AOD furnace leaves an operation in the slashing condition with long high temperature, lining life, outside be being concerned except the sort with fireproof material, quality, still get the amount of wind gun, distributing reach eject gas craft, the time that keeps below the peak value temperature of molten steel and this temperature is concerned. Be built as to the street of lining and repair a method, and heat preservation is roast system, or the element such as time interval has two stove the influence of certain level. To improve lining life, more significant step is as follows:
(1) pledges in material respect, in order to because of,raise AOD furnace of low basic slag fight aggressivity and wear-resisting caustic sex to be a purpose, developed Gao Ge content of; of qualitative magnesian chromic brick is bigger, be able to bear or endure the sex that invade chaotic is better, cr203 content with 18% advisable, but constituent of the flux in following a brick (SiO2, Fe2O3, CaO) increase, be able to bear or endure aggressivity has downtrend. Accordingly, control matter content strictly, already began to use the raw material of tall chromic concentrate of low SiO2 partly now. On the other hand, consideration environment pollutes a problem, the development application of the brick that do not have chromium is very pressing. Current, magnesian qualitative, magnesian calcium reachs his character goods of low carbon content is used at finery to already had improvement greatly.
(2) uses area build by laying bricks or stones to build bricky method. Because the attaint of AOD furnace has regularity, concentration is all round blast tuyere, broken bits line and trunnion, introduce line of area build by laying bricks or stones by the place that erodes degree to differ, tall erode an area (all round blast tuyere) use frit bead recombine magnesian chromic brick. Low wear away area (tapping mouth) periphery of line of job of chromic brick bottom uses the direct union magnesium that uses MgO60% magnesian chromium pounds dozen of makings character make, the direct union magnesium that safe line and side wall use 60%MgO is chromic brick, side wall brick for arch model, wedge and straight form, ash is seamed use alkalescent fireclay. Normally Zuo uses the cap of cricoid coping furnace of mouth tall aluminium but plastic build, originally closely with iron plate inside cap mouth, in order to maintain its pouring the appearance of makings, use ply to differ the AOD furnace that build by laying bricks or stones of the belt that reach cent builds, obtained balanced corrode caustic and good use the effect.
(3) commands the influence of the pressure of air current and discharge. All round blast tuyere of fireproof material erode, basically be caused. Increase when air current pressure, when discharge increases, the phenomenon with this kind of regressive bleb disappears. The lining life of furnace achieves 60tAOD of new Japan smooth factory on average 100 times, analytic result, likelihood and condition of its air feed are concerned, quantity of inbreathe of this furnace gas can amount to 1.0m3/t · Min.
(The life of high temperature body of heater that 4) lowers blowing appropriately is the function that blowing high temperature spends, fireproof material maintains time to grow too in 1700 ℃ above, can make the service life of furnace battle is reduced apparently. Workshop of furnace of an AOD of American considers to discover, raise 10 ℃ when tall blowing temperature, fireproof material life is reduced 30% .
(The influence of 5) slag composition, the strict control of slag is the main factor that improves fireproof material life, from the frit bead recombine after using magnesian chromic brick heats up the chemical composition of the face to analyse a result to see, caO and SiO2 increase significantly, and Cr2O3, FeO and MgO are reduced accordingly. Frit bead recombine is fireproof the main mechanism that material damages in AOD furnace is to corrode, erode in addition, acid slag is right of MgO-FeO photograph preferential erode and of bath backset erosive, infiltration of photograph of silicate low be in harmony is fireproof material hole, those who quickened fireproof material mar. Accordingly, in blowing process, the measure that will raise temperature with silicon at lining it is adverse, those who maintain slag need to shout in using degree, when using dolomite brick especially, more the tall alkalinity that maintains slag.
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