Application Of Remelting Al-Mg-Cr Slag In Purging Plug Of Ladle

In recent years,due to the increasing demand for steel quality,the steelmaking technology and steelmaking process need to be improved.Refining technology is an important part of refining process,which can adjust the composition of molten steel and the temperature of molten steel,thereby improving the quality of steel and reducing the consumption of refractory materials.The Porous plug is the most critical functional element of the refining technology,and it plays a vital role in the reliability and completeness of the furnace refining.At present,due to the development of large-scale ladle,the melting temperature and melting time have been improved,the working environment of refractory in the use process is more and more harsh,.Therefore it is necessary to improve the service performance of porous brick to meet the requirements of contemporary steel making process and steel making technology.In this paper,the preparation of ladle brick is mainly made by remelting Al-Mg-Cr slag,tabular corundum,brown corundum,activited?-Al₂O₃ powder,fused magnesia,chromium oxide and calcium aluminate cement,the effect of the activited?-Al₂O₃ powder,pure calcium aluminate cement,SiO₂ powder,fused magnesia powder,micro chromium oxide,tabular corundum and brown corundum on the performance of Porous plug were studied,the microstructure of the samples are analyzed by scanning electron microscopy?SEM?,The results show that:?1?The addition amount of cement for the best experimental strength and high temperature performance of the sample is 4%.?2?The?-Al₂O₃ powder enhance the binding between the matrix and the aggregate.When the addition amount of?-Al₂O₃ powder is 13%,the samples are treated for 4h at 1550?,the CMOR and CCS are respectively 36 MPa and 96 MPa.?3?The addition of SiO₂ powder greatly improves the strength of the sample at room temperature after treating for 4h at 1550?.?4?The addition of the fused magnesia powder reacts with the reactive?-Al₂O₃in the matrix to form magnesia alumina spinel,which strengthens the binding degree between the matrix and reduces the apparent porosity.It can obtain the highest compressive strength and flexural strength,maximum bulk density,lowest apparent porosity and best slag resistance of the specimens after treating respectively at 1100?×4h and 1550×4h when the addition of fused magnesia is 5%.?5?Chromium oxide react with Al₂O₃ to forms a completely eutectic solid solution in the process of heating,which inhibits the corrosion of steel slag.?6?When considering the effect of different kinds of corundum,the best comprehensive performance of the samples with tabular corundum is the ratio of remelting Al Mg CR slag and tabular corundum is 1:1,and the best comprehensive performance of the samples with brown corundum is the ratio of remelting Al Mg CR slag and brown corundum is 1:0.