Sichuan Yibin Lithium Iron Phosphate Nitrogen Closed Conveying Case

In the rapidly evolving landscape of lithium battery material processing, the transport of fine powders such as lithium iron phosphate (LFP) presents specific engineering challenges. This case study examines a nitrogen-closed conveying system implemented at a production facility in Yibin, Sichuan, designed to address material handling requirements for LFP cathode active materials. The system was developed following a thorough analysis of site conditions, material characteristics, and operational safety standards.

Customer Challenges

The customer, a producer of lithium iron phosphate cathode materials, encountered several critical issues in their existing powder transfer process. Primary concerns included uncontrolled dust emissions during manual handling, which led to material loss and compromised workplace air quality. The hygroscopic nature of LFP powder also risked moisture absorption, degrading product quality. Additionally, the highly combustible dust raised safety hazards, as traditional open conveying methods could not effectively manage oxygen concentration within the system. Frequent line blockages caused by powder agglomeration further reduced throughput and increased maintenance downtime. The facility required a solution that could maintain an inert nitrogen atmosphere throughout the conveying path while ensuring consistent flow and minimal product contamination.

Solution Overview

The delivered system employs nitrogen-closed dense-phase pneumatic conveying, engineered to address each identified pain point. The entire conveying line is sealed and purged with high-purity nitrogen, effectively displacing oxygen to suppress dust explosion risks. Positive pressure nitrogen injection ensures stable material movement while preventing ambient moisture ingress. A centralized control unit monitors pressure, flow rate, and oxygen levels in real time, automatically adjusting nitrogen supply to maintain the desired inert environment. The conveying path uses smooth-bore pipework with optimized bends to reduce wear and avoid powder accumulation. At the receiving end, a cyclone separator and dedicated bag filter recover the conveyed material, returning any residual dust to the process. This configuration eliminates manual intervention, reduces fugitive emissions, and supports continuous operation with predictable performance.

System Benefits

By implementing this nitrogen-closed conveying approach, the customer achieved several measurable improvements. Dust emissions were reduced to near-zero levels, improving workplace safety and regulatory compliance. Product moisture content remained stable, preserving the electrochemical properties of the LFP powder. The inert atmosphere significantly lowered the risk of combustible dust incidents, satisfying strict safety requirements for lithium battery material processing. Throughput increased by 25% compared to the previous method, while maintenance intervals extended due to reduced abrasive wear and fewer blockages. The system's automated controls also reduced operator workload and allowed seamless integration with upstream and downstream equipment.