Everything you need to know about refractory cement is hereDate: 2019-06-13 Views:
Therefore, refractory cement refers to cement with a refractoriness higher than 1580℃.It can be divided into aluminate refractory cement, low calcium aluminate refractory cement, calcium magnesium aluminate refractory cement and dolomite refractory cement.Refractory cement is widely used, which can be used to cement various refractory aggregates (such as corundum, calcining high-alumina, etc.), to make refractory mortar or concrete, and used as lining of cement rotary kiln and other cement production equipment.
Refractory cement baking:
Attention should be paid to the following matters when baking refractory cement lining:
1) at the stage of 350 ° c at room temperature, local bursting is most likely to occur, so slow baking should be paid special attention to.
If there is still a lot of steam after 350 degrees heat preservation, still should slow down the heating rate.
2) under the condition of poor ventilation and difficult discharge of moisture, the insulation time shall be appropriately extended.
3) when baking with heavy oil, it shall be strictly prevented from spraying heavy oil on the lining surface to prevent local burst.
4) when using wood to bake, direct contact with the flame will often cause excessive local heating, should be protected.
5) bake newly poured refractory cement at least after 3d.
6) cooling of refractory cement lining should also be slow to avoid forced ventilation.
1. Fineness: the finer the cement particles are, the larger the specific surface area, the faster and more complete the hydration reaction, and the higher the early and late strength.
The country stipulates: specific surface area should be more than 300 square meters/kg, otherwise it is unqualified.
2. Setting time: in order to ensure sufficient time to complete mixing, transportation, molding and other processes during construction, the initial setting time of cement should not be too short;
After the completion of construction, it is hoped that the cement can harden and produce strength as soon as possible, so the final setting time should not be too long.
The initial setting time of Portland cement shall not be earlier than 45 minutes and the final setting time shall not be later than 390 minutes.
3. Volume stability: the uniformity of volume change of cement paste during setting and hardening is called volume stability of cement.
If the volume change is not uniform, that is, the volume stability is not good, easy to produce warping and cracking, reduce the project quality and even accidents.
After understanding so much knowledge about refractory cement, I believe you have a more clear understanding of the use of refractory cement, to provide help for you to use cement products!