What Is the Most Suitable Membrane for Brine Refining?

At the conference, Cai Yubing, Deputy Manager of the Chemical Division at Jiuwu Hi-Tech, delivered a keynote speech titled "Application of Jiuwu Membrane in the Field of Brine Refining," providing an in-depth explanation of how ceramic membrane technology addresses industry pain points and helps enterprises achieve energy savings, consumption reduction, and stable production.

Cross-flow and Dead-end: Precisely Matching Raw Material Characteristics

In the brine refining process, differences in raw water quality — particularly variations in calcium and magnesium ion content — place extremely high demands on process selection. Leveraging its deep technical expertise, Jiuwu Hi-Tech offers flexible and efficient solutions.

Cross-flow Filtration Process: For high-magnesium material systems, Jiuwu Hi-Tech primarily promotes tubular ceramic membrane cross-flow filtration technology. This technology, through the flow of fluid parallel to the membrane surface, continuously scours the membrane surface, effectively reducing particle deposition and membrane fouling. This characteristic gives it significant advantages in treating high-concentration suspended solids or viscous liquids, enabling long-term flux stability and continuous automated operation, while greatly reducing maintenance frequency.

Dead-end Filtration Process: For raw salt, brine, and well rock salt with low magnesium and high calcium content, the dead-end filtration mode is recommended. This vertical permeation filtration method achieves optimal performance under specific water quality conditions.

Core Technical Advantages – Forging Excellence

Jiuwu Hi-Tech's tubular ceramic membrane brine refining technology is reshaping industry standards with its unique advantages.

High Efficiency and Stability: This process features a short process flow, minimal equipment, simple operation, and a small footprint. Its core lies in high-precision filtration capability, with membrane pore sizes smaller than the particle size of magnesium hydroxide, enabling complete retention of magnesium hydroxide and ensuring stable effluent quality. In the treated brine, the calcium and magnesium ion content can be controlled to ≤ 1 ppm, and suspended solids (SS) content to ≤ 0.5 ppm, greatly improving the quality of refined brine, effectively reducing the scaling cycle of downstream evaporators, and thereby increasing the production capacity of crystallized salt.

Economy and Durability: The technology features strong anti-fouling capability, maintaining stable operation even at pollutant concentrations as high as 2% v/v. A longer acid cleaning cycle (up to 30 days, far exceeding the 3 days or less of traditional processes) means lower consumption of acid, alkali, and cleaning water, as well as smoother production control. In addition, the inorganic ceramic membrane itself possesses exceptional chemical stability, unaffected by acids, alkalis, or oxidants, with a service life exceeding 10 years. Combined with a filter body made primarily of titanium material, the overall equipment service life can exceed 20 years, delivering long-term value to users.

Membrane Desulfation and Concentration Reuse – Building a Circular Economy

In addition to its core brine refining technology, Jiuwu Hi-Tech also demonstrates strong technical capabilities in membrane desulfation and brine reuse.

Membrane Desulfation Process: This mature and reliable process has been successfully applied in multiple countries, including Egypt, Indonesia, India, Vietnam, Russia, and Kazakhstan. Its features include stable automated control in the pretreatment stage, and an innovative single-pump design in the membrane separation stage for smoother control. Combined with a low-temperature crystallization process, the resulting salt slurry crystals are large in size and easy to settle. Through a combined process of ordinary nanofiltration and high-pressure nanofiltration, not only is equipment reduced and the process flow shortened, but the sodium chloride recovery rate is also improved, making the salt separation step more energy-efficient and economical.

Membrane Concentration and Brine Reuse Process: This process cleverly utilizes the stable residual pressure from the ceramic membrane concentrate discharge, eliminating the need for an additional concentrate feed pump, thereby saving on equipment procurement, electricity consumption, and maintenance costs. The entire process can be fully automated, with a concentrate recovery rate exceeding 60%, truly turning waste into treasure and helping enterprises build a green circular economy system.

This annual conference of the chlor-alkali industry was not only a recognition of Jiuwu Hi-Tech's position as a technology leader in the sector, but also marked a consensus that membrane technology plays a critical role in driving the green, efficient, and intelligent transformation of the salt chemical industry. Going forward, Jiuwu Hi-Tech will continue to deepen its expertise in membrane separation technology, working hand in hand with industry peers to deliver more advanced, more economical, and more sustainable solutions, jointly writing a new chapter in the high-quality development of China's salt chemical industry.