Customs inspectors at Fangchenggang, in Guangxi province in southern China, said the cargo was reported by a Shanghai-based company as copper concentrates - a feedstock used by copper smelters for making refined copper.
However, a photo issued with an official statement on October 11, shows customs officials inspecting a big pile of black powder at Fangchenggang.
The black powder was found to be a mixture of copper concentrates and residual slag from solvent extraction electrowinning (SX-EW) processing of copper ore, which is not regarded as a raw material but as waste, according to the customs statement.
The statement did not mention the origin of the 9,954.2-tonne cargo.
The cargo was impounded on October 3 during the Golden Week national holiday.
Over the past few months, copper concentrates have been highly sought after, due to tight spot availability - as tracked by Fastmarkets' copper concentrates treatment/refining charges (TC/RCs), which dropped to all-time low of $43.7 per tonne/ 4.37 cents per lb on September 4.
Lower TC/RCs mean higher procurement costs for raw materials for copper smelters.
Several of China’s major copper smelters ship material through Fangchenggang.
Customs officials in southern China have impounded just under 10,000 tonnes of copper ‘concentrates’ after it turned out to be smelting waste, which is prohibited from entering the country.