In the present study, the dissolution mechanism and rate of lime, limestone and dolomite in converter slag was studied. Lime dissolution in stagnant slag was studied first and dissolution of lime, limestone and dolomite under forced convection were carried out by new experimental setup. Dissolution of different CaO samples into stagnant converter slags was carried out in a closed tube furnace at 1873K. In the case of CaO-‘FeO’-SiO2 slag, the dissolution of CaO rod in the stagnant slag was retarded after the initial period (2 minutes). A dense layer of 2CaO∙SiO2 was found to be responsible for the total stop of the dissolution. It could be concluded that constant removal of the 2CaO∙SiO2 layer would be of essence to obtain high dissolution rate of lime. In this connection, it was found necessary to study the dissolution of lime in moving slag. In order to obtain reliable information of lime dissolution under forced convection, the commonly used rotating rod method was examined. Both CFD calculation and cold model experiments showed evidently that the mass transfer due to radial velocity introduced by forced convection was zero if the rod was centrally placed in a cylindrical container. A new experimental design was therefore developed. A cube was placed in the crucible and stirred by Mo rod along with slag. The whole system could be quenched in order to maintain the state of the system at high temperature. A linear relationship between normalized length and time was obtained for lime dissolution. Different lime samples showed big difference in dissolution rate. It was found that the main mechanism of CaO dissolution in slag was due to the removal of 2CaO∙SiO2 layer. Decomposition and dissolution of limestone and dolomite in slag at 1873 K were studied. The decomposition was carried out both in argon and in slag under argon atmosphere. The decomposition process was simulated using Comsol. The results showed evidently that the decomposition of limestone and dolomite was controlled mostly by heat transfer. It was also found that the decomposition of limestone product: CaO had very dense structure, no matter the sample was decomposed in slag or in argon. The slow decomposition and the dense CaO layer would greatly hinder the dissolution of lime in the slag. The present results clearly indicate that addition of limestone instead of lime would not be beneficial in converter process. Discontinuous 2CaO∙SiO2 layer along with MgO∙Fe2O3 particles was found on the surface of the dolomite sample. Some 2CaO∙SiO2 islands were found in the vicinity of the sample in the slag, which revealed therefore that the dissolution was dominated by the peeling-off of the layer of 2CaO∙SiO2-MgO∙Fe2O3 mixture. 2CaO∙SiO2, (Mg, Fe)Oss along with super cooled liquid phases were found inside dolomite sample close to the surface. 2CaO∙SiO2 phase was replaced gradually by 3CaO∙SiO2 towards the centre of the decomposed sample. / <p>QC 20120829</p>

Vanadin är en värdefull metall och kan lakas ur LD (Linz-Donawitz)-slagg med hjälp av vin. Ligander i vinet som lakar vanadin från LD-slagg studerades i denna rapport med mål att identifiera några av deras egenskaper såsom apparent molekylmassa och spektral information. Hyfenerad analys med hjälp av högupplösande vätskekromatografi-mikrovågsplasma med atomemissionspektrometer (HPLC-MP-AES) gjordes för att matcha vanadintoppen från vinet med ett apparent masspann från en gelfiltreringskolonn. Spektral analys visade att det fanns tre misstänkta vanadinligander i det analyserade vinet. Apparent molekylmassa hos liganderna var sannolikt inom spannet 24 Da – 570 Da. / Vanadium is a valuable metal and can be extracted from Linz-Donawitz (LD) converter slag using wine. Ligands in wine responsible for leaching vanadium from LD converter slag were studied in this report in an effort to identify some of their properties such as apparent molecular mass and spectral information. Hyphenated analysis using high performance liquid chromatography-microwave plasma atomic emission spectroscopy (HPLC-MP-AES) was performed to match a vanadium peak from the wine with an apparent mass span from a size exclusion chromatography (SEC) column. Spectral analysis of the vanadium peak revealed that there were three compounds suspected to be ligands to vanadium in the wine analyzed. Apparent molecular mass of the ligands wasfound to likely be between 24 Da - 570 Da.