Eliminating SS, Barium and Organic Impurities from Chlor-Alkali Brine Using Ceramic Membrane Technology

In the roaring workshop of Caustic Soda Plant No. 2 of Tangshan Sanyou Chlor-Alkali Co., Ltd. (hereinafter referred to as "Sanyou Chlor-Alkali"), a technological iteration in crude salt refining is quietly changing the production logic of traditional chemical industry. As the birthplace of "Sanyou Brand" sodium hydroxide, a famous product of Hebei Province, this plant produces up to 530,000 tons of caustic soda annually. And behind this huge production capacity lies a set of ceramic membrane filtration systems that have withstood market tests for fourteen years and continuously reinvented themselves. From the first cooperation in 2012 to winning the bid again in 2024, Jiuwu Hi-Tech and Sanyou Chlor-Alkali's journey is not just a simple equipment procurement, but a deep dialogue about quality commitment and technological leadership.

Turning the clock back to 2012, at that time, Sanyou Chlor-Alkali was facing the pain points of the primary brine refining process. Although the original organic membrane equipment solved some problems, it had a large investment budget, occupied a large area, and was extremely sensitive to changes in crude salt, resulting in a short regeneration and cleaning cycle and great difficulty in operation and maintenance, severely restricting the improvement of production efficiency. After inspecting the operating conditions of many domestic chlor-alkali plants, Sanyou Chlor-Alkali turned its attention to Jiuwu Hi-Tech.

In December 2012, the two parties officially signed the contract for the "120,000 tons/year ionic membrane caustic soda" project, and Jiuwu Hi-Tech provided two sets of 125 m² ceramic membrane equipment. As a leading enterprise in the domestic ceramic membrane field, Jiuwu Hi-Tech had deeply cultivated membrane material R&D and application for nearly three decades, building a full industry chain layout covering "raw materials – membrane elements – equipment systems – engineering services." Addressing the pain points of primary brine refining in the chlor-alkali industry, Jiuwu Hi-Tech customized a complete solution with a ceramic membrane inorganic membrane filter, simplifying the operation process and stabilizing operations. The primary brine refining achieved operational automation, meeting the index requirements of Ca²⁺ + Mg²⁺ ≤ 1 mg/L and SS ≤ 1 mg/L for the primary refined brine, precisely matching the enterprise's production needs.

This cooperation became a "touchstone" for testing product quality, and the on-site operational data provided the most powerful answer. In actual production, after five years of stable operation, the equipment only required replacement of accessories such as membrane tubes. This ultra-long service life and extremely low maintenance frequency laid the groundwork for the subsequent deep cooperation lasting more than ten years.

Technical Advantages of Jiuwu Hi-Tech Ceramic Membranes in the Chlor-Alkali Industry

• Broad Adaptability, Stable and Reliable: The cross-flow filtration mode breaks through the limitations of traditional dead-end filtration. It is compatible with sea salt, lake salt, refined salt, brine, and salt types with inverted calcium-magnesium ratios. It has strong ability to cope with fluctuations in raw salt quality, ensuring continuous and stable production.

• Excellent Precision, Protecting the Core: The ceramic membrane filtration precision reaches 50 nm. The SS content of refined brine is stably controlled below 0.5 ppm, thoroughly removing fine impurities. This ensures the long-term stable operation of the ionic membrane, significantly extends the service life of the ionic membrane, and reduces the replacement cost of core equipment.

• Long Service Life, Cost Reduction and Efficiency Improvement: The ceramic membrane is made of inorganic materials such as alumina and zirconia, offering high mechanical strength, resistance to acid and alkali corrosion, and resistance to high temperature and high pressure. Its service life in the chlor-alkali industry exceeds five years. The filter body is designed with full titanium material, resistant to corrosive environments, completely solving the problems of traditional rubber-lined/plastic-lined equipment which are prone to corrosion, have short service lives, and require frequent shutdowns.

• Compact and Integrated, Intelligent and Controllable: The process flow is short, requiring no complex pretreatment system. The equipment footprint is greatly reduced, optimizing workshop layout. The system is highly automated, supporting one-key start/stop, unattended operation, and fully automatic acid cleaning, reducing manual operations and labor intensity, improving intrinsic safety, and helping enterprises achieve 6S standardized management.

• Green and Low-Carbon, Cyclic and Efficient: The fully enclosed operation system prevents salt mist volatilization and pollution, improving the production environment. The salt mud filtrate is reused, greatly increasing water resource utilization and reducing solid waste emissions. This aligns with the green chemical development concept and helps enterprises fulfill their "dual carbon" responsibilities.

Thanks to the outstanding performance of the initial project, the cooperation between the two parties entered the fast lane. In June 2015 and June 2022, relying on its solid technical strength, Jiuwu Hi-Tech won bids and signed contracts for the "120,000 tons/year ionic membrane caustic soda" project on two more occasions. Each collaboration served as another verification and upgrade of product performance.

In December 2024, in the fiercely competitive bidding for the "High-efficiency One-step Crude Salt Refining Technological Transformation" project at Caustic Soda Plant No. 2 of Sanyou Chlor-Alkali, Jiuwu Hi-Tech stood out with its profound technical expertise and excellent reputation for cooperation, successfully securing the order for two sets of 250 m² ceramic membrane equipment. This time, it was not just about hardware delivery, but a comprehensive output of intelligent solutions.

With the fully automated acid cleaning process, the newly commissioned system has achieved a high degree of automation in the regeneration operation steps that take place every two weeks. This improvement directly addresses the pain points of frontline production, not only significantly reducing labor intensity but also effectively avoiding the risk of manual errors. Supported by the DCS (Distributed Control System), the removal of impurities from crude brine refining has become more precise, and batch stability has been significantly improved, truly realizing the leap from "manufacturing" to "intelligent manufacturing."

From 2012 to 2026, fourteen years have witnessed the rise of domestic ceramic membrane technology in the chlor-alkali industry. For Sanyou Chlor-Alkali, choosing Jiuwu Hi-Tech means choosing a high-quality partner offering a short process flow, simple operation, long service life, and low investment estimates. To date, Jiuwu Hi-Tech has promoted and applied its technology in over 100 enterprises, including Sinopec, Wudi Xinyue Chemical, Henan Lianchuang Chemical, Shandong Haobang Chemical, CNCIC Changzhou Chemical, Tangshan Sanyou, and Shandong Haihua, among others, signing contracts totaling 24 million tons/year of ionic membrane caustic soda. This has promoted the development of China's chlor-alkali industry toward high efficiency, high quality, green energy saving, and consumption reduction, and has been hailed as a "revolution" in the chlor-alkali industry.