Baking Requirements of Refractory Cement

The production of refractory cement is not a simple matter. There are many requirements. Only by mastering these requirements can we bake cement that meets the requirements. Therefore, we need to master the baking requirements of refractory cement. The introduction of the editor is as follows:

1. Refractory cement refers to cement with a refractoriness not less than 1580°C. Refractory cement uses bauxite and limestone as raw materials, and is calcined to obtain clinker with calcium aluminate as the main component and about 50% alumina content, and then ground to produce a hydraulic cementing material. According to different composition, it can be divided into aluminate refractory cement, low calcium aluminate refractory cement, calcium magnesium aluminate cement and dolomite refractory cement. Refractory cement can be used to cement various refractory aggregates (such as corundum, calcined high alumina bauxite, etc.) to make refractory mortar or concrete, which is used as lining in cement rotary kilns and other industrial kilns.

2. The 350 ℃ stage at room temperature is most likely to cause local bursts. Pay special attention to slow baking. If there is still a lot of steam coming out after heat preservation at 350℃, the heating speed should still be slowed down. Under the conditions of poor ventilation and difficult to discharge water vapor, the heat preservation time should be extended appropriately. When baking with heavy oil, it is necessary to prevent heavy oil from spraying on the surface of the furnace lining to prevent local bursting.

3. When using wood to bake, direct contact with the flame will often cause local heating up too quickly, which should be protected. For the newly poured refractory cement, it (Highaluminarefractory.com/high-alumina-refractory-cement/) can be baked at least 3 days later. Cooling of the refractory cement lining should also be slow to avoid forced ventilation.

4. Refractory cement fineness: the finer the cement particles, the larger the specific surface area, the faster and more fully the hydration reaction, and the higher the early and late strength. National regulations: The specific surface area should be greater than 300 square meters per kilogram, otherwise it is unqualified.

5. Setting time of refractory cement: In order to ensure that there is sufficient time to complete various processes such as mixing, transportation, and molding during construction, the initial setting time of cement should not be too short; after construction, it is hoped that the cement can harden as soon as possible to produce strength. Therefore, the final setting time should not be too long. The initial setting time of refractory cement shall not be earlier than 45 minutes, and the final setting time shall not be later than 390 minutes.

6. Volume stability of refractory cement: The uniformity of volume change of cement paste during the setting and hardening process is called the volume stability of cement. If the volume changes unevenly, the volume stability is poor, which is prone to warping and cracking, which reduces the quality of the project and even causes accidents.