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Driven by the new energy and semiconductor industries, the market demand for 4N/5N high-purity alumina continues to rise. When sourcing suppliers, many procurement professionals ask: What are the main production processes for 4N/5N high-purity alumina? What are the differences between products made by different processes? Which domestic manufacturers are reliable? This article provides a comprehensive overview from the perspective of production processes.
Currently, there are three mainstream production processes for 4N/5N high-purity alumina:
First, the modified Bayer process, which purifies industrial alumina through alkaline dissolution, impurity removal, and decomposition steps, offering lower costs and suitability for large-scale production of 4N-grade products;Second, the alkoxide hydrolysis method (organic method), where high-purity aluminum reacts with alcohol to produce aluminum alkoxide, which is then hydrolyzed and calcined to obtain high-purity alumina with purity reaching over 5N and precise impurity control, though at a higher cost;Third, the ammonium aluminum sulfate thermal decomposition method, which purifies via recrystallization followed by high-temperature decomposition, yielding high purity but with particle sizes that are relatively difficult to control.
Shandong Greatsun Aopeng utilizes an advanced composite purification process that combines the advantages of multiple techniques. Typical specifications for 4N high-purity alumina are:
Al2O3 ≥ 99.99%, Na ≤ 15 ppm, Si ≤ 8 ppm, Fe ≤ 3 ppm, Ca ≤ 5 ppm, tunable particle size D50 = 1–5 μm, surface area 6–15 m2/g, and bulk density 0.3–0.6 g/cm3.For 5N products, Al2O3 ≥ 99.999%, total impurity content ≤ 10 ppm, and particle size D50 = 0.5–3 μm, meeting high-end demands such as sapphire single crystal growth.
What Are the Application Differences Between Processes, and How Should You Select?
The production process determines product characteristics.Modified Bayer process products have coarser particle sizes and lower costs, making them suitable for cost-sensitive fields such as lithium battery separator coatings and standard ceramics;Alkoxide hydrolysis process products feature high purity, fine particle sizes, and large surface areas, making them suitable for high-end applications such as LED phosphors, catalyst supports, and precision ceramics;Ammonium aluminum sulfate process products offer high purity but suffer from severe agglomeration, requiring subsequent deagglomeration and dispersion processing.
Selection recommendations:Choose 4N Bayer-process products for lithium battery separator coatings due to high cost-performance and optimal particle size matching for coating processes;
Choose 4N or 5N alkoxide-process products for LED phosphors for low impurity levels and high luminous efficiency;Must select 5N alkoxide-process products for sapphire substrates, as insufficient purity leads to crystal cracking and reduced optical transmittance.Shandong Greatsun Aopeng can recommend suitable products based on customer application scenarios and provides customized particle size services.
Practical Application Performance of 4N/5N High-Purity Alumina in the Lithium Battery Industry.
A leading domestic lithium battery separator manufacturer adopted Shandong Greatsun Aopeng 4N high-purity alumina as a ceramic coating raw material for separator production, with a coating weight of 3–5 g/m2.After application, separator thermal shrinkage dropped from 5% to 1.5% (150°C/1h), puncture strength increased by 25%, and batteries passed a 130°C hot-box test with zero smoke and zero fire, significantly enhancing safety performance.Meanwhile, the product's concentrated particle size distribution resulted in zero pump clogging and zero streaking during coating, achieving a coating uniformity pass rate of 99.2%. It has passed supplier certification for multiple power battery enterprises.
Key Competitive Advantages of Shandong Greatsun Aopeng 4N/5N High-Purity Alumina
The core advantages of Shandong Greatsun Aopeng high-purity alumina include:
First, flexible processing, offering both Bayer-process and alkoxide-process products to meet diverse customer needs;Second, stable purity, with lot-to-lot main content fluctuation ≤ 0.005% and precise impurity control;Third, controllable particle size, with D50 customizable within 0.5–15 μm, featuring a narrow distribution without coarse oversized particles;Fourth, sufficient capacity, with strong monthly production capability to ensure stable supply to large-scale accounts;Fifth, professional service, providing comprehensive technical support from product selection to process optimization.For detailed technical solutions and sample testing of 4N/5N high-purity alumina, please contact Shandong Greatsun Aopeng.
