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Dissertations / Theses on the topic 'Leaching kinetics'

Author: Grafiati

Published: 3 June 2025

Last updated: 31 July 2025

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1

Trejo-Gallardo, Jaime. "Modeling chalcopyrite leaching kinetics." Thesis, University of British Columbia, 2007. http://hdl.handle.net/2429/240.

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Chalcopyrite (CuFeS2) is the most abundant of the copper sulfides and also one of the most refractory for leaching. Several processing routes have been proposed to overcome drawbacks associated with environmental problems related to copper extraction from this mineral. Atmospheric leaching in acidic ferric sulfate is regarded as being particularly attractive over other hydrometallurgical systems. However, the challenge has been to overcome the problem of slow extraction rates due to passivity encountered at high solution potentials in this system. This highlights the need to investigate better

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2

Sililo, Bernard Liswani. "Modelling uranium leaching kinetics." Diss., University of Pretoria, 2016. http://hdl.handle.net/2263/61336.

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The uranium price decline has negatively impacted on the uranium mining industry. This decline in price requires that uranium metallurgical processes be made to operate more efficiently. Some key parameters that influence the dissolution and kinetics of leaching uraninite (one of the main minerals from which uranium can be extracted) are pH, oxidationreduction potential and iron concentration. A good understanding of the effect these parameters have on the leach kinetics would lead to an efficient operation of metallurgical processes. The objective of this work was therefore to investiga

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3

Zaayman, Yolande. "Leaching kinetics of synthetic heazlewoodite / Y. Zaayman." Thesis, North-West University, 2004. http://hdl.handle.net/10394/646.

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The sources of base metals are mainly in the form of oxides or sulphides, of which the sulphides are predominantly present in South Africa. These metals are intergrown platinum group and base metals in the form of alloys and sulphides. In order to produce high grade saleable metals, it is necessary to effectively separate the base metals from the precious metals. By means of a hydrometallurgical process, that is leaching, metals can selectively be extracted from ores. The mechanism of leaching can be described by oxidation-reduction and acid-base reactions. During this study, the leaching of a

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4

Taghi, Nazari Ghazaleh. "Enhancing the kinetics of pyrite catalyzed leaching of chalcopyrite." Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/41937.

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An investigation has been conducted into the kinetics of chalcopyrite leaching in acidic ferric/ferrous sulfate media at atmospheric pressure and low temperature in the presence of pyrite. It has been found that pyrite samples from different sources affect the rate of chalcopyrite leaching differently. Some pyrite samples accelerate the rate significantly while others have little or no influence. The effectiveness of pyrite has a strong correlation with the level of silver occurring in the pyrite. In this study, the use of silver-enhanced pyrite in the Galvanox™ process to improve the extract

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5

Dyson, Devy Alexander William. "Modeling the kinetics of the zinc pressure leaching process - oxidative sphalerite leaching in sulphuric acid media." Thesis, University of British Columbia, 2017. http://hdl.handle.net/2429/63409.

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In the field of hydrometallurgy, the industrial uptake of leaching models has been overlooked partially due to the lack of universal models. A model developed for one plant cannot easily be transferred for the application of a different plant without redesigning the leaching kinetics in the code. The Multiple Convolution Integral (MCI)-based model developed in this thesis has the ability to be universally applied by user-controlled inputs. Chemical reactions can be selected while the modeling software calculates the mass and energy balances. Residence times, operating conditions, and the rate-

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6

Velásquez, Yévenes Lilian de Lourdes. "The kinetics of the dissolution of chalcopyrite in chloride media /." Murdoch University Digital Theses Program, 2009. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20090430.154851.

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7

Angeles, Carlos. "Kinetics of leaching of covellite in ferric-sulfate-sulfuric acid media." Thesis, University of British Columbia, 2015. http://hdl.handle.net/2429/54587.

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Hydrometallurgy methods to extract copper are becoming more frequently applied in modern industry. However, the leaching kinetics for certain minerals like covellite is poorly understood. This thesis investigates the kinetics of covellite leaching in a ferric-sulfate-sulfuric acid media, with an emphasis first placed on the understanding of the effect of the most common variables such as temperature and redox potential. A natural mineral sample of covellite and an ore sample from the Oyu Tolgoi project in Mongolia were obtained for the leaching studies. The leaching temperature was varied fr

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8

Barriga, Vilca Abrahan. "Studies on the curing and leaching kinetics of mixed copper ores." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/44500.

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Heap leaching is a metal extraction process from low grade ores where crushed ore is stacked on an impermeable pad and irrigated from the top with a solution of chemical reagents. An enriched solution containing the targeted metal is collected at the bottom. This technique involves complex chemical/electrochemical reactions and transport processes. Among the main features of this method of extraction include low capital and operative cost, modularity, and relatively high inventory of solutions. The need to optimize a heap operation has led to research studies in order to understand and interp

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9

Filippou, Dimitrios. "Reaction kinetics and reactor modelling of zinc-ferrite hot-acid leaching." Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=41588.

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The main objectives of this Thesis were the determination of the reaction kinetics of the dissolution of zinc-ferrite particles ((Zn$ sb{1-x}$, Fe$ sbsp{x}{2+}$)$ rm Fe sbsp{2}{3+}O sb4$, x $ le$ 0.4) in hot aqueous solutions of sulphuric acid, and the development of a mathematical model for the prediction of the performance of a series of continuous stirred-tank reactors where zinc ferrite is leached.<br>Well-characterised, porous zinc-ferrite particles of industrial origin were subjected to controlled leaching experiments at temperatures close to 373 K in sulphuric acid solutions of concentr

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10

Yalcin, Sezgin. "Modeling Chromium Leaching From Chromite Ore Processing Waste." Master's thesis, METU, 2003. http://etd.lib.metu.edu.tr/upload/4/1053412/index.pdf.

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Chromium has been widely used in many industrial applications. As a result of chromite ore processing, large amounts of chromite ore processing waste (COPW) material that can be classified as hazardous have been produced and released into the environment. Therefore, knowledge of migration behavior and leaching rates of chromium through waste materials and soils are of primary concern for environmentally sound management of land-disposal hazardous wastes. Hask&ouml<br>k (1998) experimentally studied leaching rates of total Cr and Cr(VI) using laboratory columns packed with chromium COPW materia

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11

Chapman, J. T. "The batch and continuous bacterial leaching kinetics of a refractory gold-bearing pyrite concentrate." Master's thesis, University of Cape Town, 1989. http://hdl.handle.net/11427/17706.

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Bibliography: pages 125-136.<br>The recent focus on bacterial leaching as a preoxidation step in the treatment of refractory gold bearing sulphide ores and concentrates, has created the need for kinetic models to adequately describe bacterial leaching reactor performance. This work is a kinetic study of the bacterial leaching of a refractory gold bearing, pyrite concentrate. The study includes the presentation of two mechanistically based, the shrinking particle and propagating pore (Hansford and Drossou, 1986), batch reactor kinetic models. These models are derived for single stage continuous

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12

Gilligan, Rorie. "The extractive metallurgy of brannerite: Leaching kinetics, reaction mechanisms and mineralogical transformations." Thesis, Gilligan, Rorie (2017) The extractive metallurgy of brannerite: Leaching kinetics, reaction mechanisms and mineralogical transformations. PhD thesis, Murdoch University, 2017. https://researchrepository.murdoch.edu.au/id/eprint/36793/.

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Brannerite, ideally UTi2O6 is a refractory uranium mineral found in many uranium and rare earth element ore deposits around the world, including many in Australia. As brannerite is refractory, ores containing brannerite require more intense leaching conditions than typical uranium ores. Brannerite is the most common refractory uranium mineral, and the most important uranium ore mineral after uraninite (UO2) and coffinite (U(SiO4)1-x(OH)4x). Several high-brannerite uranium deposits in Australia remain un-developed, despite being discovered as early as the 1950s. The aim of this study was to

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13

Van, Schalkwyk R. F. "Leaching of Ni-Cu-Fe-S Peirce Smith converter matte : effects of the Fe-endpoint and leaching conditions on kinetics and mineralogy." Thesis, Stellenbosch : Stellenbosch University, 2011. http://hdl.handle.net/10019.1/18069.

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Thesis (MScEng)--Stellenbosch University, 2011.<br>ENGLISH ABSTRACT: In a first stage atmospheric leach at the Lonmin Marikana base metals refinery, nickel-copper-iron-sulphur Peirce Smith converter matte is leached in recycled electrolyte from the electrowinning section. The electrolyte contains sulphuric acid, copper and nickel sulphates, and a small amount of iron sulphate. The converter matte contains mostly nickel, copper and sulphur (typically 48 %, 28 % and 23 %, respectively), but also minor amounts (<5 %) iron and cobalt. The matte also contains platinum group elements (PGEs) an

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14

Yang, Xinbo. "LEACHING CHARACTERISTICS OF RARE EARTH ELEMENTS FROM BITUMINOUS COAL-BASED SOURCES." UKnowledge, 2019. https://uknowledge.uky.edu/mng_etds/49.

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The demand for rare earth elements (REEs) has increased over the last decade due to applications in high technology devices including those in the defense industry. The recovery of REEs from primary sources such as rare earth minerals are viable using physical separations followed by chemical processing. However, weak market values and environmental concerns have limited the viability of such operations. On the other hand, REE recovery from secondary sources such as apatite ore, bauxite waste, and waste recycling, provides an opportunity to take advantage of a resource that does not require mi

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15

Fowler, Terry-Ann. "Kinetics of the ferric sulphate leaching of sphalerite and sphalerite/pyrite mixtures : a study of the chemical leaching of base metal minerals under conditions similar to that of bio-leaching by thiobacilli." Master's thesis, University of Cape Town, 1996. http://hdl.handle.net/11427/21699.

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Bibliography: pages 98-105.<br>The work presented in this dissertation is an investigation of-the ferric leaching of zinc from sphalerite. A further aspect of this study was an investigation of the influence of pyrite on the dissolution rate of sphalerite due to possible galvanic interactions. This study is one component of a larger study of the sub-processes involved in the bioleaching of sulphide minerals in which the ferric leaching of the sulphide mineral is assumed to be a chemical step with the bacteria oxidising ferrous iron to ferric iron and elemental sulphur, if formed, to sulphate.

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16

Liaw, Sui Boon. "Leaching of inorganic and organic matter from biomass and biochars under various conditions: equilibrium, kinetics and implications." Thesis, Curtin University, 2015. http://hdl.handle.net/20.500.11937/2059.

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This thesis investigates into the leaching phenomena in various biomass thermochemical processes. For biomass water leaching, the leachate is acidic and can interact with biomass. A method has therefore been devised for quantifying water-soluble inorganic species in biomass. For biochar leaching, partial steam gasification of biochar at low conversions is a good strategy to facilitate nutrients recycling. For biomass leaching in hot-compressed water, substantial leaching of inorganic species takes place during the hydrolysis of saccharides.

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17

Nikkhou, Fatemeh. "Formation mechanisms of surface passivating phases and their impact on the leaching kinetics of sphalerite (ZnS) and galena (PbS)." Thesis, Nikkhou, Fatemeh (2021) Formation mechanisms of surface passivating phases and their impact on the leaching kinetics of sphalerite (ZnS) and galena (PbS). PhD thesis, Murdoch University, 2021. https://researchrepository.murdoch.edu.au/id/eprint/61036/.

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Sphalerite (ZnS) and galena (PbS) are the primary sources of zinc and lead, respectively. They often coexist in ore deposits. Extraction of zinc and lead is traditionally achieved by high-temperature roasting and smelting processes in which gaseous SO2 is produced, requiring expensive treatment. Hydrometallurgical leaching such as heap leaching and in situ leaching are environmentally more sustainable due to higher energy efficiency and no release of SO2, but slow leaching rate is the main challenge restricting their wide applications. The leaching rate is significantly affected by the formati

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18

Yue, Guikuan. "Speciation of the sulfuric acid-ferric sulfate-ferrous sulfate-water system and its application to chalcopyrite leaching kinetics up to 150 ºC." Thesis, University of British Columbia, 2015. http://hdl.handle.net/2429/52467.

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Hydrometallurgical oxidation methods are increasingly being considered for the extraction of Cu from chalcopyrite. However, the kinetics of cathodic ferric ion reduction are poorly understood. This thesis investigates the kinetics of cathodic ferric ion reduction on chalcopyrite and its influence on the leaching process in acidic iron sulfate solution, with an emphasis first placed on the development of a speciation model for the H₂SO₄-Fe₂(SO₄)₃-FeSO₄-H₂O system from 25°C-150°C. Speciation results show that most Fe(III) is distributed as complexes or precipitates and the free Fe³+ accounts fo

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19

com, seanzhang06@hotmail, and Xin-min Zhang. "The dissolution of gold colloids in aqueous thiosulfate solutions." Murdoch University, 2008. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20090807.121135.

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The kinetics of the dissolution of gold and silver colloids in ammoniacal thiosulfate solutions has been studied using oxygen, copper(II) or oxygenated copper(II) as oxidants at pH 9 - 11 and temperature 22oC to 48oC. The effects of the concentration of the main reagents such as copper(II), ammonia and thiosulfate as well as various background reagents have been investigated. Gold and silver colloids have characteristic absorption peaks at 530 nm and 620 nm respectively. Thus, the extent of gold or silver dissolution in different lixiviant systems was monitored using an ultraviolet-visible spe

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20

Ramunno, Franco Alves Lavacchini. "Estudo cinético da lixiviação de metais de placas de circuito impresso obsoletas." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/3/3137/tde-07072016-152302/.

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O processo tradicional de recuperação de metais de resíduos de equipamentos eletroeletrônicos (REEE) geralmente envolve processamento pirometalúrgico. Entretanto, o uso desta tecnologia para processar placas de circuito impresso (PCI) obsoletas pode levar à liberação de dioxinas e furanos, devido à decomposição térmica de retardantes de chama e resinas poliméricas presentes no substrato das placas. Portanto, este trabalho propõe uma rota hidrometalúrgica para recuperação de metais. O comportamento dos metais, com destaque para cobre, zinco e níquel, durante a lixiviação ácida, foi estudado em

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21

Dickson, Okechukwu Vincent. "Study of the thermodynamic-kinetic coupling in the hydrometallurgical extraction of nickel and cobalt in a High-Pressure Acid Leaching (HPAL) autoclave." Electronic Thesis or Diss., Ecole nationale des Mines d'Albi-Carmaux, 2025. http://www.theses.fr/2025EMAC0004.

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La volonté politique de réduire l'utilisation des combustibles fossiles et de remplacer les véhicules actuels par des véhicules électriques implique l'essor du marché des batteries. Afin de garantir une performance optimale de ces batteries, il est essentiel de contrôler la pureté des métaux produits dont les éléments Nickel (Ni) et Cobalt (Co) en font partie. En Nouvelle-Calédonie, les gisements latéritiques représentent 20 à 25 % des ressources mondiales de nickel. La société Prony Resources New Caledonia (Prony Resources NC) y exploite un procédé hydrométallurgique pour produire un co-préci

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22

Kameoka, Fernando. "Reciclagem de resíduos eletroeletrônicos: um estudo cinético da lixiviação ácida de ferro de placas de circuito impresso de microcomputadores." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/3/3137/tde-07072016-144159/.

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O aumento no consumo mundial de novos aparelhos eletroeletrônicos aliado à redução no tempo de vida útil destes equipamentos tem como principal consequência ao meio ambiente a geração de resíduos. No Brasil, com a instituição da Política Nacional de Resíduos Sólidos, criou-se a obrigatoriedade legal da responsabilidade dos fabricantes pela logística reversa dos equipamentos eletroeletrônicos, incentivando pesquisas para o desenvolvimento dos métodos de reciclagem e tratamento dos materiais descartados. O processo de lixiviação foi avaliado como alternativa à etapa de separação magnética presen

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23

Munkondya, Ferguson Mukozoke. "Kinetic modelling of leaching." Thesis, Imperial College London, 1989. http://hdl.handle.net/10044/1/47583.

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24

Birgersson, Henrik. "Development and Assessment of Regeneration Methods for Commercial Automotive Three-Way Catalysts." Doctoral thesis, Stockholm, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3931.

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25

Fernández, Renna Ana Inés. "Procedimiento para la obtención de hidromagnesita: estudio cinético." Doctoral thesis, Universitat de Barcelona, 2000. http://hdl.handle.net/10803/667560.

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El procedimiento que se estudia para la obtención de carbonato básico de magnesio consta de dos etapas: la lixiviación en CO2 de una pulpa que contienen MgO, y la precipitación del producto utilizando la solución de bicarbonato de magnesio de la etapa anterior y MgO como agente precipitante. Se realiza el estudio cinético de ambas etapas separadamente. En la primera etapa, la etapa de lixiviación se forma una solución de bicarbonato de magnesio y, según las condiciones experimentales, un precipitado de hidroxicarbonato de magnesio. En ausencia de precipitado, el proceso de carbonatación cumpl

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26

Laubscher, Sydney. "MANGANESE UPTAKE IN RED MAPLE TREES IN RESPONSE TO MINERAL DISSOLUTION RATES IN SOIL." Kent State University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=kent1574431912056187.

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27

Close, Thomas Jr (Thomas Charles). "Kinetic analysis of leaching reactions in multi-component mineral systems." Thesis, Massachusetts Institute of Technology, 2021. https://hdl.handle.net/1721.1/130666.

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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Chemical Engineering, February, 2021<br>Cataloged from the official PDF of thesis.<br>Includes bibliographical references (pages 167-177).<br>The rational design of reactive systems requires the use of kinetic models of system behavior. However, the development of such models for multicomponent systems is complicated by conditions of mutual interference in determining reaction rates. Addressing this shortcoming for mineral systems requires developing methods to solve the fundamental problem of identity and resolve the partiti

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GUEVARA, LILIAN ROCIO ZEGARRA. "POTENTIAL PREDICTION OF ACID MINE DRAINAGE EMPLOYING LEACHING COLUMN KINETIC METHOD." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2007. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=10536@1.

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CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO<br>A drenagem ácida de minas (DAM) é um problema ambiental capaz de comprometer a qualidade dos recursos hídricos, que decorre da oxidação de sulfetos. A adoção de medidas corretivas e/ou preventivas dependerá do programa de predição escolhido, este geralmente inclui testes do potencial de geração de acidez (método estático), e da velocidade com que ocorre o processo (método cinético). No presente trabalho avaliou-se o potencial de geração de DAM usando o teste de Balanço Ácido Base Modificada (BABM), e monitorou-se a qualidad

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Jiang, Mofen. "The Chemical and kinetic mechanism for leaching of chrysocolla by sulfuric acid." Thesis, The University of Arizona, 1992. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu_e9791_1992_610_sip1_w.pdf&type=application/pdf.

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Behum, Paul Thomas. "LABORATORY AND FIELD INVESTIGATIONS OF COAL AND COAL PROCESSING WASTE - SIMULATION OF PRACTICES THAT MINIMIZE SULFATE AND CHLORIDE." OpenSIUC, 2016. https://opensiuc.lib.siu.edu/dissertations/1273.

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The potential for mobilization of SO4 and Cl from coal stockpiles and coal processing waste and refuse (waste rock) disposal areas to the receiving streams and groundwater is an environmental concern and proper management practices are necessary to minimize the impact of these discharges. In an effort to characterize the long-term environmental impact of weathering in from both a typical coal stockpile and coal waste disposal areas a series of laboratory- scale and field-scale kinetic tests were performed with the ultimate goal of improving both coal and coal waste management at coal mines in

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31

Poltorak, Sergej. "Amperometrinio biojutiklio su chemiškai modifikuotu elektrodu vykstančių reakcijos-difuzijos procesų kompiuterinis modeliavimas ir tyrimas." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2014. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2011~D_20140627_170922-37372.

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Magistrinio darbo tikslas yra sukurti kompiuterinį amperometrinio biojutiklio su chemiškai modifikuotu elektrodu modelį ir ištirti jo savybes. Modelis papildo egzistuojančius modelius mediatoriaus sluoksniu. Mediatoriaus koncentracija sluoksnyje nėra konstanta, tirpsta biojutiklio veikimo eigoje. Darbe apžvelgiama medžiaga apie amperometrinius biojutiklius, biojutiklio modeliavimo aspektus, mediatoriaus tirpimo priežastis ir veikimo principus. Vėliau suformuluojamas pasirinkto biojutiklio matematinis modelis. Matematiniame modelyje pateikiamos diferencialinės lygtys su dalinėmis išvestinėmis,

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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." Thesis, Curtin University, 1997. http://hdl.handle.net/20.500.11937/2030.

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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 le

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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." Curtin University of Technology, School of Applied Chemistry, 1997. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=11442.

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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 le

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34

Brouard, Christine. "Contribution à l'étude de la rétention de phénylurées (herbicides) par des adsorbants modèles et des sols." Angers, 1995. http://www.theses.fr/1995ANGE0006.

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Notre objectif était d'étudier la rétention d'herbicides de la famille des phenylurées sur des adsorbants minéraux et dans le sol. Les molécules retenues sont le chloroxuron, le chlortoluron, le metobromuron, l'isoproturon et le difenoxuron. Les adsorbants utilises sont la celite, le florisil, l'alumine, le carbonate et le sulfate de calcium. Les sols étudiés sont un sol limoneux-argileux et un sol limoneux-sableux. Nous poursuivons le double but analytique et environnemental d'améliorer les étapes de purification par chromatographie d'adsorption d'extraits en vue de l'analyse de résidus, et d

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Haddadin, Jamal. "Études microbiologiques et cinétiques de la lixiviation bactérienne en réacteurs : effet de différents paramètres physico-chimiques, développement d'un procédé en réacteurs air-lift et lit-fluidisé et application à l'extraction de l'antimoine." Vandoeuvre-les-Nancy, INPL, 1995. http://www.theses.fr/1995INPL063N.

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La lixiviation bactérienne est l'application biotechnologique la plus importante dans l'industrie métallurgique, celle-ci est utilisée pour la récupération des métaux par lessivage, utilisant les capacités que possèdent certains micro-organismes à solubiliser les métaux. Ce travail est divisé en quatre sections: premièrement, nous avons identifié la composition microbiologique de la culture mixte en notre possession. Cette culture mixte est composée de trois populations bactériennes. Deuxièmement, nous avons étudié l'influence de certains paramètres physico-chimiques tels que le pH, la tempéra

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Barkle, Gregory Francis. "The fate of carbon and nitrogen from an organic effluent irrigated onto soil : process studies, model development and testing." Lincoln University, 2001. http://hdl.handle.net/10182/1959.

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The fate of the carbon and nitrogen in dairy farm effluent (DFE) applied onto soil was investigated through laboratory experiments and field lysimeter studies. They resulted in the development and testing of a complex carbon (C) and nitrogen (N) simulation model (CaNS-Eff) of the soil-plant-microbial system. To minimise the risk of contamination of surface waters, regulatory authorities in New Zealand promote irrigation onto land as the preferred treatment method for DFE. The allowable annual loading rates for DFE, as defined in statutory regional plans are based on annual N balance calculati

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COSTA, GIULIA. "Accelerated carbonation of minerals and industrial residues for carbon dioxide storage." Doctoral thesis, Università degli Studi di Roma "Tor Vergata", 2009. http://hdl.handle.net/2108/1003.

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Le reazioni di carbonatazione di specifiche tipologie di minerali e materiali di diversa origine, come ad esempio malte cementizie o calce, costituiscono un ben noto processo naturale che produce una serie di significativi effetti sugli stessi materiali alcalini, ed in particolare: lo stoccaggio di CO2 mediante la formazione di una fase carbonatica solida e termodinamicamente stabile, la riduzione del pH e modifiche del comportamento alla lisciviazione del materiale, oltre alla variazione di alcune proprietà fisiche e meccaniche. Dato che le cinetiche di reazione sono in genere molto lente in

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Bolorunduro, Samuel Adewale. "Kinetics of leaching of chalcocite in acid ferric sulfate media : chemical and bacterial leaching." Thesis, 1999. http://hdl.handle.net/2429/9400.

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The lack of a clear understanding of the rate of chalcocite (Cu₂S) and covellite (CuS) leaching in the presence and absence of bacteria has been a limitation on the optimization of hydrometallurgical processes for the recovery of copper from these minerals. In order to enhance the performance of heaps and other leaching processes for these minerals, there is a need to examine the conditions required to improve the rate of leaching. Such an investigation will produce a particle scale model (for the intrinsic rate of leaching), which can be combined with a heap scale model to form a compre

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Chen, Alan Airong. "Kinetics of leaching galena concentrates with ferric fluosilicate solution." Thesis, 1992. http://hdl.handle.net/2429/3307.

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A new hydrometallurgical leaching process, which dissolves galena concentrates with acidified ferric fluosilicate solution, has been investigated for the selective extraction of lead and zinc from the galena concentrates. The process of leaching galena concentrates avoids the generation of sulfur dioxide and lead dust emissions and is capable of treating complex sulfide and low-grade flotation concentrates. The leaching of Pine Point galena concentrates by ferric fluosilicate solutions was studied under various experimental conditions in the temperature range 20 to 95°C. Temperature had

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YA-HUEIKANG and 康雅惠. "Kinetics study on the acid-base leaching of clay minerals." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/65549141256706019704.

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碩士<br>國立成功大學<br>資源工程學系碩博士班<br>98<br>The results of a dissolution kinetics of clay minerals (Ca-Montmorillonite, Na-Montmorillonite, Fisher bentonite, Mica, Kaolinite, Attapulgite and Talc) and silt (Quartz,Illite,Chlorite)in acid and base were presented . Effect of stirring speed, acid and base type, reaction temperature,and the concentration of acid and base on Al3+ dissolution rate and activation energy were determined . The results obtains show that extraction as a function of acid concentration, temperature and time. It was determined that stirring speed did not significantly affect Al3+ e

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Williams, Lonnie Dwayne. "Kinetics of leaching and binding of fumonisin B₁ in soil microcosms." 2002. http://purl.galileo.usg.edu/uga%5Fetd/williams%5Flonnie%5Fd%5F200205%5Fms.

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"Kinetics of leaching of a low grade matter in ferric sulphate solution." Thesis, 2015. http://hdl.handle.net/10539/17196.

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Tshilombo, Alain Fuamba. "Mechanism and kinetics of chalcopyrite passivation and depassivation during ferric and microbial leaching." Thesis, 2006. http://hdl.handle.net/2429/18503.

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Chalcopyrite is known to be recalcitrant to conventional hydrometallurgical and biohydrometallurgical processes. Formation of passive layers on the chalcopyrite surface results in slow and incomplete leaching. The nature of how these passive layers are formed is the subject of much controversy. The most likely explanation is the formation of polysulphide compounds or copper-rich intermediate products on the chalcopyrite surface. The formation of these products depends mainly on temperature and solution potential. Based on these observations, electrochemical techniques were used to study the be

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Conradie, Petrus Jacobus. "An electrochemical model for the leaching kinetics of gold ore in cyanide solutions." Thesis, 2015. http://hdl.handle.net/10539/16962.

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This project consisted of a literature and a laboratory study to investigate the applicability of an electrochemical model, to the leaching kinetics of gold ore. The procedure was to get an approximate measurement of the gold surface potential and then, to use only this potential and an area term in a two parameter rate expression. The potential measurements in a pulp, with a gold and gold-silver electrode, were attempted but, the electrodes became passive. The results showed that the rate controlling mechanism was a combination of the rate of both oxygen and cyanide diffusion and it w

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Huberts, Robert. "Application of electrochemical kinetics to elucidate the leaching mechanism in the bio-oxidation of a synthetic nickel sulphide." Thesis, 2015. http://hdl.handle.net/10539/16901.

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The importance of the direct and indirect mechanisms in the bacterial leaching of a synthetic nickel sulphide is investigated using an electrochemical leaching model. Sterile controls runs, in which only ferric leaching took place, are compared with runs in the presence of an active, adapted bacterial culture. The direct mechanism occurs when bacteria attach to the sulphide mineral and catalyze the oxidation of the mineral, presumably with enzymes (biological catalysts). No evidence was found of the direct mechanism, in fact ferric leaching appeared to be inhibited as the bacterial

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KUO, CHING-HUI, and 郭清輝. "The fundamental study of leaching process and kinetics with waste CIGS thin film solar cells." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/pa5546.

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碩士<br>大漢技術學院<br>土木工程與環境資源管理研究所<br>105<br>In this study, the waste CIGS thin film solar cell glass was used as the raw material for the preparation of acid impregnated, and sulfuric acid was used as the impregnant to impregnate the CIGS thin film solar cell membrane glass with different acid concentration, different speed, different liquid-solid ratio and different temperature for 1 hour , And calculate the dissolution rate of copper, indium and zinc in solar thin film batteries. In this study, the dissolution rate of copper was increased by acid dipping with 2N sulfuric acid at a liquid-solid

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Ouyang, Min. "The study of the kinetics of gold leaching in the ammonium thiosulfate in the presence of copper." Thesis, 2001. http://hdl.handle.net/2429/11581.

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The kinetics of gold leaching in ammonium thiosulfate solution in the presence of copper have been studied by electrochemical polarization and direct rotating disk leaching methods. The effects of pH, temperature, rotating velocity and the concentrations of different reagents on the gold leaching rate have been investigated. It was found that the anodic oxidation of gold in ammonium thiosulfate solution is complex. Ammonia, thiosulfate and copper species all affect the anodic process. The anodic process is under surface reaction control. The above species plus oxygen are involved in the

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Flatt, James R. (James Robert). "The kinetics of pyrite and elemental sulfur reactions during nitric acid pre-oxidation of refractory gold ores / by James R. Flatt." Thesis, 1996. http://hdl.handle.net/2440/18915.

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Bibliography: leaves 192-193.<br>ix, 214, ix leaves : ill. ; 30 cm.<br>The focus of the thesis is to investigate the fundamental kinetics of the pyrite-nitric acid system. Particular attention is paid to the formation and oxidation of elemental sulfur. The study aims to elucidate the chemistry of the sulfide oxidation and of elemental sulfur formation and oxidation.<br>Thesis (Ph.D.)--University of Adelaide, Dept. of Chemical Engineering, 1997?

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Flatt, James R. (James Robert). "The kinetics of pyrite and elemental sulfur reactions during nitric acid pre-oxidation of refractory gold ores / by James R. Flatt." 1996. http://hdl.handle.net/2440/18915.

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Bibliography: leaves 192-193.<br>ix, 214, ix leaves : ill. ; 30 cm.<br>Title page, contents and abstract only. The complete thesis in print form is available from the University Library.<br>The focus of the thesis is to investigate the fundamental kinetics of the pyrite-nitric acid system. Particular attention is paid to the formation and oxidation of elemental sulfur. The study aims to elucidate the chemistry of the sulfide oxidation and of elemental sulfur formation and oxidation.<br>Thesis (Ph.D.)--University of Adelaide, Dept. of Chemical Engineering, 1997?

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Crundwell, Frank Kenneth. "Kinetics of the leaching of sphalerite in acidic ferric sulphate media in the presence and absence of oxygen." Thesis, 2015. http://hdl.handle.net/10539/16555.

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