Notes for medium-grade magnesia

Notes for medium-grade magnesia:

Oxidation resistance: Carbon composite refractory has excellent thermal shock resistance and slag resistance due to the existence of carbon, but it has the defect of easy oxidation. Once carbon is oxidized, its advantage will be lost. In order to give full play to the advantages of carbon composite refractories, the antioxidant properties of carbon composite refractories are often improved by adding appropriate additives. Due to its active performance and easy reaction with O2 and CO, metals have been used as antioxidants in refractories. Al, Si, Mg and corresponding alloys are commonly used as antioxidants.

In situ reaction to produce non-oxide: introduce the metal into the refractory material and use it to react with the raw material components or the surrounding gas in the firing process to produce non-metallic reinforced and toughened phase, which can improve the performance of the matrix at room temperature and high temperature as well as thermal shock resistance. At present, this technology has received extensive attention.

It can be seen from the above that the addition of metals to refractories has played a positive role in the mechanical properties and antioxidant properties of refractories, which indicates that they have a broad application prospect in refractories. With the continuous development of science and technology and the continuous breakthroughs in the field of science, the performance of metal composite refractory materials will be continuously optimized and its application scope will be further expanded.

1, mold: made of steel plate or hard wood, steel plate coating agent (oil), the board coated with waterproof paint, should be done not leak, and a good strength.

2, mixing: with the blender, first pour the pouring material into the blender, and take out the additives to add, first dry mix 2-3 minutes, then add water to mix 3-5 minutes, add water should not be more or less.

3, vibration: into the mold of the pouring material, immediately ramming must not leak to a certain position, also can not be the same position ramming, in order to avoid the segregation of the pouring material and holes, mixing good pouring must be from the water to use up in 20-30 minutes, the initial setting to abandon.

4. Curing: The mold can be removed only after the surface of the pouring material is dry and reaches 70% strength. The curing time is 24 hours and 48 hours.

5. Oven: According to different brands, castable lining thickness and climatic conditions, the user must ensure adequate baking time of 72 hours.