Chemist's contributions worth their weight in gold

By Peng Kuang (China Daily)
Updated: 2009-01-10 07:44

Three decades ago, China had to exchange 5 tons of gold for 1 ton of rare-earth metals, essential elements it needed for the materials industry.

Chinese Premier Wen Jiabao (R) shakes hands with chemist Xu Guangxian (L), winner of China's 2008 State Top Scientific and Technological Awards, during the awarding ceremony at the Great Hall of the People, in Beijing, January 9, 2009. [Xinhua]

That was until Xu Guangxian, a professor at Peking University and member of the Chinese Academy of Sciences (CAS), came up with a novel way to extract and process the metals.

His idea helped slice their cost of production to less than the price of pork.

"Rare earth" is the name given to a group of elements in the periodic table. They are widely used in manufacturing modern technological devices, such as TVs, hybrid cars, high-volume batteries and armor for tanks and missiles. Studies on possible other uses for rare earth are still ongoing.

Processing the material for use is a costly affair because of its special chemical properties.

In the 1970s, Xu began researching technology for the separation of rare earth metals. Before that, he made important discoveries and contributed to China's materials industry.

Xu graduated with a PhD from Columbia University in quantum chemistry, giving him a strong background in theoretical calculations.

Before embarking on his research of rare earth metals, he worked for 20 years in the department of technical physics at Peking University. His work covered experimental research on the separation of Uranium-235 and Uranium-238, key fuel materials for nuclear technology.

Xu was appointed to lead the research in this field because of his expertise, proven accomplishments and continual study of the need for rare earth metals in the country.

"I conduct the experiments in the daytime and continue thinking about the subject into night," Xu said in an interview with China Central Television.

Xu invented a process known as "countercurrent extraction" that reduced the time taken to process the material from years down to weeks.

The impact of his contribution was immediate. The price of pure rare earth metals plunged from five times that of gold in the 1970s to just 20 yuan per kilogram for one of them, samarium, last year.

Xu is "the father of Chinese rare earth chemistry", the Xinhua News Agency said.

Xu was born in Shaoxing, Zhejiang province, in 1920. He studied at Shanghai Jiaotong University and earned a bachelor of science degree in 1944.

In 1948, he went to the United States to study at Washington University in St Louis, before enrolling at Columbia University in New York, from where he received his doctorate in 1951.

In May of that year, Xu returned to China with his wife Gao Xiaoxia, another famous chemist. Months later, he was appointed professor of the department of chemistry at Peking University and became its dean in 1956.

His works in the early 1950s built the foundation for China's chemistry education. Over the years, Xu has trained thousands of chemists, three of whom are also members of the CAS.

"As a theoretical chemist, he has great experimental skills, and among experimental chemists, he is excellent on theory," Wang Bingwu, Xu's final PhD student, said of his mentor.