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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Estudo comparativo de amostragem em furos de sondagem e galerias para pesquisa de cassiterita no Pegmatito Xupé - Monte Alegre de Goias (GO)

Tarcisio José Montanheiro 27 May 1994 (has links)
Este trabalho, complementado por documentação geológica da região do depósito e por uma revisão não só dos métodos clássicos de avaliação de reservas como também dos conceitos e técnicas de amostragem na pesquisa mineral, apresenta os resultados de um estudo comparativo de amostragem em furos de sondagem e em galerias para pesquisa de cassiterita no Pegmatito Xupé, em Monte Alegre de Goiás, GO. Os corpos pegmatíticos, por exibirem grande variabilidade natural dificultam os processos de amostragem e pesquisa, que, não obstante isso, são de vital importância, quando se pensa no aproveitamento industrial dessa fonte de vários metais raros. Os estudos mostram existir grande diferença de teores médios de estanho nos furos de sondagem e em galeria: basta, para isso, observar a redução constante da variância em face da relação fundamental da amostragem: volume x variância. Para corpos pegmatíticos constatou-se que a amostragem de grande massa é a mais indicada, e os resultados analíticos de furos de sondagem devem ser vistos apenas como valores indicativos, mas importantes, numa rápida visualização tridimensional do corpo mineral. Com os dados levantados no inventário da pesquisa mineral, a avaliação de reservas do Pegmatito Xupé, pelo método dos perfis padrão, é da ordem de 415000 m³ de minério com 1695 g de Sn/m³ e 53 g de \'Ta IND. 2\'\'O IND. 5\'/m³. / This paper presents the results of a comparative statistic study between drill hole sampling and drift\'s channel sampling results carried out during the underground exploration and ore reserve evaluation in the Xupé pegmatite - Monte Alegre de Goiás - State of Goiás. The complete geological documentation available in the area, a revision of classical methods for ore reserve estimation and a revision of concepts and techniques of sampling are also presented in this dissertation. The pegmatite ore bodies usually exhibit a large natural grade variability. In this way the sampling procedures are not easy to acomplish being of capital importance for the appropriate evaluation and industrial use as a source of rare metals. When both drill hole and drift Sn grade results are compared, large differences of the average grade are noticed. This is true because of the inverse correlation between variance and sample volume which keeps the fundamental relation of sampling: volume x variance = constant. It is concluded that bulk sampling is most indicated for Sn pegmatite ore bodies evaluation and the grade values obtnined from drill cores should be used to delineate the tridimensional geometry and ore limits. Measured and indicated reserves are of the order of 415000 m³, with 1695 g Sn/m³ and 53 g \'Ta IND. 2\'\'O IND. 5\'/m³.
22

The abandonment of landownership: a proposed model for regulated exit

Cramer, Richard Henry 19 January 2021 (has links)
The question whether it is possible to abandon landownership is unresolved in South African law. The subject has only rarely been the subject of attention by scholars, with legislation and existing case law providing little in the way of clear guidance. This lack of clarity is obviously not ideal. In South Africa landowners may find themselves burdened with the ownership of land which has accrued a negative value. This thesis seeks to engage with the question on a theoretical level, including to provide answers to practical problems in the South African landownership context. Ultimately two primary questions must be answered: 1. Is the abandonment of landownership possible in the South African legal framework? 2. Should the abandonment of landownership be permitted, and if so, under what circumstances? The first question is evaluated in light of existing common-law principles, case law, as well as legislation such as the Deeds Registries Act 47 of 1937. However, the second question will be the primary focus of the thesis. Through the lens of the socialobligation norm of property as conceptualised by Gregory Alexander, as well as comparative studies of Swiss and Scots law, the thesis explores the viability of a right to abandon landownership in South African law. The thesis argues that the abandonment of landownership in South Africa is not possible in the prevailing legal framework. Furthermore, an unrestricted right to abandon is not viable in the South African socio-economic context. However, landowners who find themselves burdened with land which has accrued a negative value for which they are not at fault may require some form of regulated exit from that ownership. The thesis makes suggestions for legislative law reform in this regard, to provide balance between the interests of landowners and the wider community.
23

The 'formalisation dilemma' of artisanal and small-scale mining: an analysis with reference to the Democratic Republic of the Congo

Pein, Rebecca-Lee 24 June 2022 (has links)
This thesis contributes to the discussion about the impact and dynamics of the informal Artisanal and Small-scale Mining (ASM) sector in sub-Saharan Africa, focusing on the case of the Democratic Republic of Congo (DRC). The debate around ASM's informality in sub-Saharan Africa is increasingly gathering momentum in the region's development and donor dialogues. A unique sector populated by a heterogenous group of people, ASM has in recent years expanded rapidly around the globe. More and more countries are recognising the economic importance of the ASM sector, particularly in sub-Saharan Africa, forcing many donors and policymakers to ‘reconsider' development strategies for ASM. With the growth in ASM, many countries have endeavoured to formalise their ASM sectors in hope of bringing ASM activities into the formal domain and in turn mitigating the negative consequences which flow therefrom. Despite these ASM-formalisation efforts, governments continue to face numerous obstacles along the way, with many of the artisanal miners continuing to operate illegally. The case study of the DRC provides an informative understanding of ASM's informality in sub-Saharan Africa and depicts the issues experienced by a country attempting to formalise its ASM sector. The DRC is one such country that has implemented legislation and introduced numerous initiatives to help bring its ASM sector into the formal domain. The unfortunate reality is that the country seems to be trapped in what this thesis terms the ‘formalisation dilemma', as thousands of artisanal miners continue to operate outside of the legal framework; a phenomenon which is not unique to the DRC experience. To date, most of the AMS-formalisation undertakings and support in sub-Saharan Africa have focused on the financial and technical aspects of the sector, with emphasis being placed on controlling ASM activities ad hoc, instead of proactively engaging and supporting ASM operations. This thesis examines the correlation between the rise in ASM activities and state or institutional failure and concludes by recommending various solutions to this so-called ‘formalisation dilemma'.
24

Consultation and consent under the MPRDA and the IPILRA: a legal analysis of the decision-making practices of customary communities in South Africa

Ntsanwisi, Fezeka 08 March 2022 (has links)
Under the Mineral and Petroleum Resources Development Act 28 of 2002 (MPRDA), the State, as custodian of mineral resources, has the authority to grant rights to minerals and permits in favour of applicants that satisfy the requirements of the prescribed application procedures. Applicants for rights to minerals and permits must consult meaningfully with landowners and lawful occupiers, although the MPRDA itself does not require the latter's prior consent. The Interim Protection of Informal Land Rights Act 31 of 1996 (IPILRA), by contrast, requires prior consent when persons are deprived of their informal rights to land. In South Africa, communities that occupy land under customary land tenure are recognised as lawful occupiers that have informal rights to land. The occupation of land by customary communities and the applicant's interest to exploit mineral resources creates competing rights and interests between these two parties, namely: a right to consultation and a right of access to land. This minor dissertation aims to analyse the impact that the current statutory formulation of the requirements of consultation and consent has on the informal rights to land held by customary communities. This aim translates into two sub-inquiries: How do the statutorily required processes of consultation and consent embodied in the MPRDA and the IPILRA protect the informal rights to land held by customary communities? Furthermore, do the statutorily required processes of consultation and consent meaningfully engage with the existing decision-making practices of customary communities? These issues are considered in light of the elevated status that customary law enjoys under South African law and the Constitution's aspiration to reform racially discriminatory landholding systems. The dissertation argues that the statutorily required processes of consultation and consent inadequately engage with the existing decision-making practices of customary communities. It offers insight on how engagement with the existing decision-making practices, and with the Free, Prior and Informed Consent principle, can better accommodate and protect the rights and interests of customary communities that are affected by prospecting and mining operations.
25

Towards a Framework for Regulating the Sustainability of Mine Hospitals: A Legal Perspective

Kabuzi, Doreen Nabisere 15 September 2020 (has links)
Mining sites are often located in rural and remote communities where healthcare services are either unaffordable or unavailable to mine employees. To address this problem, mining companies may elect to establish and manage mine hospitals to provide vital healthcare services to their employees and the surrounding communities. Mining companies often have the financial capacity to establish state-of-the-art facilities with medical equipment and technology required for the diagnosis and treatment of diseases, including diseases prevalent in the mining industry. The role of mine hospitals extends beyond the development of health infrastructure and the provision of healthcare services. Mine hospitals contribute to the economic development of mine-affected communities. Mine hospitals create employment opportunities that increase disposable income in mine-affected communities and boost local economic activities. Additionally, mining companies can promote local procurement by purchasing goods and services needed for their mine hospitals from local suppliers. Notwithstanding the positive socio-economic impacts of mine hospitals in mineaffected communities, the closure or ownership and management transfer of mine hospitals can have adverse effects on mine-affected communities. These adverse effects include the poor management of mine hospitals, the termination or suspension of healthcare services, and job losses. Therefore, responsible mine hospital closure and transfer practices must be implemented by mining companies to prevent or minimise these adverse effects. This minor dissertation examines the history, role, and function of mine hospitals in mine-affected communities in South Africa. It evaluates the positive and negative (specifically mine hospital closures and ownership and management transfers) impacts of mine hospitals on mine-affected communities. Based on the role and function of mine hospitals and their impacts on mine-affected communities, the dissertation recommends that certain aspects of mine hospitals are governed differently from general private hospitals and standard workplace-based systems. It proposes specific legislative requirements and procedures for the establishment, ownership and management transfer; and closure of mine hospitals. Additionally, the dissertation makes recommendations on the roles of the government, mining companies, and mine-affected communities in the establishment, transfer, and closure processes.
26

Överberg vid tillredning - En studie vid LKABs underjordsgruva i Malmberget

Oldhammer, Daniel January 2017 (has links)
No description available.
27

Panorama da indústria de água mineral na região metropolitana do Recife

ASSIS, Artur Angelo Alcântara de 31 January 2012 (has links)
Made available in DSpace on 2014-06-12T17:37:07Z (GMT). No. of bitstreams: 2 arquivo9434_1.pdf: 1712434 bytes, checksum: 6d17b3fafa45ff8f5a60fc873e13640c (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2012 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Este estudo produz um panorama da indústria da água mineral na Região Metropolitana do Recife (RMR), registrando seus impactos econômicos, assim como o cumprimento da legislação em vigor. Outro aspecto identificado e avaliado é a qualidade do produto consumido pelos pernambucanos a partir dos parâmetros estabelecidos pelo Ministério da Saúde. A revisão bibliográfica apresenta os aspectos científicos e técnicos necessários para o aproveitamento da água mineral e o processo de legalização da indústria. A pesquisa envolveu visitas técnicas ao Departamento Nacional de Produção Mineral DNPM, para coletar os dados indispensáveis a este estudo; e aos complexos industriais da RMR, para conhecimento presencial do processo produtivo. O estudo descritivo foi adotado a fim de identificar os tipos de captações, volume comercializado, empregos gerados, custo operacional, lucro líquido inicial, características físico-químicas dos produtos envasados nos complexos em atividade na RMR. Pernambuco é o segundo estado em volume de produção de água mineral no Brasil, o cruzamento das informações obtidas no estudo das captações da RMR torna possível afirmar que o envase e comercialização de água mineral na Região são atividades de alta lucratividade, sazonal, porém perene, de baixo risco com margem para expansão. No aspecto físico-químico, que determina a qualidade do produto, os dados coletados mostram a necessidade de maior fiscalização dos órgãos competentes para exigência do cumprimento das normas como os limites recomendados para o pH que é atendido por apenas 14% das indústrias avaliadas. Este estudo pode contribuir para o maior conhecimento e aperfeiçoamento das práticas e das Leis de monitoramento e análise do processo de industrialização e comercialização da água mineral em Pernambuco
28

Deformationsmätningar av förstärkningsbågar i biotitområden i LKAB:s gruva i Malmberget

Ylmefors, Andreas January 2019 (has links)
I takt med att gruvbrytningen går djupare förändras förutsättningarna för malmbrytning. Med djupet ökar de vertikala bergspänningarna och beroende på brytningsmetod kan även de horisontella bergspänningarna öka. Geologin förändras också genom att vissa bergarter och mineral kan bli ovanligare på djupare nivåer och andra kan bli vanligare. Flera andra omständigheter kan förändras i takt med att mer bergmaterial tas ut. Dessa faktorer ställer höga krav på en fungerande bergförstärkning för att säkerställa personalens säkerhet och för att göra det möjligt att uppnå den planerade produktionskapaciteten. Kunskap om bergförstärkningens egenskaper är därför mycket viktig. Dess styrkor och svagheter måste kännas till. Detsamma gäller bergförstärkningens livslängd. I LKAB:s underjordsgruva i Malmberget har vissa malmkroppar länge haft problem med förekomst av biotitskiffer i malmkontakten. Biotit är ett anisotropt mineral som har mycket dålig hållfasthet. Det orsakar problem för ortstabiliteten, speciellt i området Alliansen – Hoppet – Prinzsköld där vissa ortar har blivit kraftigt deformerade, eller till och med rasat ihop. För att hantera stabilitetsproblemen i området testas en ny variant av bergförstärkning. Förstärkningsbågar bestående av nätkorgar av stål täcks med fiberarmerad sprutbetong och minst 7 meter långa wirebultar installeras genom dessa. Eftersom det är en ny bergförstärkningsmetod är inte dess hållbarhet och deformationsbeständighet dokumenterad. I detta arbete mäts deformationerna i några utvalda förstärkningsbågar i syfte att undersöka hur deformationerna utbildas och vilka samband de har med sprängningar, geologi, seismisk aktivitet och den omgivande bergmassans deformationer. Resultatet av arbetet visar att det är en mycket komplex situation med många variabler som troligen samverkar för att orsaka deformationerna. För att övervaka den nya förstärkningen rekommendera
29

Flotation of Yxsjöberg historical tungsten ore tailings

Gan, Princess Rochelle January 2019 (has links)
Tailings dams, due to their sheer size and metal content, pose safety and environmental hazards. The Småltjarnen repository, which hosts material from the largest known tungsten mineralization in Sweden named the Yxsjöberg deposit, is estimated to contain 2.2 million tons of material from previous operations when recovery rates of scheelite, chalcopyrite, and fluorite were low. The repository is also observed to contain at least four of the listed critical raw materials by the European Commission in 2017, namely tungsten, fluorite, beryllium, and bismuth. The amenability of this tailings repository as secondary sources for valuable minerals and metals supports the Raw Material Initiative and the drive of the European Union towards a more circular economy. This masters thesis is part of the REMinE (Improve Resource Efficiency and Minimize Environmental Footprint) project that aims to evaluate the amenability of historical mining waste for re-processing from the technical, economical, and environmental perspectives. The study focuses on work package 3 of the project: Identification of new processing methods for mine waste. Previous work on this repository includes geochemical characterization and physical separation through magnetic and gravity separation tests. Since scheelite, the main mineral of the deposit, is commonly recovered through combinations of gravity separation and flotation methods, it is imperative to investigate the response of the material to flotation tests. Further characterization work and flotation tests were rendered on samples from sampling location 6 (60°02'33.6"N 14°46'30.8"E). Previous work was done on samples from and near sampling location 1, which is southwest from location 6. Characterization methods performed on the material included elemental analysis through ICP-SFMS, X-ray diffraction measurements, and mineral liberation analysis as well as physical characterization through particle size distribution analysis and determination of specific gravity. Based on MLA, the material from the main samples showed good liberation by free surface which is important for flotation processes. Mineral association also showed low percentages between scheelite and other Ca-bearing minerals which is a main concern for scheelite flotation. Comparison of characterization work between the two sampling locations allows information on the repository at a larger scope. The common scheelite flotation collector sodium oleate, as well as novel formulations Atrac 2600 and Berol 8313 from Nouryon were tested in combination with the depressant sodium silicate. Based on mass recovery, grade and recovery, selectivity, required dosage, and the degree to which it is environmentally safe, Atrac 2600 at 400 g/t is deemed to produce the most positive results. Based on characterization of the material and flotation tests, an estimated 222,200 tons of -75 µm can go directly into the flotation circuit with an average grade of 0.2768% WO3 and 0.195% Cu. Approximately 15,000 tons at 0.50% WO3 and 14,000 tons at 0.224% Cu can be recovered at a single flotation. Rough mass balance of the process flowsheet indicates a Cu concentrate at 30% Cu will produce 880.50 tons, while a saleable scheelite concentrate at 65% WO3 will yield 672.16 tons from only the original -75 µm fraction of the material. Including the gravity separation tails intended to join the flotation circuit after grinding, an estimated 1,205.54 tons of scheelite at 65% WO3 and 1.860.20 tons of 30% Cu concentrate can be produced. Aside from this, the gravity separation circuit will still be able to yield 188,000 tons of 0.92% WO3 concentrate, which can be further studied if it can be beneficiated to a saleable product. Value estimation of the products for the recommended flowsheet indicate a total of US$ 17 million for the WO3 and Cu concentrates to be produced from the readily amenable -75 µm fraction to be treated directly by flotation. Inclusion of the gravity separation tails mass into the flotation feed yields a value estimated at US$32 million.
30

Report on Bellshazar [sic] mining property

Quinn, Matthew Vincent. January 1914 (has links) (PDF)
Thesis--University of Missouri, School of Mines and Metallurgy, 1914. / The entire thesis text is included in file. Typescript. Illustrated by author. Title from title screen of thesis/dissertation PDF file (viewed April 30, 2009)

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