China’s refined copper exports surged to a record last month as weak demand in the world’s biggest metals buyer prompted smelters to turn to overseas markets.

Shipments more than doubled to 157,751 tons in June from May, well above the previous all-time high of 102,000 tons in 2012, according to customs data released on Sunday. The figures follow data last week that showed a jump in unwrought copper and copper products exports. 

Asia’s largest economy grew at the slowest pace in five quarters in the three months through June, and the sluggish growth is flowing through to global copper prices, which have dropped by around 14% since mid-May. The People’s Bank of China cut a key short-term policy rate rate for the first time in almost a year on Monday, in a bid to revive activity.

Copper inventories are also swelling due to the lack of Chinese demand. Stockpiles at London Metal Exchange global warehouses have more than doubled since the middle of May, to the highest since September 2021.

“Chinese smelters have been largely sticking to their production plans and opted for exports,” as domestic demand is “very weak”,  said Fan Rui, an analyst at Guoyuan Futures Co. Exports may stay elevated before winding down from September due to a lack of scrap feedstock supply, she said.

In other trade data released over the weekend, Chinese gold imports more than halved in June from the previous month as elevated prices deterred buyers. Aluminum purchases from Russia fell for a third month, and were at the lowest since January 2023.