EN
Lightweight expanded clay aggregate or ceramsite, also called LECA, is a flexible substance in lightweight concrete, geotechnical fill and water filtration. But not every ceramsite has such a high degree of strength and durability. Ceramsite of high strength is a material that must be closely controlled in terms of the choice of raw materials, the parameters of processing, and quality control. Hebei Runhuabang New Material Technology Co., Ltd. is a company that deals in crushing, processing and distribution of non-metallic minerals such as LECA and other aggregates. Through complete exploitation of local geographical and resource superiority we make industrial buyers realize what we put in making ceramsite that can work reliably in harsh conditions.
Raw Material Selection for High-Strength Ceramsite
Raw material is the cornerstone of high strength ceramsite. Majority of ceramsite is made using natural clay, shale or silt that swells upon heating. Silica and alumina are the most important chemical materials that create a viscous glassy phase during firing. Iron oxide is a fluxing agent which facilitates melting and gas formation. The raw materials used in high strength products should be of uniform composition with regulated amounts of fluxing agents. Excessive flux leads to excessive melting and poorly bloated particles. Excessively small flux leads to a lack of expansion and thick and heavy aggregate. Hebei Runhuabang New Material Technology Co., Ltd. has access to raw materials from deposits with known, consistent chemistry, which are processed to achieve the right balance between expansion potential and fired strength.
Crushing and Milling for Uniform Particle Preparation
Raw materials should be ground into a fine powder with uniform distribution of particle size before expansion. This is a critical step since the size of the particles varies and this causes uneven expansion and weak spots in individual ceramsite particle. Raw material is crushed in jaw or hammer crushers followed by ball mills or vertical roller mills until the desired fineness is met. Usual characteristics demand that a significant proportion of material should be screened via a 200-mesh screen. Hebei Runhuabang New Material Technology Co., Ltd. has advanced crushing and milling machines that make the raw material uniformly fine. We have a complex multi-dimensional management system that checks the size of the particles at various points to guarantee the uniformity of the product batch to batch.
Pelletizing Techniques and Moisture Control
After milling the raw material to the right fineness, the material has to be pressed into green pellets and then fired. Rotary drums or disc pelletizers can be used to pelletize. The secret of quality ceramsite is that it should be manufactured to pellets that are of a uniform size, density, and moisture level. Excessively dry pellets will not swell out well during firing. Excessively wet pellets will either clump or compress. The ideal moisture content is typically 12–18%, depending on the raw material. Hebei Runhuabang New Material Technology Co., Ltd. is a company that offers technical advice to buyers who establish their own ceramsite production lines or to contract manufacturers. Knowledge of the pelletizing process assists the buyer to assess supplier performance and quality of the product.
Firing Temperature and Rotary Kiln Parameters
The strength and lightweight qualities of ceramsite are acquired through firing. The green pellets are introduced in a rotary kiln in which temperatures are as high as 1100 to 1300 degrees Celsius. At such temperatures, the external surface of each pellet fuses in to form a glassy shell as the gases expelled internally form a porous interior. Ceramsite of high strength is sensitive to the kiln temperature, retention time and rotating speed. Excessively low temperature causes weak and underfired particles that are easily crushed. Excessive melting and fusion of particles occur due to too high a temperature. The retention time should be sufficient that allows the equal heat penetration but not excessively long to avoid excessive bloat. Hebei Runhuabang New Material Technology Co., Ltd. applies the most modern production technologies to ensure strict control of these firing parameters so as to have uniform strength and density of ceramsite.
Testing Methods for Compressive Strength and Density
Ceramic buyers cannot be guided by visual inspection in their assessment of the quality of ceramsites. Unified testing procedures are necessary. The compressive strength is usually determined by crushing separate particles or by crushing a bed of aggregate in confinement under a load. Determination of bulk density and particle density is done through displacement methods. The water absorption is a sign of the porosity of the outer shell, which influences freeze-thaw performance. A good ceramsite in structure lightweight concrete must have a density of the particles at 0.8 to 1.2 grams per cubic centimeter and crushing resistance suitable to the application. Hebei Runhuabang New Material Technology Co., Ltd. implements a high level of quality control such as the frequent tests on the strength, density and absorption. Each shipment can be accompanied by certificates of analysis.
Conclusion
To produce high-strength ceramsite, it is necessary to know how to select raw materials, mill, pelletize and fire them. Industrial buyers possessing this knowledge of these steps in the processes are in a better position to assess suppliers and request products that suit their application needs. Hebei Runhuabang New Material Technology Co., Ltd. has both strong technical and economic power and advanced production technologies that help it to provide high quality LECA and ceramsite products. We invite local and foreign traders to negotiate and go together on the path of mutual development. Our team is prepared to assist you, be it in lightweight concrete, geotechnical fill, or filtration, with ceramsite.