Corundum and spinel castable and preparation method thereof

Abstract

The invention relates to corundum and spinel castable and a preparation method thereof. According to the scheme, the method comprises the following steps of: blending 1 to 10 weight percent of magnesia-alumina spinel fine powder, 5 to 10 weight percent of white fused corundum fine powder, 5 to 10 weight percent of alpha-Al2O3 micro powder, 2 to 8 weight percent of pure calcium aluminate cement, 0.06 to 0.2 weight percent of poly carboxylic acid water reducing agent, and 0.01 to 0.1 weight percent of organic fiber, and precasting mixed powder; performing dry-blending on 6 to 18 weight percent of partially stable zirconia particles or calcium zirconate particles, 45 to 70 weight percent of tabular corundum particles and 1 to 10 weight percent of magnesia-alumina spinel particles which are used as aggregate for 4 to 6 minutes, adding the mixed powder, and milling for 15 to 30 minutes; and adding water in an amount which is 3 to 6 percent based on the weight of the mixed powder and aggregate, milling for 3 to 5 minutes, vibrating and performing casting moulding, curing for 20 to 26 hours, demoulding, drying at the temperature of between 100 and 120 DEG C for 20 to 26 hours, raising temperature to 1,450 to 1,750 DEG C, and preserving heat for 2 to 4 hours. The prepared corundum and spinel castable is high in thermal shock resistance, high-temperature strength, and strength retention rate after thermal shock, and long in service life.

Description

technical field [0001] The invention belongs to the technical field of refractory materials, and mainly relates to a corundum spinel castable and a preparation method thereof. technical background [0002] Corundum spinel castables have excellent high temperature strength, slag erosion resistance and spalling resistance, and are widely used in parts with harsh conditions in ladles (such as ladle lining, air brick system and ladle bottom impact zone, etc.). With the improvement of smelting technology, especially the rapid development of refining technology outside the furnace, the use environment of corundum spinel castables is becoming increasingly harsh, mainly manifested in the concentration of thermal stress. changes, and the large temperature difference between the air channel and the area away from the air channel causes thermal stress in the material. In addition, due to the high service temperature, the high temperature strength of the material is generally lower th...

AI Technical Summary

Problems solved by technology

[0003] There are many ways to improve the thermal shock stability of castables, but the normal temperature strength and high temperature strength of the prepared castables have decreased, such as: "containing nano-magnesium carbonate The corundum-spinel castable” (ZL200910064482.6) patent technology, the castable produced has good fluidity and construction performance, but the decomposition of magnesium carbonate reduces the compactness of the material on the one hand, and reduces the hardness of the material on the other hand. Strength, especially high temperature strength; "Thermal Shock Resistant Corundum-Spinel Castable" (ZL200910180707.4) patent technology mainly introduces monoclinic ZrO2 The microcracks after phase transformation are toughened, but the size of the cracks after the phase transformation is difficult to control, and the bonding interface with the matrix is ​​poor. When the temperature changes sharply, the microcracks expand rapidly without effective barriers, destroying the material. The microstructure deteriorates its mechanical properties. According to the research of Jia Quanli and others, the introduction of ZrO2 will reduce the sinterability of the material and reduce its performance, and the high temperature flexural strength at 1600 ° C will decrease [Jia Quanli , Ye Fangbao, Zhong Xiangchong. Effect of ZrO2 Addition on Properties of Corundum-Spinel Castables[J]. Refractories, 2009, 43(1): 27~30]

[0004]In addition, the introduction of substances that can promote sintering in some castables, although increasing the density of the material, cannot improve the thermal shock stability of the castable, such as : "A high thermal shock corundum-spinel refractory and its preparation method" (ZL200610053302.0) patented technology, introducing TiO2 into the castable, although it promotes the casting of magnesium aluminum spinel The densification effect during the sintering process of the castable has a certain effect on the thermal shock stability, but according to the research of Jia Quanli et al., the addition of TiO2 has little effect on the thermal shock stability of the castable , and has an adverse effect on the high temperature flexural strength. In addition, when the amount of TiO2 is too large, it will reduce the room temperature strength of the lower castable [Jia Quanli, Ye Fangbao, Zhong Xiangchong. TiO2 Effect of sub>addition amount on properties of corundum-spinel castable[J]. Refractories, 2009, 43(6):417~421]