This paper introduces the running characteristics and rules of the trend chart of Maerz kiln. Through analysis on trend chart curve, the effective judgments on a series of problems in daily production operation are made to better serve the field production.

In the development of chrome free process of refractory materials used for RH refining furnace,magnesium aluminum spinel non-fired bricks have been tested as the best alternative products for electrofusion and recombination of magnesium chromium bricks.Through static crucible test,the slag resistance experiment is carried out on the MgO-MgAl2O4-Al composite material and the residual bricks used in the RH furnace are compared and analyzed.It is found that the slag layer,the erosion layer and the original brick layer form both in the crucible and the residual brick of the RH furnace during the slag resistance test.The microstructures of the slag layer,the erosion layer and the original brick layer are analyzed by scanning electron microscope.It is found that the microstructure of the crucible in slag resistance test under laboratory conditions is different from that of the residual brick on site.The results show that firstly the slag layer,the erosion layer and the original brick layer form in the residual brick used in RH furnace,and the phases in the slag layer are mainly periclase,magnesium aluminum spinel,iron oxide solid solution and calcium aluminate phase,secondly a dense periclase zone forms in the erosion layer,thirdly Mg-A1-(Si)-O-N non-oxide forms by the reaction of aluminium powder with MgAl2O4 and MgO,which is analyzed on residual bricks used in the RH furnace and improves the slag resistance.The MgO-MgAl2O4-Al composite has a good anti-slag resistance in the hot parts such as RH furnace trough,impregnated pipe and circulation pipe.

This paper introduces the factors and control essentials of crack generation in the sintering process of magnesian sliding plate.After adjusting the sintering process schedule and optimizing the loading ways of the sliding plate in the kiln car,the length and width of the sliding plate crack decrease,and the qualified rate has been raised from 80% to over 98%,greatly reducing the production cost.

In view of the low self-opening rate of the steel ladle in the second district of steelmaking department,various reasons analysis and research  are carried out,and the key factors such as the  material of ladle filler sand,the shape of the pocket blook and the control of the production are both improved,and the problem of low self-opening rate is finally solved.

This paper studies the failure of high chrome brick used in opposed four-nozzle gasifier.The scan electron microscopy (SEM) analysis result shows that firstly there is almost no slag in the interface of slag/brick of high chrome brick and a  ZrO2-free layer with a depth of about 3 mm under the interface,secondly the FeO in slag reacts with the Cr2O3 in brick to form ferrochrome spinel (FeCr2O4),which focuses in the ZrO2-free layer interface,thirdly the SiO2 and CaO of the slag infiltrate deep into the brick and react to form low melting point material mainly such as calcium aluminum silicate and a small amount of calcium phosphate,and finally the failure forms of high chrome brick used in gasifier are mainly infiltrated erosion and spalling.

This paper introduces the significant effect of sepiolite as an efficient environment-friendly heat-preservation material on coke oven of Laiwu steel,and the  effect of raising end flue temperature by heating with blast furnace gas.