Study Of Influence Of Molten Iron Slag Carbon Brick Erosion Of Blast Furnace Hearth

At present,iron and steel production in China is mainly based on the long process of blast furnace-converter.With the increase of iron and steel production,blast furnace,as a production equipment for reducing iron ore into hot metal,is still one of the most efficient,low-consumption and environmentally friendly ironmaking equipment.With the continuous increase of smelting intensity,hundreds of blast furnaces need safety maintenance every year,which greatly hinders the development process of safe and long life production of blast furnaces.The longevity of blast furnace has always been the goal pursued by metallurgical workers.The hearth is equivalent to the heart of the blast furnace and is also one of the limiting factors for the longevity of the blast furnace.The blast furnace hearth is in the lower part of the blast furnace.Because the side wall of the hearth is eroded and scoured by the slag iron circulation for a long time,the hearth becomes the limiting link of the blast furnace longevity.In this paper,the effects of molten iron elements and molten iron circulation on the erosion of carbon bricks were studied by using the rotating finger bar method.The conclusions are as follows:C and Si elements in molten iron delay the erosion rate of carbon bricks,and the influence degree is C>Si;Mn,P and S accelerated the dissolution of carbon bricks,and the degree of influence is P>S>Mn.With the increase of C content,the weight loss rate has no obvious rule.The weight loss rate of carbon bricks increases with the increase of Mn,P and S elements.The slag-iron circulation affects the dissolution reaction of carbon bricks.The greater the sample rotation speed,the higher the erosion rate and weight loss rate of carbon bricks.The mechanism of carbon brick dissolution is expounded from the perspective of kinetics,and the reason is that the dissolution of ASC brick is mainly controlled by C.The dissolution of carbon brick in molten iron is a typical solid-liquid heterogeneous reaction,and the vortex around the cylinder is in the transition from laminar flow to turbulent flow.By means of XRD and SEM-EDS,the erosion of carbon bricks was analyzed from two aspects:molten iron element and slag iron flow rate.C and Si elements reduce the infiltration of C elements in molten iron to varying degrees,and delay the erosion of carbon bricks.With the increase of Mn,P and S elements in molten iron,the erosion severity of carbon bricks is increasing.Through XRD and SEM-EDS analysis methods,the erosion of carbon bricks by slag iron flow rate was analyzed.The rotation speed affects the strength of the element peak.The higher the rotation speed,the stronger the peaks of C,Al₂Si O₅and other elements.The slag-iron protective layer was detected by SEM-EDS,and with the increase of rotational speed,the cracks and holes of the carbon brick after erosion increased,and the iron content gradually decreased from the hot surface to the inside,while the carbon content gradually increased.