Sodium Sulfate Resource Recovery from NMC Precursor-Hangzhou Create Environment & Energy Technology Co

Case Study

Lithium-Ion Battery
Salt Lake Co., Ltd.'s 40,000-Ton Electrodialysis Project The Electrodialysis System at Baqian Lake Zangge Lithium's Boron Removal Electrodialysis System Zijin Mining Group's Bipolar Membrane Project Sodium Sulfate Resource Recovery from NMC Precursor Lithium Hydroxide Production from Lithium Sulfate Lithium Hydroxide Production from Lithium Sulfate
CWW Reuse
Zero Liquid Discharge for Flue Gas Desulfurization Wastewater Zero Liquid Discharge for Metallurgical Wastewater Zero Liquid Discharge for Aluminum Foil Pickling Wastewater Zero Liquid Discharge for Chip Manufacturing Wastewater Separation of Hydrate and Salt from Chemical Fiber Wastewater
Biopharma
Desalination of Betaine Desalination of Human Milk Oligosaccharides Desalination of Calcium Pantothenate Bipolar Membrane Process for Sodium Sarcosinate Bipolar Membrane Process for Tartaric Acid Production Desalination of L-Carnitine Desalination of Glufosinate-Ammonium

Resource Recovery of Sodium Sulfate from NMC Precursor

【Project Overview】

Against the backdrop of rapid global new energy industry development and increasingly stringent environmental requirements, treating sodium sulfate wastewater from NMC precursor production has become a common industry challenge. The sodium sulfate (anhydrous) product from traditional evaporation-crystallization processes is difficult to sell due to market saturation, creating an urgent need for green, resource-recovering, and value-adding technological pathways. This project employs a bipolar membrane electrodialysis system entirely designed, manufactured, and constructed by Create. The sodium sulfate wastewater undergoes multi-stage pretreatment for oil, hardness, and impurity removal. Subsequently, within the bipolar membrane stack under an electric field, water molecules dissociate into H⁺ and OH⁻ ions. These ions combine with sulfate and sodium ions, respectively, regenerating sulfuric acid and sodium hydroxide. The produced 10% acid and alkali streams are concentrated and directly reused in the precursor production line's leaching and precipitation stages. 95% of the water is recovered, establishing a complete closed-loop resource cycle.

【Project Highlights】

Full-Process Precision Engineering Ensures High Efficiency & Stability
The project integrates over ten unit technologies including hollow fiber ultrafiltration, specialty resin adsorption, bipolar membrane electrodialysis, high-pressure reverse osmosis, and alkali-resistant nanofiltration, forming a comprehensive and refined treatment chain. This targeted process effectively removes various impurities like oils and heavy metals, ensuring the final acid and alkali products are of high purity, and providing a solid foundation for the stable and efficient operation of the core conversion step.
A Paradigm of Value Reconstruction, Multiplying Economic Returns
The project successfully achieves disruptive value-upgrading of by-products. Via the core bipolar membrane technology, sodium sulfate (anhydrous), valued at approximately ¥300 per ton, is efficiently converted into sulfuric acid valued at ¥600 and sodium hydroxide valued at ¥3,000 per ton. This increases the total product value by over 6 times, transforming wastewater treatment from a pure "cost center" into a "profit source," and pioneering a new circular economy model of "creating value from waste."
Achieving Near-Zero Liquid Discharge with Significant Environmental Benefits
Through a combined "membrane treatment + evaporator" process, the system achieves near-zero liquid discharge, drastically reducing the total volume of effluent and solid waste requiring off-site disposal. This fundamentally and significantly lowers environmental risks and compliance costs, achieving a deep integration of environmental and economic benefits.
Leading Industry Transformation: From "Pollution Control" to "Value Creation"
The successful implementation of this project transcends traditional end-of-pipe treatment. It powerfully promotes a strategic shift for the industrial wastewater treatment sector from being a "cost center" to a "value center." It provides a replicable green development path of "resource regeneration - value enhancement" for the entire new energy materials industry, holding significant significance for the sector.