الفهرس | Only 14 pages are availabe for public view |
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. |