Study On The Foaming Of Titanium-bearing Blast Furnace Slag And The Characteristics Of Hearth Deposits

Vanadium-titanium magnetite is a composite ore with multiple metal elements.At this stage,the blast furnace method is mainly used to treat vanadium-titanium magnetite.After years of surveys in Yangxian County,Shaanxi,abundant vanadium-titanium magnetite resources have been discovered.The vanadium-titanium magnetite belongs to the low-and medium-titanium type vanadium-titanium magnetite.Because vanadium-titanium magnetite has a higher TiO₂ content than ordinary iron ore,problems such as slag foaming and hearth deposits will occur during blast furnace smelting.Therefore,in order to solve the above problems,this article analyzes and understands the research on the foaming of titanium-containing blast furnace slag and hearth deposits at home and abroad.Based on the blast furnace smelting process,the smelting reduction of Yangxian vanadium-titanium magnetite is simulated and carried out in the laboratory.In the high-temperature test,the foam slag and hearth deposits in the middle and low titanium blast furnace were studied.The formation mechanism of the foam slag and deposits was analyzed from thermodynamics and kinetics,and the following conclusions were drawn.The TiO₂ content increased from 7% to 15%,the maximum foaming height of slag increased from 2.65cm to 2.95cm,and the time spent increased from 120s to 165s;the change of alkalinity had little effect on the maximum foam height,mainly because the foam duration changed with Increase with the increase of alkalinity;MgO content increased from 7%to 13%,the maximum foaming height of slag decreased from 2.8cm to 2.7cm,and the time spent decreased from 165s to 150s;FeO content increased from10%to 20%,slag The maximum foaming height of slag increased from 2.7cm to 2.8cm,and the time spent was reduced from 180s to 105s;the higher the temperature,the maximum foaming height of slag increased from 2.7cm to 2.85cm,and the time spent increased from 150s to 180s.The basicity increased from 1.05 to 1.25,the TiC grain size in the slag increased from 3?m to 5?m;the TiO₂ content increased from 7%to 15%,and the TiC grain size in the slag increased from 1?m to 5?m;what was the MgO content in the slag It will not affect the production of TiC;only TiC is produced in an argon atmosphere,and TiC and Ti N are produced at the same time in a nitrogen atmosphere,and the higher the nitrogen content,the higher the proportion of Ti N.The gas source of foamed slag is CO gas generated by the reduction of TiO₂ and FeO in the slag by the carbon in coke and iron,and accompanied by the formation of TiC and Ti N solid particles.These particles change the physical properties of the slag and wet the slag-coke interface.Increase the viscosity of the slag,promote the generation of bubbles,and prevent the bubbles from overflowing,resulting in foamed slag.The reaction of TiC and Ti N proceeds in the forward direction in the blast furnace.Under the conditions of a strong reducing atmosphere in the blast furnace,and when there is more coke and nitrogen,TiC and Ti N will be simultaneously generated under certain conditions.Homogeneous nucleation occurs easily at higher temperature and higher a _TiO2;it is easy to generate TiC and Ti N by heterogeneous nucleation on the graphite surface.