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| 2. |
- Babanejad, Safoura, et al.
(författare)
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Mechanical Activation-Assisted Recovery of Valuable Metals from Black Mass in the Form of Fe/Cu Alloys
- 2023
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Ingår i: Journal of Sustainable Metallurgy. - : Springer. - 2199-3823 .- 2199-3831. ; 9:2, s. 522-536
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Tidskriftsartikel (refereegranskat)abstract
- Pyrometallurgy is a popular industrial method that is employed in the recovery of valuable elements from black mass (BM), which is produced by pretreatment of Li-ion batteries. This method struggles with some downsides, such as the incineration of graphite and high energy consumption. In this study, the goal is to utilize graphite in the BM to produce a master alloy in an attempt to decrease the energy input requirement. To achieve this, metal oxides (Fe2O3 and CuO) are added to the BM to produce an Fe/Cu-based alloy containing Co/Ni as alloying elements. Mechanical activation is also employed to decrease the energy requirement and to increase the amount of metal oxide that can be reduced by the graphite in the BM. The results revealed that it is possible to produce the aforementioned alloys, the efficiency of which can be improved by applying mechanical activation. After 1 h of milling, the required heat flow for producing Fe- and Cu-based alloys is lowered for ⁓10 and ⁓25 kWh, respectively. Plus, the direct CO2 emission decreases for 13-17% in the iron system and 43-46% in the copper system.
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| 3. |
- Haapakangas, Juho, et al.
(författare)
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Coke Reactivity in Simulated Blast Furnace Shaft Conditions
- 2016
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Ingår i: Metallurgical and materials transactions. B, process metallurgy and materials processing science. - : Springer Science and Business Media LLC. - 1073-5615 .- 1543-1916. ; 47:4, s. 2357-2370
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Tidskriftsartikel (refereegranskat)abstract
- Despite the fact that H2 and H2O are always present in the gas atmosphere of a blast furnace shaft, their role in the solution-loss reactions of coke has not been thoroughly examined. This study focuses on how H2 and H2O affect the reaction behavior and whether a strong correlation can be found between reactivity in the conditions of the CRI test (Coke Reactivity Index) and various simulated blast furnace shaft gas atmospheres. Partial replacement of CO/CO2 with H2/H2O was found to significantly increase the reactivity of all seven coke grades at 1373 K (1100 °C). H2 and H2O, however, did not have a significant effect on the threshold temperature of gasification. The reactivity increasing effect was found to be temperature dependent and clearly at its highest at 1373 K (1100 °C). Mathematical models were used to calculate activation energies for the gasification, which were notably lower for H2O gasification compared to CO2 indicating the higher reactivity of H2O. The reactivity results in gas atmospheres with CO2 as the sole gasifying component did not directly correlate with reactivity results in gases also including H2O, which suggests that the widely used CRI test is not entirely accurate for estimating coke reactivity in the blast furnace.
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| 4. |
- Heikkinen, Eetu-Pekka, et al.
(författare)
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A dialogue about teaching and learning metallurgy in Finland and Sweden
- 2019
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Ingår i: Pedaforum 5.–6.6. 2019 Helsinki. - : University of Helsinki. ; , s. 187-187
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Metallurgy is taught as a part of degree programmes of process and environmental engineering at the University of Oulu in Finland and at the Luleå University of Technology in Sweden. In both universities metallurgy education is organised by units very closely linked with metallurgical industry which is the most significant employer of the students graduating in metallurgy. The purpose of this presentation is to consider the state of pedagogy in the education of metallurgy in these two universities with a dialogue of teachers representing both universities. The aim is not only to find the similarities and differences, but also to find ways to improve teaching and learning based on the ideas raised in the dialogue. Key issues in the education of metallurgy, as in all engineering education, are the connections between theory and practice and how these connections are seen and adopted by students while their expertise in metallurgy develops. Our dialogue is based on how these connections are recognised and taken into account in teaching and learning of metallurgy as well as in the development of metallurgical expertise of both students and teachers. We will also discuss what kind of pedagogical solutions that can be used to support this development.
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| 5. |
- Lennartsson, Andreas
(författare)
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Development of a process model for a Peirce-Smith converter
- 2013
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Copper was one of the first metals ever extracted and used by mankind. It is used for its unique properties, like corrosion resistance, good workability, high thermal conductivity and attractive appearance. New mines are opened to maintain a supply of primary feedstock to copper smelters. These new deposits are in many instances found to have a more complex mineralogy with several minor elements. Besides treating primary material, copper smelters also show an increasing interest in treating secondary material, such as copper containing scrap from waste electric and electronic equipment, which also have a complex composition.Waste electric and electronic equipment are first disassembled and upgraded by mechanical processing, generating a product stream called e-scrap, that can be added directly to the smelting processes as cold material or melted in a separate furnace producing a metallic alloy (referred to as black copper) and a slag phase. The black copper can be refined in different ways, whereof one is by using it as a secondary feed material for input to Peirce-Smith converters. Consequently the load of minor elements to the converter can be expected to increase with an increased treatment of e-scrap.This increased complexity of the raw material can potentially lead to smelter plants having to deal with a feedstock containing several minor elements such as; antimony, bismuth, arsenic, gold, silver, etc. in levels that can influence the ability to, in a cost effective way, maintain the final grade of the copper cathode. Process simulations can be an important tool for understanding the impact of process parameters on the product quality and for the purpose of process optimisation. In the present work a dynamic, non-equilibrium model based on thermodynamics over the Peirce-Smith converter has been developed. The non-equilibrium conditions have been simulated by introducing individual but linked segments. The purpose of using segments was to consider different reaction zones which yield different conditions within the converter. The model was validated using plant data and showed good agreement for the major elements. The agreement between plant and calculated data for Pb, and Zn was not as good and more work is required regarding this aspect. The model was used to investigate the influence on the distribution of Bi and Sb during addition of black copper with or without slag. When black copper is added to a blow, the removal of Bi and Sb becomes lower compared to a blow without addition of black copper. Similar result is obtained during addition of black copper with slag. To maintain a total removal of Bi and Sb in similar levels as a blow without black copper, the black copper should be added as early as possible during the converting operation.
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