Melting Slag Characteristic Of Titanium-bearing Blast Furnace Slag And Its Application Research

This thesis focused on the efficient utilization of the titanium-bearing blast furnace slag and to alleviate the serious problem of slag adhesion on ramming refractory in Panzhihua Iron and Steel Company. First of all, the melting characteristics of titanium-bearing blast furnace slag before and after the carbonitridation process were studied. In the same time, the influence of Ti(C,N), clay, bauxite, corundum and boron compounds on the melting characteristics of titanium-bearing blast furnace slag were also studied. To further illustrate the specific feature of titanium-bearing blast furnace slag, blast furnace mud gun , through castable and the ramming refractory corroded by the ordinary blast furnace slag and the titanium-bearing slag in Panzhihua Iron and Steel Company were investigated. Finally, general physical properties, oxidation and slag erosion resistance of ramming refractory were studied. The comparison ramming refractories with the ordinary blast furnace slag and boron-containing additives were performed, when the titanium-bearing blast furnace slag before and after the carbonitridation process were directly introduced into the ramming refractory. The main conclusions are listed as follows:Firstly, the melting temperature of the titanium-bearing slag under the carbonitridation process gradually increased with the carbon ratio and carbonitridation temperature, especially for the flowing point. These different types of refractories including clay, bauxite and corundum can increase the melting temperature of the titanium-bearing slag respectively. With the increase of each raw material, the melting temperature rised continuously, that is to say, with the increase of Al2O3, and the decrease of SiO2 and other impurities, the melting temperature of the titanium-bearing slag increased. When the addition of Ti (C, N) is more than 6%, it can improve the melting temperature of the titanium-bearing slag. Boron anhydride and boron-containing additive could reduce the melting temperature of the titanium-bearing slag significantly, and however, it occurred abnormally when the content of boron compounds are in the range of 0.5% to 1%. The ordinary blast furnace slag has the same melting characteristic as the titanium-bearing slag when refractory raw materials were added in ramming refractories.Secondly, the titanium-bearing slag has no obvious erosion and infiltration on the blast furnace mud gun, through castable and ramming refractory of Al2O3-SiC-C. But the ordinary blast furnace slag can react easily with refractories to generate low-melting liquid phase, and lead to the erosion damage. When the boron-containing additive is more than 0.5%, it can decrease the slag corrosion.Thirdly, when SiC of ramming refractory was replaced by part or all of titanium-bearing blast furnace slag before and after the carbonitridation process, it can improve the oxidation resistance of ramming refractories significantly, but give no affection to the slag resistance. It can be deduced that the problem of slag adhesion on ramming refractories can be solved on the basis of improving other general physical properties.