Six university students drowned on Wednesday while on a field visit to a copper-molybdenum mine in northern China, owned by Shanghai-listed Zhongjin Gold Corp.
The students from Northeastern University in Shenyang fell into a flotation cell - a piece of mining equipment that uses a liquid solution to extract copper from crushed ore - after protective grates collapsed.
A teacher was also hurt in the accident at the mine located in China's Inner Mongolia region, according to a stock exchange filing from Zhongjin Gold, a subsidiary of state-owned China National Gold Group Co.
The company said it activated an emergency plan and reported the incident to the relevant departments of the local government.
The operator of the mine, a subsidiary of Zhongjin Gold, halted production, the company said in another stock exchange filing later on Thursday.
Such field visits have been organised for years and the incident was unexpected, said a teacher from Northeastern University, according to a social media account belonging to Henan Radio and Television.
The university sent staff to the site to manage the incident, the teacher said.
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