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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.
111

Optimization of long-term quarry production planning to supply raw materials for cement plants

Vu, Dinh Trong 01 February 2022 (has links)
The success of a cement production project depends on the raw material supply. Longterm quarry production planning (LTQPP) is essential to maintain the supply to the cement plant. The quarry manager usually attempts to fulfil the complicated calculations, ensuring a consistent supply of raw materials to the cement plant while guaranteeing technical and operational parameters in mining. Modern quarry management relies on block models and mathematical algorithms integrated into the software to optimize the LTQPP. However, this method is potentially sensitive to geological uncertainty in resource estimation, resulting in the deviation of the supply production of raw materials. More importantly, quarry managers lack the means to deal with these requirements of LTQPP. This research develops a stochastic optimization framework based on the combination of geostatistical simulation, clustering, and optimization techniques to optimize the LTQPP. In this framework, geostatistical simulation techniques aim to model the quarry deposit while capturing the geological uncertainty in resource estimation. The clustering techniques are to aggregate blocks into selective mining cuts that reduce the optimization problem size and generate solutions in a practical timeframe. Optimization techniques were deployed to develop a new mathematical model to minimize the cost of producing the raw mix for the cement plant and mitigate the impact of geological uncertainty on the raw material supply. Matlab programming platform was chosen for implementing the clustering and optimization techniques and creating the software application. A case study of a limestone deposit in Southern Vietnam was carried out to verify the proposed framework and optimization models. Geostatistical simulation is applied to capture and transfer geological uncertainty into the optimization process. The optimization model size decreases significantly using the block clustering techniques and allowing generate solutions in a reasonable timeframe on ordinary computers. By considering mining and blending simultaneously, the optimization model minimizes the additive purchases to meet blending requirements and the amount of material sent to the waste dump. The experiments are also compared with the traditional optimization framework currently used for the deposit. The comparisons show a higher chance of ensuring a consistent supply of raw materials to the cement plant with a lower cost in the proposed framework. These results proved that the proposed framework provides a powerful tool for planners to optimize the LTQPP while securing the raw material supply in cement operations under geological uncertainty.:Title page _ i Declaration_ ii Acknowledgements _ i Publications during candidature_ii Abstract _iii Table of contents _v List of figures_viii List of tables _ xi List of abbreviations _xii Chapter 1 . Introduction _1 1.1 Background _1 1.2 Statement of the problem _2 1.3 Research aims and objectives_ 3 1.4 Scope of research _4 1.5 Research methodology _ 4 1.6 Significance of theresearch_5 1.7 Organization of thesis _6 Chapter 2 . Literature review _ 8 2.1 Introduction _ 8 2.2 Cement raw materials _8 2.3 Cement production process _ 8 2.3.1 Raw material recovery _9 2.3.2 Raw material processing_10 2.4 Impact of raw materials on the cement production process _12 2.5 Quarry planning and optimization _13 2.6 Long-term production planning (LTPP) problem _14 2.6.1 Deterministic approaches to solve the LTPP problem_15 2.6.2 Stochastic approaches for solving the LTPP problem_21 2.7 Conclusion_26 Chapter 3 . A stochastic optimization framework for LTQPP problem_28 3.1 Introduction_28 3.2 Deposit simulation_29 3.2.1 Simulating the rock type domains using SIS_30 3.2.2 Simulating the chemical grades within each domain conditionally to rock type domains, using SGS_30 3.3 Block clustering _31 3.4 The mathematical formulation for the LTQPP problem_32 3.4.1 Notation_34 3.4.2 Mathematical formulation_36 3.5 Numerical modelling_39 3.5.1 Clustering _39 3.5.2 SMIP formulation_41 3.6 Conclusion _47 Chapter 4 . Hierarchical simulation of cement raw material deposit_ 49 4.1 Introduction _49 4.2 Research area _ 50 4.2.1 General description_50 4.2.2. Data set_50 4.3. Application of hierarchical simulation _53 4.3.1 Rock-type simulation _ 53 4.3.2 Grade simulation _60 4.4. Discussion_73 4.5. Conclusion_76 Chapter 5 . Application of the stochastic optimization framework_77 5.1 Introduction_77 5.2 Implementation of KHRA _77 5.3 Implementation of the SMIP model _78 5.3.1 Sensitivity of the penalty cost _80 5.3.2 The effectiveness of the SMIP model _82 5.4 Risk mitigation _85 5.5 Conclusion _87 Chapter 6 . Conclusions and future works _ 89 6.1 Conclusions _89 6.2 Future works _91 References_ 93 Appendix I. Software Application _100 A.I.1 Introduction _100 A.I.2 Input preparation _101 A.I.2.1 Format of block model input _101 A.I.2.2 Import block model input _102 A.I.2.2 Cost assignment _104 A.I.2.3 Size reduction _ 107 A.I.3 Optimization _110 A.I.3.1 Destination _110 A.I.3.2 Production capacity _ 111 A.I.3.3 Additive purchase _ 111 A.I.3.4 Pit slopes _ 111 A.I.3.5 Optimization _ 112 A.I.4 Visualization of optimization results _112
112

Decision support system of coal mine planning using system dynamics model

Sontamino, Phongpat 11 March 2015 (has links) (PDF)
Coal is a fossil fuel mineral, which is presently a major source of electricity and energy to industries. From past to present, there are many coal reserves around the world and large scale coal mining operates in various areas such as the USA, Russia, China, Australia, India, and Germany, etc. Thailand’s coal resources can be found in many areas; there are lignite mining in the north of Thailand, the currently operational Mae Moh Lignite Mine, and also coal reserves in the south of Thailand, such as Krabi and Songkhla, where mines are not yet operating. The main consumption of coal is in electricity production, which increases annually. In 2019, the Thai Government and Electricity Generating Authority of Thailand (EGAT) plans to run a 800 MW coal power plant at Krabi, which may run on imported coal, despite there being reserves of lignite at Krabi; the use of domestic coal is a last option because of social and environmental concerns about the effects of coal mining. There is a modern trend in mining projects, the responsibility of mining should cover not only the mining activity, but the social and environmental protection and mine closure activities which follow. Thus, the costs and decisions taken on by the mining company are increasingly complicated. To reach a decision on investment in a mining project is not easy; it is a complex process in which all variables are connected. Particularly, the responsibility of coal mining companies to society and the environment is a new topic. Thus, a tool to help to recognize and generate information for decision making is in demand and very important. In this thesis, the system dynamics model of coal mine planning is made by using Vensim Software and specifically designed to encompass many variables during the period of mining activity until the mine closure period. The decisions use economic criteria such as Net Present Value (NPV), Net Cash Flow (NCF), Payback Period (PP), and Internal Rate of Return (IRR), etc. Consequently, the development of the decision support system of coal mine planning as a tool is proposed. The model structure covers the coal mining area from mine reserves to mine closure. It is a fast and flexible tool to perform sensitivity analysis, and to determine an optimum solution. The model results are clear and easily understandable on whether to accept or reject the coal mine project, which helps coal mining companies make the right decisions on their policies, economics, and the planning of new coal mining projects. Furthermore, the model is used to analyse the case study of the Krabi coal-fired power plant in Thailand, which may possibly use the domestic lignite at Krabi. The scenario simulations clearly show some potential for the use of the domestic lignite. However, the detailed analysis of the Krabi Lignite Mine Project case shows the high possible risks of this project, and that this project is currently not feasible. Thus, the model helps to understand and confirm that the use of domestic lignite in Krabi for the Krabi Coal Power Plant Project is not suitable at this time. Therefore, the best choice is imported coal from other countries for supporting the Krabi Coal Power Plant Project. Finally, this tool successfully is a portable application software, which does not need to be installed on a computer, but can run directly in a folder of the existing application. Furthermore, it supports all versions of Windows OS.
113

Decision support system of coal mine planning using system dynamics model

Sontamino, Phongpat 05 December 2014 (has links)
Coal is a fossil fuel mineral, which is presently a major source of electricity and energy to industries. From past to present, there are many coal reserves around the world and large scale coal mining operates in various areas such as the USA, Russia, China, Australia, India, and Germany, etc. Thailand’s coal resources can be found in many areas; there are lignite mining in the north of Thailand, the currently operational Mae Moh Lignite Mine, and also coal reserves in the south of Thailand, such as Krabi and Songkhla, where mines are not yet operating. The main consumption of coal is in electricity production, which increases annually. In 2019, the Thai Government and Electricity Generating Authority of Thailand (EGAT) plans to run a 800 MW coal power plant at Krabi, which may run on imported coal, despite there being reserves of lignite at Krabi; the use of domestic coal is a last option because of social and environmental concerns about the effects of coal mining. There is a modern trend in mining projects, the responsibility of mining should cover not only the mining activity, but the social and environmental protection and mine closure activities which follow. Thus, the costs and decisions taken on by the mining company are increasingly complicated. To reach a decision on investment in a mining project is not easy; it is a complex process in which all variables are connected. Particularly, the responsibility of coal mining companies to society and the environment is a new topic. Thus, a tool to help to recognize and generate information for decision making is in demand and very important. In this thesis, the system dynamics model of coal mine planning is made by using Vensim Software and specifically designed to encompass many variables during the period of mining activity until the mine closure period. The decisions use economic criteria such as Net Present Value (NPV), Net Cash Flow (NCF), Payback Period (PP), and Internal Rate of Return (IRR), etc. Consequently, the development of the decision support system of coal mine planning as a tool is proposed. The model structure covers the coal mining area from mine reserves to mine closure. It is a fast and flexible tool to perform sensitivity analysis, and to determine an optimum solution. The model results are clear and easily understandable on whether to accept or reject the coal mine project, which helps coal mining companies make the right decisions on their policies, economics, and the planning of new coal mining projects. Furthermore, the model is used to analyse the case study of the Krabi coal-fired power plant in Thailand, which may possibly use the domestic lignite at Krabi. The scenario simulations clearly show some potential for the use of the domestic lignite. However, the detailed analysis of the Krabi Lignite Mine Project case shows the high possible risks of this project, and that this project is currently not feasible. Thus, the model helps to understand and confirm that the use of domestic lignite in Krabi for the Krabi Coal Power Plant Project is not suitable at this time. Therefore, the best choice is imported coal from other countries for supporting the Krabi Coal Power Plant Project. Finally, this tool successfully is a portable application software, which does not need to be installed on a computer, but can run directly in a folder of the existing application. Furthermore, it supports all versions of Windows OS.
114

Übertragung von Prinzipien der Ameisenkolonieoptimierung auf eine sich selbst organisierende Produktion

Bielefeld, Malte 12 July 2019 (has links)
Die Bachelorarbeit behandelt die Themen der Selbstorganisation in Produktionssystemen im Kontext von Industrie 4.0. Dabei wird gezeigt, wie man mithilfe von einer Ameisenkolonieoptimierung die Reihenfolgeplanung organisieren kann.:Abbildungsverzeichnis Tabellenverzeichnis Formelverzeichnis 1. Einleitung 1.1. Motivation 1.2. Ziele 1.3. Vorgehensweise 2. Sich selbst organisierende Produktionen 2.1. Begriffserklärung 2.2. Stand der Technik 2.3. Reihenfolgeplanung als ein Problem der Selbstorganisation 2.3.1. Begriffserklärung 2.3.2. Stand der Technik 2.3.3. Umsetzung in einer Selbstorganisation 3. Ameisenkolonieoptimierung 3.1. Begriffserklärung 3.2. Allgemeine Umsetzung 3.3. Konkrete Umsetzungen 3.4. Vor- und Nachteile 3.5. Anwendungsbeispiele 4. Entwicklung einer Ameisenkolonieoptimierung für ein sich selbst organisierendes Produktionssystem 4.1. Analyse des gegebenen sich selbst organisierenden Produktionssystems 4.1.1. Grobanalyse des Systems 4.1.2. Feinanalyse der bisherigen Reihenfolgeplanung 4.2. Entwurf der Reihenfolgeplanung durch Prinzipien der Ameisenkolonieoptimierung 4.3. Implementierung der Prinzipien der Ameisenkolonieoptimierung 5. Empirische Untersuchung der implementierten Ameisenkolonieoptimierung 5.1. Beschreibung der gegebenen Produktionsdaten 5.2. Szenarienuntersuchung zur Funktionsfähigkeit 5.2.1. Schichtwechselszenario 5.2.2. Abnutzungs- und Wartungsszenario 5.2.3. Vergleichsszenario 5.3. Untersuchung hinsichtlich der Laufzeit und des Speicherbedarfs 5.3.1. Laufzeit 5.3.2. Speicherbedarf 6. Zusammenfassung und Ausblick 6.1. Zusammenfassung 6.2. Ausblick Quellenverzeichnis / The bachelor thesis is about self organization in production systems in the context of Industry 4.0. Its about ant colony optimization for scheduling in the production planning.:Abbildungsverzeichnis Tabellenverzeichnis Formelverzeichnis 1. Einleitung 1.1. Motivation 1.2. Ziele 1.3. Vorgehensweise 2. Sich selbst organisierende Produktionen 2.1. Begriffserklärung 2.2. Stand der Technik 2.3. Reihenfolgeplanung als ein Problem der Selbstorganisation 2.3.1. Begriffserklärung 2.3.2. Stand der Technik 2.3.3. Umsetzung in einer Selbstorganisation 3. Ameisenkolonieoptimierung 3.1. Begriffserklärung 3.2. Allgemeine Umsetzung 3.3. Konkrete Umsetzungen 3.4. Vor- und Nachteile 3.5. Anwendungsbeispiele 4. Entwicklung einer Ameisenkolonieoptimierung für ein sich selbst organisierendes Produktionssystem 4.1. Analyse des gegebenen sich selbst organisierenden Produktionssystems 4.1.1. Grobanalyse des Systems 4.1.2. Feinanalyse der bisherigen Reihenfolgeplanung 4.2. Entwurf der Reihenfolgeplanung durch Prinzipien der Ameisenkolonieoptimierung 4.3. Implementierung der Prinzipien der Ameisenkolonieoptimierung 5. Empirische Untersuchung der implementierten Ameisenkolonieoptimierung 5.1. Beschreibung der gegebenen Produktionsdaten 5.2. Szenarienuntersuchung zur Funktionsfähigkeit 5.2.1. Schichtwechselszenario 5.2.2. Abnutzungs- und Wartungsszenario 5.2.3. Vergleichsszenario 5.3. Untersuchung hinsichtlich der Laufzeit und des Speicherbedarfs 5.3.1. Laufzeit 5.3.2. Speicherbedarf 6. Zusammenfassung und Ausblick 6.1. Zusammenfassung 6.2. Ausblick Quellenverzeichnis

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