Study On The Damage Process And Its Influencing Factors Of The Refractory Material Of The Refining Ladle Slag Line By Rotary Impregnation

In the process of iron and steel production,MgO-C brick used at refining ladle slag line has a serious damage,so it has a short using cycle.To prolong the service life of MgO-C brick,reduce the production cost and ensure the safe operation of the ladle,studying the damage process of refractory used in slag line and the damage factors is particularly important.In this paper,MgO-C brick(carbon content of 17wt%)was used as the research object and tested its physical and chemical indexes.The slag corrosion resistance of magnesia-carbon brick samples at different temperature and alkalinity steel slag were investigated by static crucible method,then the dynamic damage process of MgO-C brick specimens were studied by rotating impregnation method.The damage degree of magnesia-carbon brick specimens were investigated and analyzed.The damage factors of MgO-C brick which were the dipping time,the temperature of molten,the steel slag basicity and the rotation rate of specimens were investigated.Then the orthogonal test was designed and the experiment analyzed the three factors at three levels of magnesia carbon brick samples.Finally,the oxidation which was the main influencing factors lead to damage of MgO-C brick specimens spalling problems were discussed.The corresponding improvement measures were put forward.The results and conclusions were as follows:(1)The slag resistance of magnesia-carbon brick samples were studied at 1550℃ and 1600℃,respectively by the static crucible method.The results showed that the corrosion rate of magnesia-carbon brick samples at 1600℃ was higher,The erosion of the sample occurred mainly at the above 1600℃.At 1600℃,with the alkalinity of 1.3 and 2.1 of the refining slag eroding samples respectively,the results found that low alkalinity steel slag on the magnesium carbon brick specimen erosion was more serious.(2)In the experiment of rotating dipping of induction furnace,it was found that there were three stages of the destruction process of MgO-C brick specimen,The first stage was that the damage index of MgO-C brick specimens increase linearly at the time of 0-1.5 hours,the second stage was that the damage index of MgO-C brick specimens in 1.5-2.5 hours remained unchanged,the third stage was that within 2.5-3.5 hours,the damage index of MgO-C brick specimens increased gradually,but the increase rate was smaller;When the dipping time,rotation rate,slag alkalinity remained unchanged,increasing the temperature of molten steel from 1550 ℃ to 1800 ℃,the temperature of molten steel increased from 1550 ℃ to 1600 ℃,the damage index increased from 2.2mm to 3.5mm,the damage index increased significantly;When the diping time,the temperature and the basicity of the steel slag were kept unchanged,when the rotational speed in the range of 0-57 r/min,the damage index of the sample was the largest at the rotational speed of 57 r/min,this indicated that the greater the rotation rate of samples The more serious the damage;When the diping time,temperature,rotation rate remains unchanged,the alkalinity in the 1.3,2.1 conditions,The most serious corrosion was low alkalinity steel slag.(3)The main reason for the destruction of magnesia-carbon brick specimens by the Induction furnace rotary impregnation method is not only the erosion of steel slag but also is the air.oxidation of MgO-C brick specimen,This is because at high temperature conditions of MgO-C brick at the high carbon content is oxidized layer by layer,this increases the damage gradually.In order to slow down the destruction of the sample of magnesia-carbon brick,the water glass and magnesia fine powder were mixed as a magnesium carbon brick sample coating material,It was found that this method effectively hindered the contact between the air and the magnesia-carbon brick samples and effectively prevented the oxidation of the magnesia-carbon brick samples.The experimental simulation of the damage process of magnesia-carbon brick in ladle slag was carried out by static crucible method and rotary furnace immersion method.It was found that the effect of steel temperature,immersion time,rotational speed and slag basicity by Induction furnace rotary impregnation method could reflect the actual working condition to a certain extent.This could explain the magnesium carbon brick in the actual use of erosion and damage changes in the law.To improve the oxidation resistance of magnesia carbon brick,the surface coating method was discussed,the surface coating method slowed down the MgO-C brick damage.