In the manufacturing of graphite anode materials for lithium-ion batteries, precision grinding and shaping is a core process to control particle size and optimize morphology. However, over-grinding — the excessive reduction of particle size and destruction of intended particle structure due to prolonged grinding action or mismatched process parameters — is a common production challenge that directly impairs product performance. Over-grinding generates excessive ultra-fine powder, increases specific surface area, raises irreversible lithium consumption during the first cycle, and even breaks already formed near-spherical particles, lowering final sphericity and tap density. As a leading provider of graphite processing equipment with 19 years of engineering excellence, JACAN Powder Equipment has developed a systematic solution to prevent over-grinding based on its four-step core process. Through optimized process design, precise parameter control and intelligent closed-loop management, it achieves stable 10–50μm precision grinding while avoiding the negative effects of excessive processing.
Adopt grinding-classification closed-loop design to discharge qualified particles in time
The root cause of over-grinding is that particles that have reached the target size remain in the grinding chamber and continue to be impacted and sheared by grinding media. To solve this problem fundamentally, JACAN integrates high-efficiency air classification technology into the grinding system to form a closed-loop process of “grinding while grading”.
In this design, graphite materials are ground step by step in the grinding chamber. Once particles are reduced to the target 10–50μm size range, they are lifted by airflow and enter the built-in classification wheel for separation. Particles that meet the size requirement are discharged from the system in time and enter the subsequent spheroidization modification process, while oversized particles fall back to the grinding zone for further processing. This structure fundamentally avoids prolonged retention of fine particles in the grinding area, eliminating the main cause of over-grinding.
Compared with traditional batch grinding that relies on fixed time to control particle size, this continuous closed-loop process not only greatly improves production efficiency, but also ensures that each particle receives moderate grinding action. It effectively reduces the content of sub-micron ultra-fine powder caused by over-grinding, and keeps the particle size distribution of ground products concentrated and uniform.
Optimize grinding and shaping parameters for morphology-oriented processing
Over-grinding in graphite anode production is not only reflected in excessive particle size reduction, but also in the destruction of particle morphology. Excessive grinding will break the smooth edge of near-spherical particles, reduce particle sphericity, and ultimately affect the tap density and electrochemical performance of the product.
JACAN’s grinding and shaping process adopts a morphology-oriented parameter design instead of pursuing excessive size reduction blindly. The process is specially configured for edge optimization, which applies targeted mechanical action to the sharp edges of raw graphite flakes to smooth them into near-spherical morphology, rather than carrying out unrestricted crushing. By precisely adjusting grinding rotor speed, medium filling rate and material residence time, the process achieves accurate control of grinding intensity, which can complete 10–50μm precision grinding and preliminary shaping at one time without causing excessive wear on particle main bodies.
The subsequent independent spheroidization modification process further undertakes the task of improving sphericity to ≥ 0.85 and surface modification. This clear division of labor between grinding and spheroidization avoids the problem of over-grinding caused by trying to complete size reduction and spheroidization all in one grinding step. Each process works within its optimal parameter range, taking into account both processing efficiency and product quality.
Implement standardized raw material pretreatment to stabilize grinding response
The fluctuation of raw material properties is an important inducement of uneven grinding and local over-grinding. If the feedstock has large differences in particle size, hardness and moisture content, the same grinding parameters will cause some soft or fine particles to be over-ground while coarse particles are not fully processed.
JACAN takes raw material pretreatment as the first step of its core process, and strictly controls raw material purity above 99.9% and moisture content ≤ 0.5%. Through uniform pre-crushing, purification and drying treatment, the physical and chemical properties of the feedstock entering the grinding system are highly consistent. With stable material properties, the grinding process shows predictable and uniform response to mechanical action, so operators can set accurate and appropriate grinding parameters according to the feed characteristics, avoiding over-grinding caused by process mismatch due to raw material fluctuation.
In addition, qualified pretreatment eliminates material agglomeration caused by excessive moisture, prevents large agglomerates from causing uneven stress in the grinding chamber, and further reduces the risk of local over-grinding of fine particles wrapped in agglomerates.
Apply intelligent online monitoring for dynamic process adjustment
Traditional manual sampling and off-line detection have obvious hysteresis, and over-grinding often has already occurred when unqualified products are detected. For large-scale continuous production, real-time process monitoring and dynamic adjustment are necessary means to prevent over-grinding.
JACAN’s intelligent grinding system is equipped with online particle size detection and process parameter linkage control modules. The system continuously monitors the particle size distribution of discharged materials in real time, and automatically adjusts key parameters such as feeding speed, classification wheel speed and grinding air volume according to the detection results. When it is detected that the proportion of fine powder exceeds the set threshold, the system will reduce grinding intensity or increase classification efficiency in time to cut off the generation of over-ground particles.
This closed-loop intelligent control greatly reduces the dependence on manual experience, avoids over-grinding caused by human operation errors, and ensures the stability of product particle size distribution among different batches. For 100+ industry leading enterprises that adopt JACAN equipment, this intelligent control system effectively reduces the rejection rate caused by over-grinding and improves overall production yield.
Strengthen post-treatment classification and process feedback optimization
Even with optimized front-end processes, a small amount of over-ground fine powder will still be generated in actual production. Precise post-treatment classification can not only remove these defective particles, but also provide data feedback for front-end process optimization.
In the classification and post-treatment stage of JACAN’s core process, high-precision air classification equipment can accurately cut off ultra-fine particles below the target size range, and cooperate with magnetic separation to ensure ultra-low impurities and batch consistency of finished products. By counting the proportion of fine powder separated by classification, the production team can quantitatively evaluate the over-grinding degree of the front-end grinding process.
If the fine powder rate continues to be high, it means that the grinding parameters need to be optimized, such as reducing grinding time, lowering rotor speed or adjusting classification accuracy. This positive feedback mechanism from post-treatment to front-end grinding can continuously optimize the process scheme in long-term production, gradually reduce the probability of over-grinding, and realize the continuous improvement of production efficiency and product quality.
With 19 years of deep cultivation in the ultra-fine grinding industry, JACAN has accumulated hundreds of technical patents and practical experience in thousands of engineering projects. Its four-step core process for graphite anode processing has been verified by 1,200+ clients worldwide, and occupies a 72% market share in top-tier anode material segments (statistics as of November 2025). In addition to providing high-precision equipment, JACAN also provides on-site installation debugging and professional operator training, helping customers formulate targeted process parameters according to their raw material characteristics and product indicators, so as to fundamentally avoid over-grinding problems in actual production.
In conclusion, preventing over-grinding in graphite production is a systematic work that requires full-process control from raw material pretreatment, grinding process design, intelligent control to post-treatment classification. Instead of simply reducing grinding intensity, JACAN’s solution achieves a balance between high-efficiency processing and precise quality control through process structure optimization, professional division of procedures and intelligent closed-loop management. While ensuring 10–50μm precision grinding and ≥ 0.85 high sphericity, it effectively avoids the performance loss caused by over-grinding, providing reliable technical support for the large-scale production of high-performance graphite anode materials.
