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Generalised strategy for predicting environmental characteristics of solid mineral wastes : a focus on copper
Includes bibliographical references (p. 221-234).
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| Format: | Thesis |
| Language: | English |
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Department of Chemical Engineering
2014
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| _version_ | 1867613217031716864 |
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| access_status_str | Open Access |
| author | Broadhurst, Jennifer Lee |
| author2 | Petrie, Jim |
| author_browse | Broadhurst, Jennifer Lee Petrie, Jim |
| author_facet | Petrie, Jim Broadhurst, Jennifer Lee |
| author_sort | Broadhurst, Jennifer Lee |
| collection | Thesis |
| description | Includes bibliographical references (p. 221-234). |
| format | Thesis |
| id | oai:open.uct.ac.za:11427/5357 |
| institution | University of Cape Town (South Africa) |
| language | eng |
| last_indexed | 2026-06-10T12:32:37.404Z |
| license_str | Not specified — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository |
| publishDate | 2014 |
| publishDateRange | 2014 |
| publishDateSort | 2014 |
| publisher | Department of Chemical Engineering |
| publisherStr | Department of Chemical Engineering |
| record_format | dspace |
| source_str | UCTD — University of Cape Town Open Access Repository |
| spelling | oai:open.uct.ac.za:11427/5357 Generalised strategy for predicting environmental characteristics of solid mineral wastes : a focus on copper Broadhurst, Jennifer Lee Petrie, Jim Chemical Engineering Includes bibliographical references (p. 221-234). The impacts associated with primary production of metallic and fossil minerals are significant, and these industry sectors are facing increasing pressure to improve environmental performance and contribute to development that is consistent with sustain ability principles. The management of large volumes of solid wastes poses a particular problem, with the potential post-closure impacts and liabilities associated with the prolonged discharge of contaminated leachate from deposits of such wastes remaining of major concern to both regulators and industry. It is only by quantitatively characterising these impacts that we can begin to focus attention backwards in the material chain to the waste generation processes themselves, and thus identify opportunities for process improvements to minimise waste formation and to render wastes environmentally benign. Whilst recognising that knowledge of the key waste properties or characteristics is an essential and integral part of quantitative environmental impact predictions, currently available data pertaining to the characteristics of solid mineral wastes are largely incomplete and inconsistent, and the mechanisms of leachate generation poorly understood. The need to improve the way in which solid mineral wastes are characterised is driven not only by the limitations in terms of current data bases and methodologies for the generation of such. There is also a requirement for a more systematic and rigorous approach, which will ensure that the necessary data and information is integrated into the early decision stages of an environmental performance assessment programme and, ultimately, project life cycle in a time and cost effective manner. It is these shortcomings and challenges that this thesis attempts to address, through the development of a generalised and systematic strategy for predicting the environmentally significant properties of solid mineral wastes on the basis of ore characteristics (waste origins) and generating processes (waste source). The conceptual approach developed within this thesis essentially entails addressing current data gaps and deficiencies through reconciliation of available empirical data with a fundamental understanding of element properties and distribution behaviour in two systematic and consecutive steps. In the first instance, solid waste characteristics are predicted from a consideration of ore type and composition (Le. waste origins), combined with knowledge of the process route from ore to waste (i.e. waste source). Due to their relevance in terms of technical and economic criteria, such as product quality and operational throughput, the behaviour of the targeted metal and major ore components in ores and beneficiation input-output streams is generally fairly well understood. Data gaps and inconsistencies pertaining to these ore components can, for the most part, be adequately addressed on the basis of meaningful generalisations and simple mass balance calculations. In contrast, available data and information relating to compositions of trace and minor co-elements are largely qualitative and inconsistent, and their deportment during the formation and subsequent beneficiation theoretical assessment of the potential distributions, properties and associations of these elements within ore deposits and across process unit operations, based on a fundamental understanding of the governing reaction mechanisms and influencing parameters. The theoretical data and information are subsequently reconciled with available empirical data to generate a comprehensive and quantitative list of potential element distribution factors which, when combined with total mass flow data, results in a first-order inventory of process input-output stream compositions. The second step of the proposed approach entails the prediction of key characteristics relating to criteria of environmental significance. In this step the solid waste constituents, identified and quantified in the first step of the methodology, are screened and ranked in accordance with their hazardous properties and availability for release to the surrounding environment in a disposal scenario. As in the case of predictions of element distributions during ore formation and beneficiation, the theoretical assessment of the potential distribution behaviour of elements from solid wastes is underpinned by a qualitative understanding of the mechanisms and parameters governing their dissolution and attenuation within a waste deposit. Potential environmental risks associated with the various solid waste constituents are subsequently estimated and compared on the basis of their total concentrations, potential environmental availability, and inherent capacity to cause harm. Three separate but inter-related case studies in the context of primary copper production present the key features of the developed approach and related tools. Such features pertain in particular to first order predictions of the chemical and mineralogical compositions of porphyry-type copper sulphide ore deposits; the subsequent distribution of ore components during concentration and smelting of the run-of-mine ores; and the waste constituents of potential environmental significance within a typical flotation tailings impoundment. Apart from addressing data gaps and inconsistencies, these case studies have also served to highlight the links in the ore formation. 2014-07-31T11:12:56Z 2014-07-31T11:12:56Z 2007 Doctoral Thesis Doctoral PhD http://hdl.handle.net/11427/5357 eng application/pdf Department of Chemical Engineering Faculty of Engineering and the Built Environment University of Cape Town |
| spellingShingle | Chemical Engineering Broadhurst, Jennifer Lee Generalised strategy for predicting environmental characteristics of solid mineral wastes : a focus on copper |
| thesis_degree_str | Doctoral |
| title | Generalised strategy for predicting environmental characteristics of solid mineral wastes : a focus on copper |
| title_full | Generalised strategy for predicting environmental characteristics of solid mineral wastes : a focus on copper |
| title_fullStr | Generalised strategy for predicting environmental characteristics of solid mineral wastes : a focus on copper |
| title_full_unstemmed | Generalised strategy for predicting environmental characteristics of solid mineral wastes : a focus on copper |
| title_short | Generalised strategy for predicting environmental characteristics of solid mineral wastes : a focus on copper |
| title_sort | generalised strategy for predicting environmental characteristics of solid mineral wastes a focus on copper |
| topic | Chemical Engineering |
| url | http://hdl.handle.net/11427/5357 |
| work_keys_str_mv | AT broadhurstjenniferlee generalisedstrategyforpredictingenvironmentalcharacteristicsofsolidmineralwastesafocusoncopper |