A Chinese court imposed jail sentences and fines on Tuesday on 27 people for shipping antimony ingots out of the country without export licences, in a ruling that highlights how China is tightening enforcement of its controls on strategic minerals.

China is the world's largest producer of antimony, which is used in batteries, chips, flame retardants and the defence sector. Beijing added antinomy to its export control list, opens new tab in September 2024.

Last month, China said it had suspended a ban on exports of antimony, gallium and germanium to the United States following a meeting between Presidents Xi Jinping and Donald Trump, but the metals remain subject to broader export controls requiring shippers to first obtain licences from Beijing.

The main defendant, Wang Wubin, was sentenced to 12 years in prison and fined 1 million yuan ($141,899) for smuggling the antimony ingots, the Shenzhen Intermediate People's Court said in a statement on its WeChat account.

Wang was found to have conspired with smugglers overseas to organise other defendants to buy antimony ingots and smuggle them out of the country through concealment, disguise and false declaration without the required export licences in February and March this year, according to the statement.

The penalties for the other 26 defendants include fines and prison sentences ranging from four months to five years, depending on the volumes of the smuggled metal.

The case involved the smuggling of more than 166 metric tons of antimony, of which Chinese customs seized more than 96 tons, the court statement said.

In April, Hong Kong authorities said they had seized a cargo of antimony ingots. No arrests were announced at the time.

Reuters exclusively reported in July that unusually large quantities of antimony had poured into the United States from Thailand and Mexico after China barred U.S. shipments last year.