The corrosion test procedure consists of 3 consecutive cycles. Cycle 1 is to install crucibles in the furnace and fill them with slag. The heating rate is 900° Ch-1 and the temperature is increased to 1600°C. After 2 hours at 1600°C, air quenching was performed for the first time. Because the duration of quenching is limited (40 s), the temperature of helium is not less than 1200°C. The thermocouple is placed 2mm outside the crucible wall, which controls the surface temperature. Cycle 2 is an intermediate step. After the secondary quenching is performed, the slag is replaced this time. Recharge the crucible in the electric furnace in the same corrosive environment at 1600°C. At the end of this stage, secondary air quenching was performed, followed by secondary slag replacement. Cycle 3 is the final stage of the corrosion experiment, quenching the crucible, and then air cooling at room temperature. After the corrosion experiment, the crucible was cut into symmetrical halves, perpendicular to the plane of the inner surface of the original slag-refractory material. Using the original inner surface as a reference point (the initial bottom of the crucible chamber), all the measured data of the infiltration and corrosion of the residual slag were compared to evaluate some of the results of the firebrick. The infiltration zone near the unaffected refractory material is defined as the boundary zone extending from the infiltration surface to the erosion surface. Permeation of liquid oxides through the capillary through the non-chemically reactive open pores invades the ceramic matrix. Therefore, there is almost no change in all the chemical composition of the remaining substances. Penetration and Corrosion Resistance All grades of corrosion tests were evaluated and the results are as follows. G4 (74% andalusite + 12% clay). The properties of the refractory material are used for reference. Corrosion affects it greatly (corrosion thickness: e≈10mm). It was found that G5 (alumina-vazzolite) and G1 (andalusite-white corundum +10% tabular alumina) slag penetration was severe. The permeation zone (thickness: e≈3.5 mm) of G2 (andalusite-white corundum, non-flat alumina) is smaller than G1 (thickness: e≈17 mm). In G2, fine tabular alumina particles were used instead of andalusite to accelerate the penetration of liquid oxides (thickness: e≈3.5 to 17 mm). The G3 (82% andalusite + 4% clay) and G4 firebricks have some minor differences in overall performance, which can be explained by the difference in the content of fine particles of clay and andalusite: in G4, the amount of clay is large (9%), corrosion The intensification and precipitation area decreased, but 5% of andalusite fines (~55m) were added to the G3, and the corrosion decreased and the precipitation zone increased. By comparing macroscopic data of different grades of bricks (permeate thickness + corrosion zone), the following arrangement is obtained: G5>G1>G4>G2 ~ G3. These comparisons show that: G2 (52% andalusite + 30% white corundum) and G3 at the temperature It has good anti-permeability and corrosion under cyclic change. However, G3 is more resistant to penetration. Microstructure analysis The post-mortem analysis by scanning electron microscopy and X-ray powder diffraction clearly illustrates the corrosion mechanism. The corrosion profile observed in the crucible is composed of four structurally distinct juxtaposed regions, and it is easy to identify all of the refractory grades used for the experiment. The "higher-lying zone corresponds to the residue" describes the characteristics of the sedimentation zone by the dissolution of the primary crystal phase and the recrystallization of new minerals. "The slag part infiltrates into the permeate zone, its microstructure and that observed in the original brick. Similar to the "unaffected refractory brick backscattered electron diagram showing the microstructure of andalusite molybdenum brick G4 after corrosion at 1600°C, and shown in the results of the high magnification test of the precipitation zone showing two reactions. The layers are adjacent to each other. The first layer has a thickness of approximately 1 mm and is composed of a well-grown calcium hexaaluminate panel that is unoriented and surrounded by glass and a crystallized calcium silica-aluminate matrix (C2SA). The second layer is slightly thicker, from the self-shaped plate-like crystals and the sub-initial interface Permeation surface Precipitation zone Residue Refractory sample thickness/m □Residue infiltration+Erosion 35302520151050G1G2G3G4G5 Refractory sample thickness/m□ Penetration erosion andalusite diagram a) After corrosion test; b) Penetration and corrosion zones of the same crucible e1: Corrosion thickness; e2: Permeation thickness Impregnation, corrosion, impregnation + corrosion and residual slag thickness measured in G1, G2, G3, G4 and G5 Self-corundum is formed to form a rough three-dimensional structure from which flake-like crystals of calcium plagioclase, calcium aluminosilicate glass and pores can be observed. As the etched surface increases, the pores corresponding to the gas bubble are free. Corundum has a large number of defects in the needle surface, which proves rapid crystallization. These microstructures show the crystallization of calcium plagioclase after corundum. It can be predicted from the ternary phase diagram of CaO-Al2O3-SiO2 that a calcium plagioclase crystal phase is formed during cooling. A series of corrosion products produced by Al2O3/CaO slag on andalusite mullite refractories are: calcium hexaaluminate → corundum → mullite. The microstructure of G5 (Aluminum Vanadium Brick) after etching at 1600°C is shown. Although the corrosion phenomenon is difficult to define clearly, we can clearly recognize the continuous regions similar to those observed in andalusite bricks. A high-magnification test of the precipitation zone shows a single mineral layer of different calcium di-aluminates, calcium hexa-aluminate, and corundum, and a series of corrosions are calcium di-aluminate→calcium hexaaluminate→corundum. The dividing line between these three layers consists of a very irregular surface. The intercalation of calcium di-aluminate and calcium hexa-aluminate layers with their hexagonal calcium hexaaluminate crystals seems to replace calcium di-aluminate crystals. Similarly, calcium aluminate crystals containing corundum instead of alumina crystals. The lower interface of the precipitation zone (corundum crystal) cannot be clearly marked and passes through the impregnation zone where it can be discerned that the phantom shape of the initial alumina-vanadium particles has changed to corundum. These alumina-vanadium particles are in corundum microspheres. The large density of the crystals and the appearance of Al2TiO5 with some Fe2O3 are used to describe its characteristics. The small space between crystals is invaded by vitreous and calcium plagioclase. The amount, composition and viscosity of the liquid phase were evaluated by the ternary phase diagram of CaO-Al2O3-SiO2 after energy dispersion analysis and local thermodynamic equilibrium rules, and the liquid phase amount and composition at 1600°C and the initial slag-refractory material were obtained. The function of the distance between inner surfaces. Based on the Urbain semi-empirical model, based on its composition, the viscosity of the liquid phase is calculated using the formula ATexp(103B/T), where A and B are the two parameters of the vitreous component. All test masses, component profiles, proportions and viscosities of the liquid phase at 1600°C were confirmed by approximations. For example, the component corridors of G4 and G5 (as a function of the distance between the chemical composition and the initial slag-refractory inner surface), the amount and viscosity of the intergranular-liquid phase are shown in Fig. 9, and these figures show: The composition of the liquid phase in the remaining slag and unaffected zones is a constant "through the improved zone (zones II and III), where a concentration gradient appears in the liquid components, thereby leaving the unaffected refractory interstitial fluid components Connected to the interstitial liquid component of the slag, "The inter-grained liquid phase contains more silicon oxide than the refractory material. Silicon oxide migrates from the refractory material to the slag. This can be explained by the increase in the amount of silicon oxide, and the alumina and oxidation. Calcium reduction With regard to G5 bricks, there is no residual slag zone in it, and the liquid phase viscosity of the improved part of the bauxite refractory is lower because of the appearance of secondary elements such as Fe2O3, TiO2, and basic oxides. This explains why the bauxite deposit area is wider than the andalusite deposit area . Bathtub Drain, Basin Drain, Shower Floor Drain, Kitchen Sink Drain ZHEJIANG KINGSIR VALVE CO., LTD. , https://www.kingsir-valve.com