Pursuing Ultrafine & High-Purity Materials | Nano Grinding & Spray Drying Production Line for Spherical Alumina Separator Thermal Conductive Materials Boosts Lithium Battery Safety

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Pursuing Ultrafine & High-Purity Materials | Nano Grinding & Spray Drying Production Line for Spherical Alumina Separator Thermal Conductive Materials Boosts Lithium Battery Safety

2026-07-03

Explosive Market Demand: Spherical Alumina Acts as Core Guarantee for Separator Thermal Conductive Materials

Amid the explosive growth of the new energy vehicle market, its whole industrial chain has entered a rapid development phase. Battery thermal management systems, the core link directly related to personal safety, are seeing exponentially rising demand for high-performance thermal conductive materials. Boasting high thermal conductivity (30–42 W/(m·K)), outstanding flowability, high filling ratio and excellent insulation & flame retardancy, spherical alumina has become the primary filler for thermal interface materials.

More crucially, in the lithium battery industry, refined alumina (including spherical alumina, boehmite, etc.) serves as an irreplaceable safety barrier as the key functional coating material for battery separators. The mainstream lithium battery separators are mainly made of polyethylene (PE) and polypropylene (PP), which feature low melting points (130–165°C) and poor thermal stability. Under high temperature or local overheating, they tend to thermally shrink or even rupture, easily triggering internal short circuits, fire hazards and explosions. Coating a layer of ultrafine high-purity alumina ceramic on one or both sides of separators can raise their heat resistance to over 500°C, effectively restrain thermal shrinkage, enhance mechanical strength and electrolyte wettability, thus drastically improving battery safety and cycle life.

As the world’s largest manufacturer of new energy vehicles and power batteries, China faces continuously surging demand for high-purity, ultrafine and spherical alumina powder, with unprecedented stringent standards on particle size distribution, purity, sphericity, dispersibility and other indicators.

High-Purity Alumina Ceramic Powder: Precision Control Chain from Raw Materials to Finished Products

The preparation of high-purity alumina ceramics constitutes a precision manufacturing chain integrating chemical purification, physical forming and high-temperature sintering, whose core lies in the ultra-fining, high-purification and spheroidization of raw powder. In traditional processes, industrial alumina has to go through multiple procedures including Bayer process purification, wet ball milling, washing & impurity removal, calcination for crystal phase transformation (α-Al₂O₃) and spray granulation to produce powder suitable for high-end ceramics or battery separator coating.

Nevertheless, conventional grinding equipment struggles to prepare nano-scale alumina slurry with D50 ≤ 1μm, narrow particle distribution, zero agglomeration and ultra-low metallic impurities. Meanwhile, traditional spray drying towers suffer from uneven atomization, turbulent hot air, low powder recovery rate and high hollow particle ratio, which severely undermine the flowability and sintering density of final powder. Therefore, the integrated production line combining nano grinding and intelligent spray drying is the key to breaking bottlenecks in manufacturing high-end alumina powder.

Longxin Intelligent: Integrated Line of High-Flow Pin-Type Nano Bead Mill & High-Temperature Spray Drying Tower for Ultrafine High-Purity Spherical Alumina Production

To address the urgent demand for high-safety battery materials in the new energy industry, Longxin Intelligent has innovatively launched an integrated production line consisting of high-flow pin-type nano bead mills and high-temperature intelligent spray drying towers. Custom-tailored for high-end powders such as spherical alumina, boehmite, activated alumina, nano alumina and high-purity granulated alumina, this line comprehensively elevates the quality of separator thermal conductive materials.

Centered on four core links: ultrafine grinding, precise separation, efficient granulation and intelligent control, the line forms a full closed-loop workflow from raw slurry to high-flow spherical powder, ensuring finished products comply with strict standards for power battery separator coating: high purity, narrow particle size distribution, high sphericity and low metallic impurity content.

How Longxin WSP Series High-Flow Pin-Type Nano Bead Mills Achieve Superior, Stable & Cost-Efficient Grinding

Longxin Intelligent WSP series high-flow pin-type nano bead mills redefine the limits of nano grinding via three core technological innovations:

Composite Turbine-Pin 3D Grinding System
Inside the silicon carbide grinding chamber, materials are subjected to dual forces of circumferential vortex flow and radial impact. Matched with 0.2–0.5 mm high-roundness zirconia beads, particles are refined through combined shear, collision and extrusion, enabling stable control of D50 between 100 nm and 2 μm.
Screenless Centrifugal Separation Technology
Fully eliminating traditional metal screens, it separates grinding media and slurry via centrifugal force fields to completely avoid screen clogging and metallic contamination. It supports ultra-long continuous operation and meets cleanliness requirements for high-purity material production.
Intelligent Closed-Loop Control System
Integrated with PLC, temperature/pressure sensors and online particle size detectors, the system can link with MES systems to realize automatic parameter adjustment, full quality traceability and flexible product changeover, compatible with multiple material systems including lithium iron phosphate, silicon-carbon anodes and boehmite.
The silicon carbide grinding chamber delivers 3 times higher thermal conductivity than stainless steel. Paired with jacket wall cooling, it maintains low discharge temperature, effectively preventing phase transformation or agglomeration of heat-sensitive materials like boehmite and stabilizing slurry performance.

High-Temperature Spray Drying Tower: CFD Simulation & Fully Self-Developed Technology for High-Sphericity Granulated Powder

Customized for high-quality slurry after nano grinding, Longxin Intelligent’s high-temperature intelligent spray drying tower features five technical highlights to guarantee flowability, sphericity and recovery rate of granulated powder:

CFD-Optimized Hot Air Distribution System
Numerical simulation precisely regulates the internal hot air flow field to realize uniform drying, eliminating local overheating or incomplete drying.
Fully Self-Developed Ultra-High-Speed Centrifugal Atomizer
Rotational speed reaches up to 20,000 rpm, generating finer atomized droplets with narrower size distribution and boosting pellet spheroidization rate.
Customizable Atomizer Disks for Multiple Scenarios
Flat disks, toothed disks and composite disks are available to adapt to alumina, boehmite and other slurries with varying viscosity and solid content.
Dual Oil-Air Cooling System with Real-Time Monitoring
Enables long-term stable operation of the atomizer under working temperatures above 200°C.
Advanced Offline Pulse Bag Dust Collector
CFD-optimized flow field structure fitted with heat-resistant filter bags (temperature resistance ≥200°C) and cold air protection system achieves powder recovery rate over 99%, minimizing loss of ultrafine powder.

Alumina powder granulated by this system boasts high sphericity and excellent flowability, which can be directly fed into automatic coating lines and greatly improve the uniformity and adhesion of separator coating layers.

Integration of Multi-Dimensional Energy-Saving Technologies: Longxin Intelligent Develops High-Efficiency Low-Consumption Spray Drying Systems

As high-energy-consuming equipment, spray drying towers usually see energy costs account for over 50% of total operating expenses. Through systematic multi-dimensional energy-saving strategies in equipment design and practical application, Longxin Intelligent effectively cuts energy consumption, lifts thermal efficiency and unifies high-efficiency drying with green manufacturing. Core energy-saving technical routes are listed below:

Hot Air Energy Management to Improve Heat Utilization Efficiency
- Optimized temperature difference between air inlet and outlet: Raise inlet air temperature on the premise of qualified powder moisture content to reduce required hot air volume.
- Waste heat recovery system: High-temperature exhaust gas carries 10–20% of process heat. Longxin Intelligent standardly equips air-air heat exchangers or exhaust recirculation preheating modules. Recovered waste heat can preheat fresh intake air to lower the load of main heaters, and preheat feed slurry to 40–60°C to reduce viscosity and optimize atomization effect.
Precise Regulation of Process Parameters to Cut Energy Consumption at the Source
- Elevate feed solid content: Raising the solid loading of alumina slurry from 30% to 45–50% reduces water evaporation volume by nearly 30%, directly slashing energy consumption by over 20%. High-solid low-viscosity slurry produced by Longxin nano bead mills provides reliable support for high-concentration feeding.
- Intelligent atomization matching: Variable-frequency centrifugal atomizers dynamically adjust rotational speed according to slurry properties to ensure uniform droplet size, avoiding secondary drying or fine powder loss caused by oversized droplets. Even atomization shortens drying duration and eliminates invalid heat loss.
Stable Continuous Feeding
High-precision screw pumps with PID flow closed-loop control eliminate temperature fluctuations induced by unstable feeding, stabilize the thermal field inside the tower and avoid repeated reheating cycles.
Optimized Equipment Structure & System Design
High-efficiency dust collection and powder recovery: Heat-resistant bag dust collectors with offline ash cleaning achieve recovery rate above 99%. Reduced material loss equals lower energy consumption per unit product. Automatic periodic ash cleaning stabilizes system pressure drop and cuts power consumption of induced draft fans.
Intelligent Control System for Dynamic Energy Conservation
- 3D thermal field monitoring: Multi-point sensors installed at air inlet, drying zone and air outlet build real-time thermal distribution models.
- Adaptive algorithm parameter tuning: Automatically adjust inlet air temperature, atomizer rotational speed and exhaust air volume based on feed concentration and ambient temperature & humidity to keep equipment running at the minimum valid energy consumption point.
- Recipe storage & one-click switching: Pre-save optimal drying curves for spherical alumina, boehmite, activated alumina and other materials to eliminate energy waste from trial-and-error process adjustment.

Intelligent Production Lines Safeguard Battery Performance: From Controllable Material Properties to Reliable System Operation

Longxin Intelligent’s integrated nano grinding & spray drying line not only solves manufacturing challenges of spherical alumina powder (ultrafine particle size, high purity and high sphericity), but also realizes batch consistency, full traceability and flexible production via full-process intelligent control. This solution has been successfully deployed in many leading battery material manufacturers to produce functional coatings such as spherical alumina and boehmite composite layers for power battery separators.

In an era prioritizing new energy safety, every micron of material precision matters to the travel safety of thousands of end users. Longxin Intelligent will keep deepening R&D of nano grinding and intelligent drying technologies, adhering to the mission of matching equipment performance with industrial demands. We deliver stable, efficient and intelligent full-process solutions for customers producing high-end powders including spherical alumina, high-purity alumina ceramic powder and boehmite, empowering the new energy industrial chain to step into a new era of higher safety and superior performance.