How to improve the quality of magnesia refractory bricks?

The important way to improve the quality of refractory materials is to increase the purity of refractory bricks, reduce the number of low melting materials, and increase the density and high temperature intensity of refractory bricks. High -density magnesium refractory materials and high purity are directly combined with magnesium refractory materials. It is an important trend of the development of magnesium refractory materials at home and abroad in recent years.

(1) High -purity raw materials, high -pressure molding, high temperature firing and meaning

A basic experience in the production of refractory materials is based on concentrate, that is, high purity. The melting impurities content has a great impact on the resistance and high temperature strength of the furnace lining brick. And directly affect the life of the furnace.

The purpose of high -voltage molding is to increase the strength and density of refractory bricks. The larger the density of the brick, the more difficult it is to penetrate in the brick.

High -temperature firing is a measure to achieve fully sintering on the basis of high -purity raw materials. Under the conditions of the liquid phase, it can form a so -called direct binding structure in the brick, while increasing the density of refractory bricks and increasing the high temperature intensity of the brick. It should be said that the increase in high temperature intensity of refractory bricks is a comprehensive result brought by factors such as decreased impurities, high -pressure molding, and high temperature firing. Tests and experiences show that the high temperature intensity of bricks can predict the ability of tile resistance to the abrasion of waste steel.

(2) Composition of brick making

① Control the ratio of C / S. The smaller the CAO / SIO2 ratio, the second priority of coexisting with the main crystal of magnesium in the magnesium refractory material is mainly based on low -melting points such as calcium magnesium olives and iron rose pyroe. Increasing the CAO / ratio, there is a high -melting point mineral with calcium silicate and triglymer. Therefore, the high temperature intensity of the secondary relative to the brick outside the magnesium has a great impact. The ratio of the CAO / SIO2 of magnesium bricks shall be controlled within the best range of the maximum value. Otherwise, a low melting point silicate will be formed to significantly decrease the intensity. From the perspective of slag resistance, the high CAO / SIO2 value is also necessary, because when the turntable is used, CAO / SIO2 is better than that of magnesium bricks with high magnesium bricks.

② Reduce the melting effect of the B2O3. This is a problem brought by the use of seawater magnesium.

③ Adjust the mineral composition of the fire -resistant brick, increase the start temperature of the liquid phase, and reduce the amount of liquid phase at high temperature.

The use of high -purity raw materials, high -voltage molding, and high -temperature firing can significantly improve the quality of refractory materials. However, this is often subject to cost constraints. In terms of improving the quality, the method of practical significance is to understand the role of low melts, so as to control it and reduce its harmful impact. This can start from two aspects: avoiding low melting materials, that is, increase the start temperature generated by the liquid phase and reduce the amount of liquid phase at high temperature; control the distribution of liquid phases, so that the hydraulic phase does not surround the refractory solid phase particles, and the hydraulic phase is not surrounded by refractory solid phase particles. It is excluded in the particle gap, so that the liquid phase will not penetrate the particles, so that the solid -phase particles will be increased without the touch and achieve a direct combination.

(3) The structure of controlling refractory materials

The so -called structural control is both distributed in objects in refractory materials. The practical significance of this research work is developed from the so -called directly combined with the emergence of magnesium chromium bricks. When high temperature, the liquid phase tends to move the particle clearance instead of surrounding particles, forming a direct combination of solid -phase particles.

① Among the magnesium bricks containing MGO and liquid -phase under high temperature, in order to increase the direct combination of Fang Magnesteentestone, or the liquid phase does not cause the magnesium granules to penetrate the magnesium. Then it is very beneficial to add CR2O3.

② Materials (such as white cloud stone bricks, magnesium chromium bricks, or chromium magnesium bricks) have the combination of different particles than the same particles at high temperature at high temperature. Therefore, it is very favorable to use spinel or M2S and C2S high -melting points as a secondary direct combination.


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