Innovators break foreign monopoly on copper

"There are no shortcuts in scientific research. You have to build from the basics, step by step."

For Wang Yanfeng, general manager of Jinchuan Group Precision Copper Co, those sentiments are more than just words, they are a guiding principle she has followed for over three decades.

That principle was put to the test in 2021, when overseas supplies of high-purity oxygen-free copper, a critical material used in heavy-ion accelerators for cancer treatment, were disrupted.

The timing couldn't have been more inconvenient. Heavy-ion accelerator technology had already been established as Gansu province's signature high-end manufacturing industry. At the time, Lanzhou Ion Therapy Co, one of China's leading developers of the technology, was ramping up production to meet growing domestic and international demand. And without a stable supply of the copper, deliveries of the equipment could have been delayed.

Wang and her team were tasked with developing the material themselves.

"We honestly had no confidence at the beginning," Wang said. "There was no domestic experience to learn from, and foreign technology was completely blocked."

Rather than waiting for specialized vacuum equipment or outside assistance, Wang's team chose a different path. They improved the process from raw materials to production, tightening impurity control at every stage while upgrading existing production lines with new protective technologies.

They simultaneously tested multiple technical routes and refined each step based on performance results. Some experiments went on late into the night, only for the next round of tests to begin the following morning.

After more than a dozen rounds of trials, a breakthrough was achieved.

The approach enabled Jinchuan to produce 4N5 high-purity oxygen-free copper without relying on costly vacuum manufacturing, a breakthrough that significantly shortened development time and reduced production costs by about 30 percent.

By 2024, the company's 4N5 oxygen-free copper had fully matched the performance of imported products.