الفهرس 
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Abstract
Optimizing EAF slag chemistry to obtain suitable foaming
characteristics is mandatory for steelmakers to keep running with an
adequate operational cost. Therefore, this work deals with the effect of slag
magnesia content on slag foaming and refractory consumption.
A study was done to investigate the severe effect of using 100% DRI
charge on refractory consumption. Experimental tests (XRF and EDAX)
were used to investigate the chemical composition and microstructure for
magnesia carbon refractory and the slag. Cup test was used for relating the
refractory wear along with the slag composition and for determination of
the optimum MgO weight percent in slag. An on-line study at Suez Steel
Company (SSC) shows the relation between MgO fluxing content in feed
charge and the refractory consumption, in terms of (mm/heat) and lost MgO
weight taken from refractory to the output slag in tons.
Experimental tests show that loss of carbon of the matrix as a result of
slag attack, while cup test shows that the optimum MgO weight percent in
slag is around 12%. As this work aims to improve refractory consumptions
in SSC-EAF using a higher MgO content material, the saturation percent for
MgO in slag was calculated based on solubility diagram and cup test results.
A modification done for the fluxing additions to achieve the requirements of
MgO and CaO weight percent in slag, aiming to decrease the compositional
difference between refractory and slag that derives refractory attack.
Saturating slag with MgO was done by replacing the old fluxing practice
(50 kg of dololime /TMS) by the new fluxing practice (25 kg of dololime/TMS in addition to 50 kg of burnt dolomite /TMS). The effect of
flux modification on refractory consumption was compared in both cases.
Refractory wear rate has diminished from 0.658 to 0.432 mm per heat
resul ng in cost saving by 5.61 USD/TMS.