China restricts exports of high-tech metals ahead of Yellen's visit
The HinduChina has imposed export curbs on two metals used in computer chips and solar cells, expanding a squabble with Washington over high-tech trade ahead of U.S. Treasury Secretary Janet Yellen's visit to Beijing. China is the biggest global source of gallium and germanium, which are produced in small amounts but are needed to make computer chips for mobile phones, cars and other products, as well as solar panels and military technology. The United States has blocked Chinese access to advanced chips and the technology to manufacture them and has persuaded allies the Netherlands and Japan to limit exports of chipmaking tools. That threatens to delay or derail the ruling Communist Party's ambitions to make China more prosperous and increase its global influence by becoming a leader in clean energy, telecoms, artificial intelligence and other technologies.