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- Bergamo, Pedro A. de S.
(författare)
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On the use of immersive technologies in the professional education of mineral processing
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- With the advance of technology, many educators started implementing immersive technologies like simulators and gamified learning applications to improve the trainings of process operators. However, it is noted that the minerals sector is significantly behind other industries, for instance, the chemical industry, especially when it comes to the evaluation of these types of trainings. Understanding how new technologies and concepts can improve the creation and evaluation of operator trainings, would perhaps create solutions for the lack of skilled operators in the mining sector, which is partly related to the challenge of evaluating time-dependent skills. In this scenario, this research aims to access the use of immersive technologies to increase the creation of operator talent in the minerals industry. In this context, an EU-funded network called “metalintelligence” exists. Its aim is to provide innovative research and equip a new generation of leaders in the minerals processing field providing lasting novel technological and training methods to build capacity in this growing area thus further establishing the EU’s leadership position in minerals processing. Hypothetically, the research in this field, backed by strong case studies, could provide valuable hints on how the trainings of operators could be made more efficient by using new technologies and concepts such as modelling and simulation and gamification. The study conducted within this thesis project can be divided into four parts, starting with a systematic review of how immersive technologies such as virtual reality (VR), educational games and simulation-based trainings have been used to teach different topics related to mining and mineral processing operations during the last 20 years. The current applications are mostly focused on hazard awareness and specific maneuvers of mining equipment, while only a few are related to the operation and management of the control rooms in mineral processing plants. During the review, it was noted that most papers found in the literature focus on the technical description of their solutions but fail to present an evaluation of the application by experts in the field. The review also found that further benefits can be achieved by employing tools like cloud solutions and gamification as these technologies can help with the collection of user data and improve the validation of technology-enhanced trainings. In the second part of this thesis, a case study is presented on how the current trainings of mineral process operators can benefit from immersive technologies. It involves the development and evaluation of a simulator-based training for froth flotation. The training was delivered to a group of operators at a greenfield process site and the analysis of the trainees’ evaluations were collected and discussed based on the first two levels of the Kirkpatrick evaluation model, a broadly used evaluation model. The reaction evaluation showed a strong satisfaction and a high learning perception from the trainees, while the learning evaluation, gathered with the help of the simulator, showed several weak spots in the training, especially when it came to teaching performance calculations. The disparity between the reaction and learning evaluations raises serious questions about evaluating trainings solely on the trainees’ feedback and goes against some principles of established evaluation methods such as Kirkpatrick’s. The third part of this study comprises the development of a training solution called “Minfloat”. It is an educational game developed in Unity3D focused on teaching the basic process behavior of froth flotation to operators and university students. It also describes the attempts to create a light-weight simulator core that could be run on a mobile device. After first testing a short-cut model, a model based on first principles was programmed and linked to the user interface. The game also includes an intelligent tutoring system (ITS) which presents concepts, examples, and questions pertinent to flotation performance calculations to the user. The principles of user experience (UX) design were used to produce assets (e.g., boxes, buttons, containers, and graphs) that could be re-used by other training developers, therefore promoting modularity, in a way that developers could use those to create their own educational games. The current game could be extended to basically every aspect of flotation, as also other mineral processes. In addition, the modules (such as assets, ITS, and graphs) could be re-used by other Unity3D developers to create trainings for topics in practically every process industry. The fourth and last part of the study involved the development of a questionnaire aiming to evaluate “Minfloat” in terms of overall quality, didactic efficacy, and inspiring character, besides having a better understanding of the target audience and outlook of the solution. To develop this questionnaire, the history of evaluation frameworks such as Kirkpatrick’s ‘Four levels’, Phillips’s ‘return on investment (ROI) based evaluation’ and Scriven’s ‘Goal-free evaluation’ are introduced to help clarifying the steps involved in assessing and evaluating a gamified educational solution like “Minfloat”.The questionnaire was applied to 25 experts in the minerals industry to access key aspects of the game-based training described earlier. From the results, three key lessons can be taken. The first is that users were, in general, satisfied with the game in terms of quality, efficacy and inspiring character. Second, users thought that the main target of the game should be university students, although novice industrial operators could also benefit from it. Third, the use of this short questionnaire, combined with the use of online forms, is a powerful tool for researchers who need a fast and efficient way to evaluate important aspects of a game and get feedback in written form.By analyzing the four parts of this research, some clear concluding benefits of the use of immersive technologies in operator training can be outlined. The first is that new engines such as Unity3D united with modelling and simulation, were proven to be powerful tools to create efficient, inspiring and non-expensive educational solutions for the process industry. Being a free software for personal or small companies, there is a big chance that, in the near future, engineering students will start using it to create their own educational trainings, and compete with larger companies which currently dominate that training market. Another contribution from this research is an evaluation form that provides training developers a way to get feedback for their application, improve their games or simulation-based trainings and produce more comprehensive articles about education in the minerals industry.The next step for this research would be to develop similar kinds of applications for other mineral beneficiation units and methods, such as comminution and hydrometallurgy. The game presented could even be expanded to teach the operation of an entire mineral processing plant. This way, university students and novice operators could learn and understand, in an inspiring way, important aspects of this type of operations, including material characterization, reagent usage, operational parameter setting, equipment design as well as financial and holistic operations of mineral processes. This development could revolutionize the teaching of mineral processes, the same way simulators leveled up the training of flight operators. However, this revolution will only occur if those immersive technologies are guided by the light of a proper and inexpensive evaluation, which will make sure that the technologies developed by academia are resonating in the same wavelength as the solutions of the industrial sector. Another aspect that immersive technologies could help with, is the declining rates of students entering university courses like mineral industry and geoscience. Digitalization solutions like the one described could help to inspire more students to choose a career in those fields, helping with the development of societies and their increasing needs for minerals.
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| 3. |
- Hruzova, Katerina
(författare)
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Potential of Organosolv Lignin Nanoparticles as a Sustainable Flotation Reagent : Towards a Low-Carbon Footprint Mining Industry
- 2024
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The green transition is driving a steep increase in the demand for minerals, which has put the focus on more responsible and sustainable mining practices as there is a growing pressure on mining operations to minimise their environmental footprint, mitigate risks in neighbouring communities, and decrease the consumption of natural resources. In 2022, mineral froth flotation was used to recover 18 million tonnes of copper from copper ore, accounting for 80% of total copper mine output. The mineral froth flotation process can be made more sustainable through the use of bio-based and biodegradable flotation reagents. Currently, xanthates are used as collectors for the recovery of copper-bearing sulfide minerals from sulfide ores. However, xanthates are fossil-based and pose significant risks, particularly to aquatic life and ecosystems. Additionally, a significant part of xanthates is currently obtained from production sites in Asia, which can lead to supply dependency and delays, as evident during the global pandemic.The aim of this thesis was to develop an efficient, sustainable, and environmentally friendly mineral froth flotation process based on total or partial replacement of xanthates with bio-based, biodegradable, and low-carbon footprint organosolv lignin particles (OLP). The lignin was obtained through organosolv fractionation of residual forest biomass, i.e. spruce and birch. The particles were produced via solvent exchange method from the homogenized lignin solution. As a result, 4 different particle types were produced: birch nanoparticles (BN), birch microparticles (BM), spruce nanoparticles (SN), and spruce microparticles (SM). At first, the characterization and surface chemistry study of the OLP was carried out to deepen the understanding of interaction mechanism between the OLP and mineral surfaces. The lignin was characterized by gel permeation chromatography and nuclear magnetic resonance for its molecular size and content of functional groups. While morphology, surface charge and stability in dispersion of the particles was determined using scanning electron microscopy, ζ-potential, and Turbiscan. All 4 particles were spherical with the diameter around 100 nm for nanoparticles and 1μm for microparticles. The ζ-potential measurement showed the surface variation caused by the difference in size and content of functional groups. Spruce particles, SN and SM, had higher negative charge due to higher content of carboxylic and total phenolic groups. Under alkali conditions, the ζ-potential below -20mV for all particles, with the lowest at −55.1 mV for SM. Finaly, the interaction of OLP with mineral surfaces was examined using quartz crystal microbalance. While the attachment of all OLP was very rigid for both, chalcopyrite and pyrite surfaces, the affinity for attachment was notably greater in the case of pyrite compared to chalcopyrite.The OLP was tested in proof-of-concept study on three different ore samples, and improvements in the flotation performance was observed, including better selectivity and increased recovery. The further evaluation of the OLP as flotation reagent was conducted with copper ore samples. The flotation trials were carried out with 600 g of ore sample in laboratory flotation cell. Starting with the dosage study, the results were confirmed in rougher-cleaner flotation tests. However, the OLP could not be used as a sole collector, it was shown that significant part of xanthate in the flotation mix could be replaced by OLP resulting in improved copper recovery and selectivity. Additionally, a synergy was observed when the OLP and xanthate mixture was used as combined reagents performed better than each of them separately at the same dosage. The copper recovery was increased from 82.2% to 88.7% in a semi-pilot rougher flotation when 50% of xanthate was replaced by OLP compared to the xanthate alone. Significant depression of iron recovery was observed when the OLP was utilized, even in absence of lime. Thus, the OLP reagents eliminated the need for lime, which is required on an industrial scale. Further positive effect of OLP application was indicated recovery of other valuable elements in the concentrates, such as cobalt and molybdenum, while there was no increase in penalty elements. The amount of OLP needed was up to 10 g/ton of ore, which is very small amount, and it is roughly 10 times less compared to any other modifier used in such a process. Therefore, this thesis demonstrates the potential of OLP as flotation reagent. If implemented, the proposed flotation system would lead to better resource efficiency and lower environmental impact.
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