Up-Concentration of Chromium in Stainless Steel Slag and Ferrochromium Slags by Magnetic and Gravity Separation
Slags coming from stainless steel (SS) and ferrochromium (FeCr) production generally contain between 1 and 10% Cr, mostly present in entrapped metallic particles (Fe–Cr alloys) and in spinel structures. To recover Cr from these slags, magnetic and gravity separation techniques were tested for up-con...
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| Format: | Article |
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MDPI AG
2020-10-01
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| Series: | Minerals |
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| Online Access: | https://www.mdpi.com/2075-163X/10/10/906 |
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| author | Frantisek Kukurugya Peter Nielsen Liesbeth Horckmans |
| author_facet | Frantisek Kukurugya Peter Nielsen Liesbeth Horckmans |
| author_sort | Frantisek Kukurugya |
| collection | DOAJ |
| description | Slags coming from stainless steel (SS) and ferrochromium (FeCr) production generally contain between 1 and 10% Cr, mostly present in entrapped metallic particles (Fe–Cr alloys) and in spinel structures. To recover Cr from these slags, magnetic and gravity separation techniques were tested for up-concentrating Cr in a fraction for further processing. In case of SS slag and low carbon (LC) FeCr slag a wet high intensity magnetic separation can up-concentrate Cr in the SS slag (fraction <150 µm) from 2.3 wt.% to almost 9 wt.% with a yield of 7 wt.%, and in the LC FeCr slag from 3.1 wt.% to 11 wt.% with a yield of 3 wt.%. Different behavior of Cr-containing spinel’s in the two slag types observed during magnetic separation can be explained by the presence or absence of Fe in the lattice of the Cr-containing spinel’s, which affects their magnetic susceptibility. The Cr content of the concentrates is low compared to chromium ores, indicating that additional processing steps are necessary for a recovery process. In the case of high carbon (HC) FeCr slag, a Cr up-concentration by a factor of more than three (from 9 wt.% to 28 wt.%) can be achieved on the as received slag, after a single dry low intensity magnetic separation step, due to the well-liberated Cr-rich compounds present in this slag. After gravity separation of the HC FeCr slag, a fraction with a Cr content close to high grade Cr ores (≥50% Cr<sub>2</sub>O<sub>3</sub>) can be obtained. This fraction represents 12 wt.% of the HC FeCr slag, and can probably be used directly in traditional smelting processes. |
| first_indexed | 2024-03-10T15:41:44Z |
| format | Article |
| id | doaj.art-b9c8789fb085476a91caa4a21cc1d141 |
| institution | Directory Open Access Journal |
| issn | 2075-163X |
| language | English |
| last_indexed | 2024-03-10T15:41:44Z |
| publishDate | 2020-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Minerals |
| spelling | doaj.art-b9c8789fb085476a91caa4a21cc1d1412023-11-20T16:47:24ZengMDPI AGMinerals2075-163X2020-10-01101090610.3390/min10100906Up-Concentration of Chromium in Stainless Steel Slag and Ferrochromium Slags by Magnetic and Gravity SeparationFrantisek Kukurugya0Peter Nielsen1Liesbeth Horckmans2Vlaamse Instelling Voor Technologisch Onderzoek (VITO), 2400 Mol, BelgiumVlaamse Instelling Voor Technologisch Onderzoek (VITO), 2400 Mol, BelgiumVlaamse Instelling Voor Technologisch Onderzoek (VITO), 2400 Mol, BelgiumSlags coming from stainless steel (SS) and ferrochromium (FeCr) production generally contain between 1 and 10% Cr, mostly present in entrapped metallic particles (Fe–Cr alloys) and in spinel structures. To recover Cr from these slags, magnetic and gravity separation techniques were tested for up-concentrating Cr in a fraction for further processing. In case of SS slag and low carbon (LC) FeCr slag a wet high intensity magnetic separation can up-concentrate Cr in the SS slag (fraction <150 µm) from 2.3 wt.% to almost 9 wt.% with a yield of 7 wt.%, and in the LC FeCr slag from 3.1 wt.% to 11 wt.% with a yield of 3 wt.%. Different behavior of Cr-containing spinel’s in the two slag types observed during magnetic separation can be explained by the presence or absence of Fe in the lattice of the Cr-containing spinel’s, which affects their magnetic susceptibility. The Cr content of the concentrates is low compared to chromium ores, indicating that additional processing steps are necessary for a recovery process. In the case of high carbon (HC) FeCr slag, a Cr up-concentration by a factor of more than three (from 9 wt.% to 28 wt.%) can be achieved on the as received slag, after a single dry low intensity magnetic separation step, due to the well-liberated Cr-rich compounds present in this slag. After gravity separation of the HC FeCr slag, a fraction with a Cr content close to high grade Cr ores (≥50% Cr<sub>2</sub>O<sub>3</sub>) can be obtained. This fraction represents 12 wt.% of the HC FeCr slag, and can probably be used directly in traditional smelting processes.https://www.mdpi.com/2075-163X/10/10/906stainless steel slagferrochromium slagmagnetic separationgravity separation |
| spellingShingle | Frantisek Kukurugya Peter Nielsen Liesbeth Horckmans Up-Concentration of Chromium in Stainless Steel Slag and Ferrochromium Slags by Magnetic and Gravity Separation Minerals stainless steel slag ferrochromium slag magnetic separation gravity separation |
| title | Up-Concentration of Chromium in Stainless Steel Slag and Ferrochromium Slags by Magnetic and Gravity Separation |
| title_full | Up-Concentration of Chromium in Stainless Steel Slag and Ferrochromium Slags by Magnetic and Gravity Separation |
| title_fullStr | Up-Concentration of Chromium in Stainless Steel Slag and Ferrochromium Slags by Magnetic and Gravity Separation |
| title_full_unstemmed | Up-Concentration of Chromium in Stainless Steel Slag and Ferrochromium Slags by Magnetic and Gravity Separation |
| title_short | Up-Concentration of Chromium in Stainless Steel Slag and Ferrochromium Slags by Magnetic and Gravity Separation |
| title_sort | up concentration of chromium in stainless steel slag and ferrochromium slags by magnetic and gravity separation |
| topic | stainless steel slag ferrochromium slag magnetic separation gravity separation |
| url | https://www.mdpi.com/2075-163X/10/10/906 |
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