Refractory castables are divided into acidic, alkaline, and neutral castables according to their chemical resistance; they are divided into heavy castables and light castables according to their bulk density; they are divided into aluminum silicate, magnesia, and magnesium chromium according to the materials used Quality, corundum castables, etc. There are many types, and it is difficult to make a choice without clear indicators and operating temperatures.
The following is about the correct selection of refractory castables:
The castable must meet the requirements of the furnace
Refractory castables have certain use positions and use requirements, which should be selected according to the characteristics of the castable. For example, high temperature resistant castables should be selected for parts contacting high-temperature flames, high-temperature resistant and permeable castables should be selected for parts contacting high-temperature solutions, and castables with strong resistance to chemical corrosion of slag should be used for parts contacting slag. High-strength and wear-resistant castables are used for parts that are exposed to impact and friction of various materials, and castables with excellent thermal shock resistance are used for parts with frequent temperature changes. The main conditions of use must be met when selecting.
The main use parts of lightweight refractory castables are heat insulation, lower load-bearing structure, lower furnace shell temperature, and reduce heat loss, so as to achieve energy-saving effects.
Consideration of the cost of refractory castables
After deciding which refractory castable to choose, the cost should be reduced economically. If the use temperature is 1500℃, when the castable can meet the working conditions, the castable with the use temperature greater than 1600℃ is not selected; the wear-resistant part adopts high bauxite clinker as the main material to meet the In the case of abrasive requirements, do not choose the castable with corundum as the main material. The main reason is that the price of refractory castables is priced according to the content of the main materials used, and the price varies greatly. There is no need to ignore economic conditions in order to seek higher quality. Especially the parts of daily wear and tear are particularly important to this requirement.
Granularity selection of refractory castable
The parts used for refractory castable construction are thick or thin, and the particle size ratios used are also different. For example, for linings with a thickness greater than 100mm, more large-grain aggregates need to be added to improve structural strength and wear resistance. For pouring or smearing parts with a thickness of 10mm, use less large-grain aggregates. Avoid adding The large aggregate makes it protrude from the lining body, which not only affects the appearance, but also the large particles are easy to wear in the use effect, which is easy to cause pits in the lining body, which affects the service life. Pouring method or smearing method can be used for different pouring thickness, so the choice of the particle size of refractory castable is also very important.
The shelf life of refractory castables
Refractory castables can be stored for about 6-9 months in a dry state. Check whether there is agglomeration before use. During transportation or handling, the castable will agglomerate due to the squeezing effect, and can be easily discharged without affecting the use effect. In actual production, most of the castables are out of stock because of the different configuration processes of the castables. All need to produce according to the needs of users and adjust the production process.
It can be seen from the above that the choice of refractory castables is changeable and should be used flexibly. If you want to quickly and accurately choose the castable you need, you must understand the specific use position, working condition, use temperature, pouring thickness and construction method of the castable. Only by finding the right method can we choose high-quality refractory castables while reducing costs.
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