On August 20, Nanhua University announced that Professor Wei Yuezhou's team has successfully separated and obtained high-purity alpha nuclide Lead-212 (Pb-212) and its precursor nuclide Thorium-228 (Th-228) directly from rare earth ore slag. The team achieved the extraction of 158 microcuries of Pb-212/Bismuth-212 from kilogram-level rare earth ore slag in a single batch. This achievement recently passed the technical appraisal for the project "Development of Technology for Extracting Medical Alpha Nuclide Lead-212 and Thorium-228 from Monazite Processing Radium Slag," organized by the China Isotope and Radiation Industry Association. Experts unanimously agreed that the overall technology has reached internationally advanced levels, with the single-pass recovery rate being internationally leading. This breakthrough is expected to promote the independent supply of medical alpha nuclides in China, ensure the safety of the nuclear medicine industry chain, and offer broad application prospects.

With a half-life of 10.6 hours, Lead-212 is one of the most promising targeted alpha therapy nuclides globally, applicable for the precise treatment of various malignant tumors, including breast, pancreatic, and prostate cancers. However, its complex extraction process, low yield, and high cost have hindered the promotion of related targeted drugs. Currently, China relies heavily on imports for medical nuclides and faces long-term supply shortages. There is an urgent need to develop efficient, large-scale production technologies for Lead-212, establish an industry chain for target drug preparation and clinical applications, and accelerate the self-sufficiency of key medical isotopes in China.

Monazite processing radium slag is a waste residue rich in radioactive radium, generated during the production of rare earth products using monazite ore as a raw material. Taking an innovative approach, Professor Wei's team introduced a specific anion into the radium slag dissolution solution, causing Lead-212 to form an "anionic complex." Utilizing a self-developed porous silica-supported anion exchange resin, the team was able to precisely "identify" and "capture" Lead-212 from a solution containing over 20 types of abundant metallic impurities.

Testing revealed that the extracted Lead-212 product achieved a radionuclide purity of up to 99.9%. Barium ion levels were below 1 ppm, and other metallic impurity ions (about 20 types) were all below 0.1 ppm. The single-pass recovery rate for Lead-212 exceeded 90%, while that for Thorium-228 was over 85%. According to Wei Yuezhou, the process meets the conditions for pilot-scale scale-up. This original technology, which "turns harm into benefit and transforms waste into treasure," is also expected to break the global bottleneck of severe shortages in medical alpha nuclide supplies.

It is reported that, applying these research findings, approximately 1 curie of Lead-212 can be extracted from about 10 tons of radium slag, theoretically sufficient to treat 66 cancer patients. After the radium slag solution is left to decay for about 4 days, it can be extracted again, enabling multiple cycles of reuse. In other words, repeatedly processing 50 tons of radium slag annually using this technology could produce 365 curies of Lead-212, enough for approximately 24,000 cancer patients.

In addition to Lead-212, the materials and technologies developed by the team can also directly separate and extract Thorium-228 from radium slag. Thorium-228 has a half-life of 1.9 years and decays into Lead-212. Due to its longer half-life, it is suitable for long-distance transportation and can provide an ample supply of raw materials for domestic and international Pb-212 radiopharmaceutical preparation. Wei Yuezhou stated that this technology is expected to help China achieve large-scale production of Lead-212 in 2 to 3 years, with production capacity gradually expanding to over 1 curie per day.

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