Nanshan Alumina Shatters Global Industry Bottleneck

Recently,the China Non-Ferrous Metals Industry Association and other bodies announced the winners of the 2025 China Nonferrous Metals Industry Science and Technology Award.The project"Key Technology and Industrialization for Efficient Removal of Organics from Sodium Aluminate Solution,"submitted by Nanshan Donghai Alumina Co.,Ltd.,was awarded the Second Prize.

Focusing on industry challenges and breaking technical bottlenecks

In the Bayer process for alumina production,there are over 390 types of organic compounds in the sodium aluminate solution.These impurities increase material consumption and environmental risks.The efficient and economical removal of these organics has been listed by the International Aluminium Institute as a long-term priority research direction and remains a critical,common challenge for the global alumina industry.Currently,foreign enterprises mainly employ solution combustion,seawater washing,or lime causticization to remove sodium oxalate.Domestic enterprises have largely focused on sodium oxalate removal as well,with less research dedicated to medium-and high-molecular-weight organics.Overall,the technical bottleneck regarding the efficient and economical removal of organics has not seen a substantial breakthrough for a long time.

Addressing this industry-wide challenge,Nanshan Donghai Alumina targeted the efficient and economical removal of organics from sodium aluminate solution.The company focused on technologies for removing medium-and high-molecular-weight organics and constructed a comprehensive organic removal process combining"front-end removal of medium/high-molecular-weight organics with end-stage intensification of sodium oxalate causticization."In terms of key technical breakthroughs,the project team utilized methods to precisely regulate material properties and constructed a multi-layer interfacial adsorption structure to enhance adsorption capacity,effectively solving the difficulty of removing medium-and high-molecular-weight organics.Simultaneously,by optimizing the sodium oxalate causticization process and suppressing the reverse causticization reaction of calcium oxalate,they significantly boosted causticization efficiency.The synergy of these two technologies achieved efficient,full-process removal of organics ranging from high to low molecular weights.

Team collaboration and innovation

The project was jointly advanced by the R&D team at Nanshan Donghai Alumina and researchers from Central South University.Spanning from October 2020 to December 2021,the R&D team engaged in iterative validation and round-the-clock tackling of difficulties,systematically overcoming technical bottlenecks,including low adsorption efficiency and unstable causticization reactions.Team members rooted themselves in the production line,closely tracking experimental data and continuously optimizing process parameters,achieving breakthroughs in key technologies through persistent exploration.Through concerted effort and perseverance,the team finally overcame challenges,injecting strong momentum into the company's technological innovation and contributing valuable insights to the industry's progress.

Following the industrialization of this technology,the organic carbon content in the sodium aluminate solution at Donghai Alumina dropped significantly,the seed precipitation decomposition rate improved markedly,and the usage of defoamers was drastically reduced.Moreover,the produced aluminum hydroxide and alumina boast superior crystallinity and high whiteness,thereby increasing their added value and market competitiveness.Having successfully substituted imported Australian alumina,these products are now utilized in high-end domestic fine alumina manufacturing.From an industry perspective,the promotion of this technology provides a"Chinese-characteristic"solution for organic removal to China's alumina industry,which has an annual output exceeding 80 million tons.This not only vigorously promotes the green and sustainable development of China's alumina industry but also lays a technical foundation for Chinese alumina enterprises to expand into overseas markets.

Earning authoritative recognition

On August 15,2025,an achievement evaluation organized by the China Non-Ferrous Metals Industry Association stated:"The efficient removal technology for medium-and high-molecular-weight organics reaches a world-leading level."Currently,the project has been granted 4 invention patents with 2 additional patents pending.The team has also led or participated in drafting 6 group,industry,and national standards and published 11 academic papers,achieving significant economic and social benefits.The successful industrialization of this full-system organic removal technology provides an innovative solution for China to address organic issues in imported ores and high-carbon domestic ores,powerfully driving the technological upgrading of alumina production processes.

This award serves as high recognition from the industry for Nanshan Donghai Alumina's technological innovation capabilities and industrialization practices.In recent years,the company has continuously strengthened core technology research and industrial transformation,building a"dual-drive"innovation planning system based on technology and products.Donghai Alumina will further increase R&D investment,relying on technological empowerment to drive progress and industrial upgrading in China's nonferrous metals industry.

[Further Reading]The China Nonferrous Metals Industry Science and Technology Award stands as the only national-level science and technology award specifically for the nonferrous metals industry.Being an integral component of the national science and technology award system,it covers areas such as mining,smelting,processing,new materials,major equipment,energy saving,and recycling,earning high recognition within the industry for its professional standards,rigorous process,and fairness.