Revitalizing China's salt lakes: Unlocking green industrial potential for sustainable future

Editor's note: The recommendations for the 15th Five-Year Plan have been released, which outline priorities for national economic and social development. CGTN invites industry insiders and experts to interpret the policy implications in science and technology, ecological civilization and ecosystem conservation – key engines of China's high-quality development. Wang Yuanhao, a professor at the University of Science and Technology Beijing, introduces an innovative approach that utilizes resources efficiently, transforming traditional extraction processes into a sustainable, closed-loop system. Wang's article is originally in Chinese and has been translated. The article reflects the author's opinions and not necessarily the views of CGTN.

The 15th Five-Year Plan period (2026-2030) marks a pivotal period in China's journey toward achieving socialist modernization and also a crucial time for transitioning to a green and low-carbon economy. As the nation focuses on strengthening the development of the western regions and accelerating the development of new quality productive forces, how to effectively utilize the vast natural resources in the western regions while ensuring strategic security and promoting green growth has become an urgent challenge for researchers.

Our attention has been increasingly focused on the salt lakes in northwest China's Qinghai Province and Xinjiang Uygur Autonomous Region. These lakes are not only major reserves of strategic resources, but also important testing grounds for China's green circular economy. Ongoing research into the comprehensive utilization of salt lake resources responds directly to the goals outlined in the national plan, particularly those related to improving industrial and supply chain resilience and advancing the clean, low-carbon and efficient use of energy. Through technological innovation, salt lakes can move beyond traditional extraction models and become a foundation for green industrial systems.

Hidden strategic resources

Located across vast desert regions in western China, the salt lakes contain highly concentrated brine formed through long-term evaporation. This brine hosts a complex mix of elements. While lithium has attracted significant attention in recent years due to its role in new energy vehicles, magnesium and chlorine are present in even larger quantities and have broader industrial applications.

Magnesium, often called the "skeleton" of future industries, is vital for lightweighting materials such as those used in high-speed trains, automobiles and wind turbines. Chlorine, on the other hand, is a fundamental raw material for the chemical industry, used in the production of synthetic plastics, rubber and other essential materials.

Despite their importance, these resources have long been underutilized due to the difficulty in extraction.

Traditional methods for extracting magnesium from salt lake brine rely heavily on chemical precipitation, typically through the addition of lime. While technically feasible, this approach has significant drawbacks. It consumes large amounts of chemical reagents, generates vast quantities of magnesium sludge waste, and occupies large areas of land, creating long-term environmental risks. At the same time, residual chloride ions remain in the brine, obstructing the subsequent extraction of other elements like lithium and potassium.

What's more, in conventional routes, magnesium exists as magnesium chloride hexahydrate, in which magnesium ions are tightly bound to water molecules. Removing these water molecules without triggering hydrolysis at high temperatures has been a long-standing technical barrier.

An innovative 'detour' pathway

Facing China's "dual carbon" goal to peak carbon emissions before 2030 and achieve carbon neutrality by 2060, as well as fostering a green circular economy, our researchers have proposed an innovative "detour" strategy. Instead of struggling with the difficulty of dehydration, our team devised a completely new approach: why not prevent magnesium from clinging to water molecules in the first place?

Rather than adding large amounts of chemicals, we introduced a specially designed electrolyzer into the brine. When an electric current is applied, magnesium ions near the cathode are converted to solid magnesium hydroxide, which precipitates out of the solution. This process not only extracts magnesium efficiently, but also generates valuable hydrogen and chlorine gases at the electrodes, both of which are clean energy and essential chemical raw materials.

Then we heated the magnesium hydroxide to remove the remaining water, producing highly active magnesium oxide. This step is crucial as it completely separates magnesium from the hydrated chloride system, effectively bypassing the long-standing dehydration problem.

In a third step, we introduced chlorine gas to the magnesium oxide in a completely dry environment, causing them to react and form anhydrous magnesium chloride.
The final step utilized renewable electricity from western China's abundant solar and wind resources to electrolyze the anhydrous magnesium chloride. The process produced metallic magnesium, while the chlorine gas is recycled for further industrial use, such as the production of Polyvinyl Chloride (PVC).

Green super factory of the future

The story doesn't end here.

Beyond solving the issues with magnesium and chlorine, this innovative process also facilitates integrated resource utilization.

Hydrogen and carbon monoxide generated during the new method are not treated as waste. Instead, they can be used as reducing agents with advanced catalytic technologies to capture carbon emissions from industrial exhaust gases and convert them into organic compounds like ethylene.

This vision reveals the blueprint for a "salt lake green super factory" that integrates multiple industries into a closed-loop system. Inputs include salt lake brine, industrial waste gases, and renewable green electricity from wind and solar power, and outputs include lightweight magnesium alloys, chlorine-based materials crucial for infrastructure construction, and locked-up CO2.

This approach represents more than a single technological breakthrough.

Through this transformation, western China's salt lakes are moving from isolated resource sites to key platforms for green industrial innovation, turning previously underutilized elements into drivers of future growth.

For the nation, it enhances the efficient use of strategic resources and supports long-term carbon reduction goals. For society, it contributes to cleaner production, improved material efficiency and more sustainable and beautiful environment.