Low cement castables are mainly used in aluminum melting furnace static furnace walls, furnace tops, furnace bottoms, aluminum water ladles, chutes, smelting equipment, high-temperature furnace linings, heating furnaces, soaking furnaces and other heat treatment furnaces. But what should be paid attention to when using it? Relevant personnel of the company gave instructions:
1. How to use low cement castables
1. Stirring: The use of clean water is a basic requirement during the preparation process, as impurities and contaminants may affect the performance and durability of the material. At the same time, it is also necessary to control the water temperature within the range of 10 to 25°C to avoid problems caused by rapid evaporation of water or excessive material temperature gradient. Before mixing, the ingredients must be strictly followed according to the mix ratio given in the material instruction manual. In order to overcome the uneven particle size distribution that may occur during transportation of dry aggregate, dry mixing should be performed for 1 minute first. This allows the aggregates to be initially mixed evenly and lays a good foundation for subsequent addition of water. The stirring time after adding water should be controlled at 4 to 5 minutes to ensure that each component is fully moistened, evenly mixed, and reaches the required consistency and fluidity.
2. Pouring: In the construction process of refractory low cement castables, precise operating steps are crucial. First of all, the fully mixed and evenly mixed castables are quickly transported to the construction site, which is the key to ensuring the freshness of the materials and the continuity of the construction. After arriving at the site, the construction workers used spades and special hoppers to accurately pour the castables into the pre-prepared molds.
3. Formwork removal and repair: At this stage, careful inspection of the pouring quality is crucial. General defects, such as minor cracks or unevenness, usually do not have a serious impact on overall performance and therefore do not usually require special treatment. However, when major defects are found in key parts or are found, they must be repaired immediately to ensure that the refractory castable can meet the strict requirements of the production process.
2. Precautions for using low cement castables
1. Prepare castables according to proportions: During the preparation process, the corresponding proportions must be strictly followed to avoid adding water at will or adding too much castables. Improper proportions will directly affect the fluidity, solidification time and final strength of the castable, thereby significantly reducing its use effect.
2. Use the evenly stirred castable as soon as possible: the evaporation of water will not only reduce the moisture content of the low cement castables, but may also affect its subsequent solidification and performance.
3. Castable materials should be stored dry
4. Develop a reasonable oven curve: ensure that the temperature gradient is gentle during the baking process and the moisture can be discharged evenly. When necessary, special explosion-proof additives can be used to enhance the crack resistance of the material and reduce possible risks during the baking process.
