Steel fiber reinforced corundum and high-alumina refractory castables for rotary kiln mouths are prone to cracking and peeling after many years of use, that is, poor thermal shock resistance and low service life. It is well known that clay bricks are better than high-alumina bricks in thermal shock resistance and alkali resistance because of low aluminum content; high strength, good wear resistance, and poor shock resistance. In the castables for kiln mouths, the Al2O3 content is 50% to 70%, the strength is moderate (taking into account both wear resistance and suitable thermal shock resistance), and the drying and compressive strength (1100℃) are about 40MPa and 70MPa respectively. It should be pointed out that refractory castables are composed of aggregates, powders, binders, and admixtures (substances). The phase composition in the matrix is in a non-equilibrium state before use. When used under high temperatures, the components in the matrix will follow the phase equilibrium relationship to re-form a new phase equilibrium (that is, obtain excellent performance and in-situ reaction). Therefore, suitable component materials should be selected and the batch design should be optimized to achieve good sinterability, volume stability, corrosion resistance, and high-temperature mechanical properties. Selection of main materials The front kiln...

As a high-performance refractory material, chrome corundum bricks are mainly used in industrial fields that need to withstand high temperatures, high pressures, and corrosive environments. Their excellent fire resistance, flexural strength, high-temperature creep, high-temperature volume stability, and corrosion resistance make them a key component in many industrial furnaces. The following are the main areas of application of chrome corundum bricks: 1. Metallurgical industry Steel smelting: Chromium corundum bricks are widely used in rolling heating furnaces in the steel industry, especially in parts prone to wear such as slide rails, tapping channels, and grooves. Its high wear resistance and long life (up to 10 to 18 months) significantly reduce refractory materials’ consumption and maintenance costs and increase the furnace’s overall life and output value. Non-ferrous metal smelting: In the process of non-ferrous metal smelting, chrome corundum bricks are used as linings for copper smelting furnaces, zinc smelting electric furnaces, and other equipment due to their superior wear resistance and corrosion resistance, effectively resisting high-temperature melts and corrosion—the erosion of sexual atmosphere. 2. Petrochemical industry Chrome corundum bricks also have important applications in gasifi ers in the petrochemical industry. These gasification furnaces have been exposed to high temperatures (1350~1450℃), high pressures (3.1~8.53MPa),...

There are significant differences between alkali-resistant castables and high-aluminum castables in many aspects. These differences are mainly reflected in composition, performance, use, and structural characteristics. 1. Differences in ingredients Alkali-resistant castable: The main components are MgO, MgO-Al2O3, MgO-CaO, MgO-CaO-SiO2, etc. These ingredients give the alkali-resistant castable excellent alkaline corrosion resistance. High aluminum castable: The main component is Al2O3, and the high alumina content makes it perform well in high-temperature environments. 2. Performance characteristics Alkali-resistant castable: It has high strength, alkali resistance, and excellent corrosion resistance. It can withstand the erosion of various slag materials, such as slurry, molten slag, limestone, etc., without causing erosion. At the same time, alkali-resistant castables also have good alkali-resistant aggregate reaction properties, thermal shock stability, wear resistance, and air permeability. High-aluminum castables: famous for their excellent high-temperature resistance, thermal shock resistance, chemical erosion resistance, and load resistance. At high temperatures, high-aluminum castables will not expand, crack or soften, and can withstand changes such as alternating hot and cold, rapid heating, and rapid cooling. In addition, its structure is dense, able to withstand various loads and vibrations, and is not prone to problems such as cracks and collapse. 3. Different uses Alkali-resistant castables: widely used in...

When comparing the density of high alumina cement and aggregate, we need to clarify the physical properties of the two and their respective density ranges. 1. Density of high alumina cement The density of high alumina cement, also known as high alumina cement, is a basic physical parameter of cement materials. According to information from different sources, the density of high alumina cement is usually between 2.9~3.0g/cm³, which is similar to the density of common cement types such as Portland cement. High alumina cement is widely used in construction and industry due to its excellent fire resistance, corrosion resistance, and fast setting time. 2. Density of aggregate Aggregate, as an important component of concrete, has an important influence on the performance of concrete. The density of aggregate varies according to its type and characteristics. Generally speaking, aggregate can be divided into ordinary aggregate, light aggregate, and heavy aggregate. The density of ordinary aggregate is roughly 2500~2700kg/m³; the density of light aggregate is lower, usually between 0~1000kg/m³, such as ceramsite, expanded perlite, etc.; while the density of heavy aggregate is higher, which may reach 3500~4000kg/m³, such as iron ore, barite, etc. 3. Density comparison From the absolute value point of view,...

There are many reasons why corundum refractory castable is so expensive. Usually, its price is 2-3 times higher than that of ordinary high-alumina bricks. So what are the reasons for its high price? Today, the editor will give a brief introduction: 1. High cost of raw materials The raw material of corundum refractory castable is mainly corundum. Corundum is a high-purity, high-quality refractory mineral. Its mining and purification process is relatively complicated. Not only that, the alumina content in corundum bricks generally needs to reach more than 90%, which requires the purity of corundum to be high enough to meet this standard. At present, my country’s corundum storage resources are relatively small, and the mineral content in the ore is relatively low. At present, artificial corundum is still the main one used on the market, so the cost of corundum raw materials remains high. 2. Complex production process The production process of corundum refractory castables is relatively complex and generally has high requirements for the process. Only in this way can the standard of more than 90% content be met, and the proportion of corundum refractory castables also needs to be very precise, so producers need to invest a lot...