Do Tongling nonferrous metals belong to state-owned enterprises?

Yes

Tongling Nonferrous Metals Group Holding Co., Ltd. is a state-owned enterprise, originally directly under the central government, and later placed under the management of Anhui Provincial People's Government and directly supervised by Anhui Provincial State-owned Assets Supervision and Administration Commission. In 2006, it was restructured into a modern corporate enterprise group, but it still belongs to the category of state-owned enterprises. 36.53% of its shares are held by state-owned controlling shareholders.