| 1. |
- Andersson, Anton, et al.
(författare)
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A holistic and experimentally-based view on recycling of off-gas dust within the integrated steel plant
- 2018
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Ingår i: Metals. - Basel : MDPI AG. - 2075-4701. ; 8:10
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Tidskriftsartikel (refereegranskat)abstract
- Ore-based ironmaking generates a variety of residues, including slags and fines such as dust and sludges. Recycling of these residues within the integrated steel plant or in other applications is essential from a raw-material efficiency perspective. The main recycling route of off-gas dust is to the blast furnace (BF) via sinter, cold-bonded briquettes and tuyere injection. However, solely relying on the BF for recycling implicates that certain residues cannot be recycled in order to avoid build-up of unwanted elements, such as zinc. By introducing a holistic view on recycling where recycling via other process routes, such as the desulfurization (deS) station and the basic oxygen furnace (BOF), landfilling can be avoided. In the present study, process integration analyses were utilized to determine the most efficient recycling routes for off-gas dust that are currently not recycled within the integrated steel plants of Sweden. The feasibility of recycling was studied in experiments conducted in laboratory, pilot, and full-scale trials in the BF, deS station, and BOF. The process integration analyses suggested that recycling to the BF should be maximized before considering the deS station and BOF. The experiments indicated that the amount of residue that are not recycled could be minimized.
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| 2. |
- Andersson, Anton, et al.
(författare)
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Recycling of Blast Furnace Sludge to the Blast Furnace via Cold-Bonded Briquettes: Evaluation of Feasibility and Influence on Operation
- 2019
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Ingår i: ISIJ International. - : Iron and Steel Institute of Japan. - 0915-1559 .- 1347-5460. ; 59:10, s. 1786-1795
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Tidskriftsartikel (refereegranskat)abstract
- Ore-based steelmaking generates various residues including dusts, sludges, scales and slags. Recycling of these residues within the process or via other applications is essential for sustainable production of steel. In blast furnace (BF) ironmaking, the gas-cleaning equipment generally recovers the particles in the off-gas as dust and sludge. Traditionally, the dry dust is recycled via the sinter or, in the case of pellet-based BF operation, via cold-bonded briquettes and injection. As the BF sludge mainly consists of iron and carbon, this residue is of interest to recycle together with the BF dust. However, depending on how the BF is operated, these two residues are more or less the major outlet of zinc from the furnace. Thus, to limit the recycled load of zinc, both materials cannot be recycled without dezincing the sludge prior to recycling. Dezincing and recycling of the low-zinc fraction of BF sludge via sinter have been reported whereas recycling via cold-bonded briquettes has not been performed. In the present study, cold-bonded briquettes containing the low-zinc fraction of dezinced BF sludge were charged as basket samples to the LKAB Experimental Blast Furnace (EBF). The excavated basket samples from the quenched EBF suggested that additions of up to 20 wt.% of upgraded BF sludge was feasible in terms of reducibility and strength. Based on these results, BF sludge were added to cold-bonded briquettes and charged in industrial-scale trials. The trials indicated that the annual generation of BF sludge, after dezincing, could be recycled to the BF.
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| 3. |
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| 4. |
- Andersson, Anton, et al.
(författare)
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Upgrading of Blast Furnace Sludge and Recycling of the Low-Zinc Fraction via Cold-bonded Briquettes
- 2019
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Ingår i: Journal of Sustainable Metallurgy. - : Springer. - 2199-3823 .- 2199-3831. ; :3, s. 350-361
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Tidskriftsartikel (refereegranskat)abstract
- Depending on the operation of the blast furnace (BF), the main outlet of zinc from the furnace is more or less via the BF dust and sludge. As the dust is recycled to the BF, the sludge has to be de-zinced prior to recycling to prevent the accumulation of zinc in the BF. De-zincing and recycling of the low-zinc fraction via sinter have been reported. However, no research con-cerning recycling of upgraded BF sludge via cold-bonded briquettes has been performed. In the present study, a fine-grained BF sludge with low zinc content, generated by a BF operating on a ferrous burden of 100% pellets, was upgraded using the tornado process. The process simultaneously dried and separated the BF sludge into a high-zinc and a low-zinc fraction. The feasibility of recycling the low-zinc fraction to the BF using cold-bonded briquettes was studied on a laboratory-scale BF shaft simulator. On comparison with a reference briquette, the experiments indicated that 10 wt% of the upgraded BF sludge can be added to the briquette without negatively affecting the reducibility. Higher additions were found to render the briquette less reduced compared to the reference under test conditions corresponding to the central part of the BF. The strength of the briquettes was not compromised with the addition of the upgraded BF sludge, and a decision to study the briquettes in the LKAB experimental blast furnace was made in order to evaluate the behavior under actual BF conditions.
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| 5. |
- Brown, Amanda, et al.
(författare)
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Bidirectional cross-linguistic influence in event conceptualization? Expressions of Path among Japanese learners of English
- 2011
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Ingår i: Bilingualism: Language and Cognition. - 1366-7289. ; 14:1, s. 79-94
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Tidskriftsartikel (refereegranskat)abstract
- Typological differences in expressions of motion are argued to have consequences for event conceptualization. In SLA, studies generally find transfer of L1 expressions and accompanying event construals, suggesting resistance to the restructuring of event conceptualization. The current study tackles such restructuring in SLA within the context of bidirectional cross-linguistic influence, focusing on expressions of Path in English and Japanese. We probe the effects of lexicalization patterns on event construal by focusing on different Path components: Source, Via and Goal. Crucially, we compare the same speakers performing both in the L1 and L2 to ascertain whether the languages influence each other. We argue for the potential for restructuring, even at modest levels of L2 proficiency, by showing that not only do L1 patterns shape construal in the L2, but that L2 patterns may subtly and simultaneously broaden construal in the L1 within an individual learner.
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| 6. |
- Brown, Amanda, et al.
(författare)
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Changes in encoding of path of motion after acquisition of a second language
- 2010
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Ingår i: Cognitive Linguistics. - 1613-3641. ; 21:2, s. 263-286
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Tidskriftsartikel (refereegranskat)abstract
- Languages vary typologically in their lexicalization of Path of motion (Talmy 1991). Furthermore, lexicalization patterns are argued to affect syntactic packaging at the level of the clause (e.g. Slobin 1996b) and tend to transfer from a first (L1) to a second language (L2) in second language acquisition (e.g. Cadierno 2004). From this crosslinguistic and developmental evidence, typological preferences for Path expression appear highly robust features of a first language. The current study examines the extent to which preferences for Path encoding really are as enduring as they seem by investigating (1) whether Japanese follows patterns identified for other verb-framed languages like Spanish, and (2) whether patterns established in one’s first language can change after acquisition of a second language. L1 performance of native speakers of Japanese with intermediate-level knowledge of English was compared to that of monolingual speakers of Japanese and English. Results showed that monolingual Japanese speakers followed basic lexicalization patterns typical of other verb-framed languages, but with different realizations of Path packaging within the clause. Moreover, non-monolingual Japanese speakers displayed both English- and Japanese-like patterns for lexicalization with significantly more Path information per clause than either group of monolinguals. Implications for typology and second language acquisition are discussed.
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| 7. |
- Brown, Amanda, et al.
(författare)
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L1-L2 convergence in clausal packaging in Japanese and English
- 2013
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Ingår i: Bilingualism: Language and Cognition. - 1366-7289. ; 16:3, s. 477-494
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Tidskriftsartikel (refereegranskat)abstract
- This study investigates L1-L2 convergence among bilinguals at an intermediate (CEFR-B2) level of L2 proficiency, focusing on the clausal packaging of Manner and Path of motion. Previous research has shown that Japanese speakers use multi-clause and English speakers single-clause constructions (Allen et al., 2003; Kita & Özyürek, 2003). We compared descriptions of motion from monolingual English and Japanese speakers to L1 and L2 descriptions from Japanese speakers of English as a second (ESL) and foreign (EFL) language. Contrary to previous research, results showed no significant difference between the monolinguals, who predominately used single-clause constructions packaging Manner and Path. However, bilinguals used significantly more multi-clause constructions in both their L1 and L2, with no effects of residence in the L2 community. Following Pavlenko (2011a), findings are interpreted as evidence for L1-L2 convergence. We discuss potential bidirectional cross-linguistic influences underpinning the L1-L2 convergence and implications for the restructuring of bilingual grammars.
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| 8. |
- Brown, Amanda, et al.
(författare)
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Multicompetence and native speaker variation in clausal packaging in Japanese
- 2012
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Ingår i: Second Language Research. - : SAGE Publications. - 0267-6583 .- 1477-0326. ; 28:4, s. 415-442
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Tidskriftsartikel (refereegranskat)abstract
- Native speakers show systematic variation in a range of linguistic domains as a function of a variety of sociolinguistic variables. This article addresses native language variation in the context of multicompetence, i.e. knowledge of two languages in one mind (Cook, 1991). Descriptions of motion were elicited from functionally monolingual and non-monolingual speakers of Japanese, with analyses focusing on clausal packaging of Manner and Path. Results revealed that (1) acquisition of a second language (L2) appears to affect how speakers distribute information about motion in and across clauses in their first language (L1); (2) these effects can be seen with rather less knowledge of a second language than the advanced bilingual proficiency level typically studied; and (3) there appears to be little effect of L2 immersion in this domain since Japanese users of English as a second language (ESL) did not differ from Japanese users of English as a foreign language (EFL). We discuss the findings with respect to characterizations of emerging multicompetent grammars, and to implications for the construct of ‘the native speaker’, for language pedagogy and language assessment.
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| 9. |
- Gullberg, Amanda, et al.
(författare)
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ALKALI IN THE BLAST FURNACE – INFLUENCE OF MODIFIED ASH COMPOSITION IN COKE AND CHARGING PRACTICE
- 2018
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The presence of alkalis (Na, K) in the blast furnace process (BF) is known to have negative influences on the process due to the catalytic effect on coke gasification, destruction of carbon structure by intercalation of alkali, scaffold formation and refractory attack. The nature of alkali compounds combined with the character of the process causes alkalis to recirculate and accumulate in the BF. Within this study, the distribution of alkali at different depths in the shaft for different charging practices has been studied by examination of excavated coke samples from LKAB’s Experimental Blast Furnace. A possible way of controlling the alkali load in blast furnace has been investigated by studying coke with modified ash composition for binding alkali in stable phases that can be drained out from BF with the slag.
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| 10. |
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