Developing practices for protective sand in slag pots
Pisilä, Eeva-Liisa (2017)
Pisilä, Eeva-Liisa
Oulun ammattikorkeakoulu
2017
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Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:amk-2017100415702
https://urn.fi/URN:NBN:fi:amk-2017100415702
Tiivistelmä
This thesis was commissioned by SSAB Merox. The object of the thesis was to study and develop the practices related to protecting the slag pots with the protective sand in the Raahe steel plant. The desulphurisation slag and ladle slag pots are cooled off for couple of days and the LD slag pots are emptied right away when produced. The purpose of the thesis was to do a literature study about the usage of the protective sand globally. Additionally a testing period was to be carried out with the possible new materials found from the literature and with the materials that have already been in use at Raahe steel plant, the natural sand and the LD slag.
The literature study was done by searching information from internet databases and books found in the library of the Raahe steel plant. The protective sand was not mentioned in the literature found in the study. There were no internal reports about the subject. The information of the usage in the other steel plants of the SSAB was gathered by interviews. Since new materials were not found, the natural sand and the LD slag were decided to be tested with different amounts. The follow-up of the tests was conducted by gathering the data about how well the pots emptied, observing the emptying of the pots and interviewing the slag pot carrier truck drivers.
As the result of the tests it was noticed that the desulphurisation slag and ladle slag pots emptied well with both materials and even with smaller amounts. The amount of the protective sand in these pots could be reduced to at least 400 kg. The LD slag pots instead had problems even with larger amounts of the protective sand. Because of the impreciseness of the test results it is hard to determine which material was the absolute best. The amount of the protective sand in LD slag pots might need to be increased. The functionality of the sanding station in which the slag pots are fed with the protective sand should be reviewed and the feeding of the sand should be developed.
The literature study was done by searching information from internet databases and books found in the library of the Raahe steel plant. The protective sand was not mentioned in the literature found in the study. There were no internal reports about the subject. The information of the usage in the other steel plants of the SSAB was gathered by interviews. Since new materials were not found, the natural sand and the LD slag were decided to be tested with different amounts. The follow-up of the tests was conducted by gathering the data about how well the pots emptied, observing the emptying of the pots and interviewing the slag pot carrier truck drivers.
As the result of the tests it was noticed that the desulphurisation slag and ladle slag pots emptied well with both materials and even with smaller amounts. The amount of the protective sand in these pots could be reduced to at least 400 kg. The LD slag pots instead had problems even with larger amounts of the protective sand. Because of the impreciseness of the test results it is hard to determine which material was the absolute best. The amount of the protective sand in LD slag pots might need to be increased. The functionality of the sanding station in which the slag pots are fed with the protective sand should be reviewed and the feeding of the sand should be developed.