gold extraction. Oxidation of the iron sulfides often leads to the formation of maghemite, an intermediary product of non-porous calcine, which negatively affects cyanide leaching. Magnetic recovery circuits are often used to capture the highly magnetic maghemite from the leach tails. The magnetic concentrates are either routed to autoclaves for pretreatment or as part of the raw feed to the roasters. The component that goes into the autoclave is ground finer prior to pressure oxidation. This fine grinding presents an added processing cost. The main objective of this project was to explore the possibility of recovering gold from the maghemite-rich magnetic concentrates by roasting. Preliminary roasting tests were conducted on pure maghemite standard samples and the results obtained were used as a basis for further roasting the magnetic concentrate samples. The magnetic concentrates were characterized before and after the experiments to determine any changes in mineralogy, composition, and surface characteristics. Roasting at 650 °C or higher resulted in at least 50% maghemite-to-hematite conversion. The roast calcines were cyanide-leached for gold recovery. Results suggest that roasting improves gold recovery from the magnetic concentrates from no extraction to about 85% extraction. Enriching the roast air with oxygen did not yield in any appreciable increase in gold recovery. Additional test results have also shown that finer grinding of the magnetic concentrates and/or prolonging the roasting time barely reduces the arsenic, organic carbon and sulfide sulfur content of the resulting calcine. Therefore, these processes do not result in any appreciable increase in gold recovery. Even though roasting has been proven as a feasible means of recovering appreciable amount of the gold held in the maghemite-rich magnetic concentrates, it is highly recommended that its application on a large scale be preceded by a detailed economic analysis. Advisors/Committee Members: Taylor, Patrick R. (advisor), Anderson, Corby G. (committee member), Spiller, D. Erik (committee member).

Subjects/Keywords: Gold; Hematite; Leaching; Maghemite; Refractory; Roasting

…and is detrimental to subsequent cyanide leaching. Gold deportment to tails, caused mainly… …further reprocessed to recover the included gold. After cyanide leaching, maghemite containing… …and is available for leaching. Free milling ores are easy to treat. Gold in such ores is… …leaching with gold recovery by CIP/CIL [2, 17]. In free milling ores, the ore is first… …and continue to serve as pregrobbers in the subsequent gold leaching process.” La Brooy et…

13 more images…

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Fosu, B. (2016). Experimental investigation of recovering gold from maghemite-rich magnetic concentrates by roasting. (Masters Thesis). Colorado School of Mines. Retrieved from http://hdl.handle.net/11124/170022

Chicago Manual of Style (16^th Edition):

Fosu, Bernard. “Experimental investigation of recovering gold from maghemite-rich magnetic concentrates by roasting.” 2016. Masters Thesis, Colorado School of Mines. Accessed December 10, 2019. http://hdl.handle.net/11124/170022.

MLA Handbook (7^th Edition):

Fosu, Bernard. “Experimental investigation of recovering gold from maghemite-rich magnetic concentrates by roasting.” 2016. Web. 10 Dec 2019.

Vancouver:

Fosu B. Experimental investigation of recovering gold from maghemite-rich magnetic concentrates by roasting. [Internet] [Masters thesis]. Colorado School of Mines; 2016. [cited 2019 Dec 10]. Available from: http://hdl.handle.net/11124/170022.

Council of Science Editors:

Fosu B. Experimental investigation of recovering gold from maghemite-rich magnetic concentrates by roasting. [Masters Thesis]. Colorado School of Mines; 2016. Available from: http://hdl.handle.net/11124/170022

University of Toronto

15. Peters, Samuel. An Investigation of the Role of Sodium Carbonate and Silica in the Neutral/Alkaline Pressure Oxidation of Pyrite.

Degree: 2010, University of Toronto

URL: http://hdl.handle.net/1807/32915

►

Pressure oxidation of refractory gold ores containing carbonate minerals is conducted under neutral/alkaline conditions in order to promote fast kinetics, reduced reagent consumption and suppressing… (more)

Subjects/Keywords: pyrite oxidation; pressure oxidation; pressure oxidation of pyrite; alkaline pressure oxidation; sulphide leaching; silica coating; autoclave; refractory gold; hydrometallurgy; 0542

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APA (6^th Edition):

Peters, S. (2010). An Investigation of the Role of Sodium Carbonate and Silica in the Neutral/Alkaline Pressure Oxidation of Pyrite. (Masters Thesis). University of Toronto. Retrieved from http://hdl.handle.net/1807/32915

Chicago Manual of Style (16^th Edition):

Peters, Samuel. “An Investigation of the Role of Sodium Carbonate and Silica in the Neutral/Alkaline Pressure Oxidation of Pyrite.” 2010. Masters Thesis, University of Toronto. Accessed December 10, 2019. http://hdl.handle.net/1807/32915.

MLA Handbook (7^th Edition):

Peters, Samuel. “An Investigation of the Role of Sodium Carbonate and Silica in the Neutral/Alkaline Pressure Oxidation of Pyrite.” 2010. Web. 10 Dec 2019.

Vancouver:

Peters S. An Investigation of the Role of Sodium Carbonate and Silica in the Neutral/Alkaline Pressure Oxidation of Pyrite. [Internet] [Masters thesis]. University of Toronto; 2010. [cited 2019 Dec 10]. Available from: http://hdl.handle.net/1807/32915.

Council of Science Editors:

Peters S. An Investigation of the Role of Sodium Carbonate and Silica in the Neutral/Alkaline Pressure Oxidation of Pyrite. [Masters Thesis]. University of Toronto; 2010. Available from: http://hdl.handle.net/1807/32915

Indian Institute of Science

16. Chandraprabha, M N. Studies On Bio-Oxidation A Refractory Gold Containing Sulphidic Concentrate With Respect To Optimization And Modeling.

Degree: 2000, Indian Institute of Science

URL: http://hdl.handle.net/2005/188

► Although bacterial leaching of sulphidic minerals is a well-known phenomenon, it is only in the last ten years that full-scale bacterial leaching plants have been… (more)

▼ Although bacterial leaching of sulphidic minerals is a well-known phenomenon, it is only in the last ten years that full-scale bacterial leaching plants have been commissioned for gold processing. In order for bacterial leaching to compete successfully with other pretreatment processes for refractory ores, particularly with established technologies such as roasting and pressure leaching, it needs to be efficient. This requires the optimization of the parameters affecting the leaching reaction and the growth of bacteria. The entire biotreatment process is agitation leaching, carried out in stirred reactors or Pachuca type reactors. The bacterial oxidation is a complex reaction involving gaseous, liquid and solid phases. The interactions are highly complex, and analysis is complicated by the presence of solids in the leaching medium. Inspite of the amount of research that has been performed, kinetic and process models are underdeveloped. Since kinetic data varies widely with the type and source of concentrate, experimental data should be generated before doing the full-scale reactor design. In sizing reactors for a commercial scale process, it would be useful to have a mathematical model that one could use to predict the amount and rate of release of metal, as a function of the various operating parameters of the system. G.R.Halli arsenical gold sulphide concentrate obtained from Hutti Gold Mines Ltd., Karnataka, was chosen for our study, because of its high refractoriness. An indegenous strain of Thiobacillus ferrooxidans was used for biooxidation. The experiments were conducted in a well-agitated stirred tank reactor under controlled conditions. Sparged air was supplemented with carbon-dioxide for optimized growth. In this work, more than 90% gold and 95% silver could be recovered from the sulphidic gold concentrate when bioleaching was used ahead of cyanidation, compared to 40% and 50% by direct cyanidation. A generalized model, which accounts for both direct bacterial attack and indirect chemical leaching, has been proposed for the biooxidation of refractory gold concentrates. The bacterial balance, therefore, accounts for its growth both on solid substrate and in solution, and for the attachment to and detachment from the surface. The overall process is considered to consist of several sub-processes, each of which can be described in terms of a mechanism and related rate expressions. These sub-processes were studied seperately under kinetically controlled conditions. The key parameters appearing in the rate equations were evaluated using the experimental data. Since the refractory concentrate contains pyrite and arsenopyrite as the major leachable entities, leaching studies have been done on pure pyrite and arsenopyrite as test minerals and the key parameters in the rate equations are evaluated using this data. The model so developed is tested with the leaching kinetics of the concentrate. The growth of bacteria is dependent on the availability of the substrate, ferrous iron, and the dependence is modelled by… Advisors/Committee Members: Natarajan, K A.

Subjects/Keywords: Metallurgy; Gold-Metallurgy; Gold-Refractures; Refractory Gold Ores; Bacterial Leaching; Gold Processing; Refractory Ores; Ferrous Iron Oxidation; Bacterial Oxidation

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APA (6^th Edition):

Chandraprabha, M. N. (2000). Studies On Bio-Oxidation A Refractory Gold Containing Sulphidic Concentrate With Respect To Optimization And Modeling. (Thesis). Indian Institute of Science. Retrieved from http://hdl.handle.net/2005/188

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Chandraprabha, M N. “Studies On Bio-Oxidation A Refractory Gold Containing Sulphidic Concentrate With Respect To Optimization And Modeling.” 2000. Thesis, Indian Institute of Science. Accessed December 10, 2019. http://hdl.handle.net/2005/188.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Chandraprabha, M N. “Studies On Bio-Oxidation A Refractory Gold Containing Sulphidic Concentrate With Respect To Optimization And Modeling.” 2000. Web. 10 Dec 2019.

Vancouver:

Chandraprabha MN. Studies On Bio-Oxidation A Refractory Gold Containing Sulphidic Concentrate With Respect To Optimization And Modeling. [Internet] [Thesis]. Indian Institute of Science; 2000. [cited 2019 Dec 10]. Available from: http://hdl.handle.net/2005/188.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Chandraprabha MN. Studies On Bio-Oxidation A Refractory Gold Containing Sulphidic Concentrate With Respect To Optimization And Modeling. [Thesis]. Indian Institute of Science; 2000. Available from: http://hdl.handle.net/2005/188

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Colorado School of Mines

17. Lorengo, James Michael. Ferrate iron (Fe6+) as an alternative method for the detoxification of cyanide and cyanide species in gold cyanidation leach tails.

Degree: MS(M.S.), Metallurgical and Materials Engineering, 2007, Colorado School of Mines

URL: http://hdl.handle.net/11124/79399

► The super oxidative properties of ferrate (VI) iron was investigated in an attempt to determine its destruction efficiency on the cyanide ion, cyanide containing species,… (more)

Subjects/Keywords: Gold; Ferrate; Cyanide; Tailings; Leaching; Detoxification; Cyanide process; Precipitation (Chemistry); Leaching; Gold – Metallurgy; Ferrocyanides

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APA (6^th Edition):

Lorengo, J. M. (2007). Ferrate iron (Fe6+) as an alternative method for the detoxification of cyanide and cyanide species in gold cyanidation leach tails. (Masters Thesis). Colorado School of Mines. Retrieved from http://hdl.handle.net/11124/79399

Chicago Manual of Style (16^th Edition):

Lorengo, James Michael. “Ferrate iron (Fe6+) as an alternative method for the detoxification of cyanide and cyanide species in gold cyanidation leach tails.” 2007. Masters Thesis, Colorado School of Mines. Accessed December 10, 2019. http://hdl.handle.net/11124/79399.

MLA Handbook (7^th Edition):

Lorengo, James Michael. “Ferrate iron (Fe6+) as an alternative method for the detoxification of cyanide and cyanide species in gold cyanidation leach tails.” 2007. Web. 10 Dec 2019.

Vancouver:

Lorengo JM. Ferrate iron (Fe6+) as an alternative method for the detoxification of cyanide and cyanide species in gold cyanidation leach tails. [Internet] [Masters thesis]. Colorado School of Mines; 2007. [cited 2019 Dec 10]. Available from: http://hdl.handle.net/11124/79399.

Council of Science Editors:

Lorengo JM. Ferrate iron (Fe6+) as an alternative method for the detoxification of cyanide and cyanide species in gold cyanidation leach tails. [Masters Thesis]. Colorado School of Mines; 2007. Available from: http://hdl.handle.net/11124/79399

Curtin University of Technology

18. Jeffrey, Matthew I. A Kinetic and electrochemical study of the dissolution of gold in aerated cyanide solutions: the role of solid and solution phase purity .

Degree: 1997, Curtin University of Technology

URL: http://hdl.handle.net/20.500.11937/2030

► Over the last 100 Years, the cyanidation process has been the most popular method for recovering gold from its ores. Despite this, there are still… (more)

▼ Over the last 100 Years, the cyanidation process has been the most popular method for recovering gold from its ores. Despite this, there are still efforts to improve the efficiency of the process, particularly as ores become more difficult to treat. Many investigators have studied the cyanidation process, although a large proportion of these studies have obtained contradictory results. This thesis presents a kinetic and electrochemical study of the leaching of gold in cyanide solutions, and emphasis is placed on rationalising the conflicting results which have been published in the past.The leaching rate of gold was measured using a rotating electrochemical quartz crystal microbalance, an instrument which allows the simultaneous measurement of electrochemical data and mass changes at the solid-solution interface in real time. A proportion of this project was devoted to the on-going design of this instrument, and a number of modifications are discussed in detail. Initially, the leaching of gold in cyanide solutions was investigated under conditions of high purity. Under these conditions, it was found that the gold surface is blocked by a passive film, presumably AuCN. The presence of such a film results in the reaction being chemically controlled, and under typical cyanidation conditions (4 mM cyanide, pH 10.0), the rate of dissolution is very low. These kinetic results were supported by complimentary electrochemical studies, which showed that gold is passive in the potential region where cyanidation occurs.The second part of this thesis presents a study of the effect of system purity on the leaching of gold in cyanide solutions. Solution phase purity was investigated by adding controlled amounts of lead or silver to the leach solutions. It was found that in the presence of low concentrations of lead, the dissolution of gold in 20 mM cyanide solutions was oxygen diffusion controlled (as compared to chemical control for gold in the absence of lead). However, high concentrations of lead were found to be detrimental to the leaching process. It is believed that the role of lead is to modify the surface by cementation, hence reducing the effect of the passive film. Silver was also found to be effective at reducing passivation, and the role of silver believed to be similar to that of lead. It was found that unlike lead, high concentrations of silver are not detrimental to the dissolution of gold in cyanide solutions.Solid phase purity was also found to be important in the leaching of gold, and it was found that the leaching of a gold sample which contains 1 % silver is diffusion controlled. This finding is important from an industrial viewpoint, as most native gold contains some silver. Consequently, attempts were made to rationalise the leaching of gold/silver with current plant practice. Discussion on the effect of cyanide and oxygen concentrations, temperature and lead addition is presented.

Subjects/Keywords: solid phase purity; solution phase purity; gold; leaching; cyanide solutions

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APA (6^th Edition):

Jeffrey, M. I. (1997). A Kinetic and electrochemical study of the dissolution of gold in aerated cyanide solutions: the role of solid and solution phase purity . (Thesis). Curtin University of Technology. Retrieved from http://hdl.handle.net/20.500.11937/2030

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Jeffrey, Matthew I. “A Kinetic and electrochemical study of the dissolution of gold in aerated cyanide solutions: the role of solid and solution phase purity .” 1997. Thesis, Curtin University of Technology. Accessed December 10, 2019. http://hdl.handle.net/20.500.11937/2030.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Jeffrey, Matthew I. “A Kinetic and electrochemical study of the dissolution of gold in aerated cyanide solutions: the role of solid and solution phase purity .” 1997. Web. 10 Dec 2019.

Vancouver:

Jeffrey MI. A Kinetic and electrochemical study of the dissolution of gold in aerated cyanide solutions: the role of solid and solution phase purity . [Internet] [Thesis]. Curtin University of Technology; 1997. [cited 2019 Dec 10]. Available from: http://hdl.handle.net/20.500.11937/2030.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Jeffrey MI. A Kinetic and electrochemical study of the dissolution of gold in aerated cyanide solutions: the role of solid and solution phase purity . [Thesis]. Curtin University of Technology; 1997. Available from: http://hdl.handle.net/20.500.11937/2030

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Queens University

19. Xia, Chen. Associated Sulfide Minerals in Thiosulfate Leaching of Gold: Problems and Solutions .

Degree: Mining Engineering, 2010, Queens University

URL: http://hdl.handle.net/1974/5465

► The effects of some associated minerals on thiosulfate gold leaching were studied through thermodynamic analysis and leaching experiments on composite ore samples containing various minerals… (more)

Subjects/Keywords: thiosulfate; gold; ammonia; copper; ethylenediamine; phosphate; pyrite; pyrrhotite; arsenopyrite; chalcopyrite; chalcocite; bornite; galena; lead; Eh-pH; Oxygen; Extraction; Leaching; Pre-aeration; Passivation

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Xia, C. (2010). Associated Sulfide Minerals in Thiosulfate Leaching of Gold: Problems and Solutions . (Thesis). Queens University. Retrieved from http://hdl.handle.net/1974/5465

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Xia, Chen. “Associated Sulfide Minerals in Thiosulfate Leaching of Gold: Problems and Solutions .” 2010. Thesis, Queens University. Accessed December 10, 2019. http://hdl.handle.net/1974/5465.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Xia, Chen. “Associated Sulfide Minerals in Thiosulfate Leaching of Gold: Problems and Solutions .” 2010. Web. 10 Dec 2019.

Vancouver:

Xia C. Associated Sulfide Minerals in Thiosulfate Leaching of Gold: Problems and Solutions . [Internet] [Thesis]. Queens University; 2010. [cited 2019 Dec 10]. Available from: http://hdl.handle.net/1974/5465.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Xia C. Associated Sulfide Minerals in Thiosulfate Leaching of Gold: Problems and Solutions . [Thesis]. Queens University; 2010. Available from: http://hdl.handle.net/1974/5465

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Laurentian University

20. Hmidi, Nuri. Production and characterization of polystyrene resins containing fine activated carbon particles .

Degree: 2017, Laurentian University

URL: https://zone.biblio.laurentian.ca/handle/10219/2857

► The development of high capacity adsorbent using engineered activated carbon fines technology, and their ability to extract gold from solution is presented. The unique feature… (more)

Subjects/Keywords: activated carbon; polystyrene; ion exchange resins; gold loaded fine activated carbon; PSAC; (Polystyrene Activated Carbon) beads; autoclave; stripping; gold recovery; elution; adsorption; desorption; cyanide adsorption/stripping; porosity; surface area; size distribution; leaching; in carbon-in-pulp (CIP); carbon-in-leach (CIL) processes; gold losses; morphology; , resin in pulp (RIP)

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Hmidi, N. (2017). Production and characterization of polystyrene resins containing fine activated carbon particles . (Thesis). Laurentian University. Retrieved from https://zone.biblio.laurentian.ca/handle/10219/2857

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Hmidi, Nuri. “Production and characterization of polystyrene resins containing fine activated carbon particles .” 2017. Thesis, Laurentian University. Accessed December 10, 2019. https://zone.biblio.laurentian.ca/handle/10219/2857.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Hmidi, Nuri. “Production and characterization of polystyrene resins containing fine activated carbon particles .” 2017. Web. 10 Dec 2019.

Vancouver:

Hmidi N. Production and characterization of polystyrene resins containing fine activated carbon particles . [Internet] [Thesis]. Laurentian University; 2017. [cited 2019 Dec 10]. Available from: https://zone.biblio.laurentian.ca/handle/10219/2857.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Hmidi N. Production and characterization of polystyrene resins containing fine activated carbon particles . [Thesis]. Laurentian University; 2017. Available from: https://zone.biblio.laurentian.ca/handle/10219/2857

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Open Access Theses and Dissertations