Treatment of Oily Wastewater from Lithium Battery Precursor Production
I. Background on oily wastewater
In the wave of the global energy transition and the green technology revolution, lithium batteries, as the core power source driving the future, are seeing their production cleanliness and sustainability become an increasing focus for the industry and society. Lithium battery manufacturing, especially in key stages such as electrode preparation, electrolyte filling and equipment cooling, inevitably generates oily wastewater with a complex composition and high treatment difficulty. Such wastewater contains emulsified oil, mineral oil, organic solvents and trace metal impurities. If improperly treated, it poses a severe challenge to the ecological environment and to the sustainable development of enterprises.
Faced with this common industry challenge, we uphold the philosophy of "empowering clean production with technology and protecting green mountains and clear waters" and present an efficient oily wastewater treatment system solution customised for the lithium battery industry, safeguarding your journey towards green manufacturing.
II. Treatment difficulties
Oily wastewater from lithium battery production typically has the following characteristics:
Complex oil states: it contains free oil, dispersed oil and highly stable emulsified oil, which conventional methods struggle to separate completely.
Diverse composition: besides oils and fats, it often carries NMP (N-methylpyrrolidone), binders, conductive agents and trace metal ions such as lithium, cobalt and nickel.
Strict discharge standards: it must meet the stringent requirements for petroleum-based indicators under the Emission Standard of Pollutants for Battery Industry (GB 30484) and local environmental regulations.
Water reuse demand: driven by water conservation, consumption reduction and the circular economy, the treated water must meet the required indicator standards.
III. The SINOKLE treatment process
The process adopted by SINOKLE
Figure 1 Process flow diagram
1. Efficient pre-treatment separation technology
Precise separation: combining cyclone separation and efficient air flotation (such as dissolved-air flotation CDFU) units, efficiently removing the vast majority of free oil and suspended solids and reducing the load on subsequent processes.
2. Advanced purification and membrane technology application
Anti-fouling membrane design: proprietary membrane materials and flow channel design greatly alleviate membrane fouling caused by specific pollutants in lithium battery wastewater, extending cleaning intervals and membrane life and reducing operating costs.
3. Deep oil removal with coalescing filter elements
When oily acidic water flows through a specially designed coalescing filter element, the coalescing medium inside (usually oleophilic and hydrophobic, or specially treated material) forces tiny oil droplets (even some emulsified ones) to collide and merge, gradually coalescing into larger droplets. Owing to the density difference relative to water and the change in surface tension, the enlarged droplets rapidly rise to the top of the vessel under gravity in the subsequent flow or in a dedicated separation chamber, achieving efficient oil-water separation.
4. Resource recovery
Oil recovery: waste oil recovery is effective, with low water content, directly generating revenue; water reuse and value capture: the water produced after advanced treatment is of excellent quality and can be directly reused in non-critical process stages such as cooling and cleaning, greatly reducing fresh water consumption.
5. Intelligent management
Automated operation: the whole system is automatically controlled by PLC or DCS, with fault warning and remote operation and maintenance, ensuring a stable and efficient treatment process and significantly reducing manual intervention and operational risk.
IV. Outstanding value
Stable compliance, no worries: ensures the effluent petroleum-based concentration consistently meets the standard, with indicators such as COD comprehensively better than national and local standards, helping enterprises pass the strictest environmental inspections.
Cost reduction and efficiency gains, enhanced competitiveness: a water reuse rate of up to 70%-90% directly lowers water resource costs and discharge fees. Automated operation and optimised energy consumption design reduce chemical consumption and operation and maintenance expenditure.
Strengthened ESG and brand image: demonstrates the enterprise's determination to fulfil environmental responsibility and practise green manufacturing, enhancing brand reputation and industry leadership and meeting the environmental access requirements of global supply chains.
Compact design, flexible adaptation: the modular design can flexibly adapt to new production lines or the retrofit of existing workshops, with a small footprint and easy capacity expansion.
