Low cement and ultra-low cement castables have the advantages of high density, low porosity, good hot strength, high refractoriness, and high softening temperature under load. Its erosion resistance is comparable to that of bricks of the same material, the wear rate is also significantly reduced, and the resistance to mechanical spalling and spalling is significantly improved. The technology of Rongsheng Ultra-Low Cement Castable Precast Shapes for Iron Trough is also constantly improving and upgrading, aiming to provide customers with high-quality overall refractory solutions.
Rongsheng Ultra-Low Cement Castable for Iron Trough Precast Shapes
In the production of ultra-low cement castables for iron trenches, premixed powder is used. That is to pre-mix all powders such as admixtures, binders, fine powders, or certain types of powders.
Then the various raw materials are dosed according to the proportion and then poured into a forced mixer for dry mixing. Then add water to stir, stir for 3 to 4 minutes, and then discharge.
When the iron channel is molded with ultra-low cement castables, first place the model on a vibrating table to check the size. Tighten the fixed connectors, and coat the inner surface with oil or stickers. Secondly, put the mixing material into the model and vibrate in time until the surface returns to the slurry and the exhaust is close to the end.
If the particles of the refractory castable are large, the required amplitude is also large. But it should not be too large, otherwise, it is easy to segregate the aggregate. If the amplitude is small, the vibration time should be extended.
Finally, the surface of the Refractory Precast Shapes should be leveled, plastered, marked, and hoisted to the maintenance site. The Precast Shapes of ultra-low cement castables for the iron ditch shall be dried under natural conditions and shall not be sprayed with water. Keep the temperature at 15°C to 25°C, remove the mold after drying for 1 day, and then maintain it for 2 days.
Before the Refractory Precast Shapes leave the factory or build the furnace, they can be pre-baked at 500°C to 600°C to remove the moisture inside the Precast Shapes. This shortens the oven time.
Rongsheng Monolithic Refractory – Ultra-Low Cement Castable
Rongsheng monolithic refractory castable manufacturer has rich experience in the production of monolithic refractory materials through the accumulation of customers’ production needs. In particular, our new monolithic refractory factory will further improve the production of overall refractory materials, and at the same time provide refractory precast shapes for furnaces. Aha, of course, the disadvantages of our existing low-cost cement castables cannot be ignored. Compared with ordinary refractory castables, low-cement or ultra-low cement castables have a series of excellent properties. Mainly manifested in the following aspects.
①. Since the amount of cement added is only 1/2-1/15 of the ordinary refractory castable, the CaO brought into the castable is reduced from 2.5%-8% to 0-2.5%. The amount of eutectic phase formed in the matrix is greatly reduced. Therefore, the refractoriness, high-temperature strength, and slag resistance are all improved. The low melting point decreases at high temperatures, which improves the wear resistance, high-temperature flexural strength, and load-softening temperature of the castable.
②. The amount of water added to the mixture is only 1/2-1/3 (about 5%) of that of ordinary castables. Therefore, the porosity is low and the bulk density is high, which is comparable to the fired refractory products of the same material.
③. The cement hydrate after forming and curing has little or no cement hydrate. When heating and baking, there is no problem that a large number of hydration bonds are destroyed and the strength is affected. Instead, as the heat treatment temperature increases, it gradually sinters and its strength gradually increases. Especially different from ordinary castables, the mechanical strength is higher than the drying strength in the medium temperature zone (900-1200°C). Both high temperature and normal temperature strength are better than ordinary castables.
Unshaped Refractory Materials 