Group 1 - The core issue is the heavy environmental pollution and ecological restoration tasks left behind by closed mining enterprises, particularly concerning the large volume and complex composition of abandoned slag, which poses high potential environmental risks [1] - The principle of "who pollutes, who governs" indicates that the enterprises or their rights assignees are the primary responsible parties for pollution remediation, but many of these companies are bankrupt and unable to fulfill their obligations, leading to unowned mines that local governments must take over [1] - It is essential to clarify the specific departments responsible for pollution remediation, as theoretically, the departments approving mining operations should supervise pollution control during production [1] Group 2 - A two-step strategy is recommended for the scientific remediation of abandoned slag, focusing first on risk control to achieve an environmentally harmless goal, including measures like checking the safety of slag storage, preventing dust pollution, and managing water inflow [2] - After establishing a secure environment, research into resource utilization should be gradually developed, allowing for the phased extraction of materials once industrialization is feasible, emphasizing a "first harmless, then beneficial" approach [2] Group 3 - For slag with poor resource attributes that may not be utilized for a long time, a shift in utilization strategy is necessary, such as creating artificial slopes for safe and stable storage, which can be developed for surface use without property disputes [3] - Successful examples include increasing surface soil thickness for planting local shade-tolerant economic crops and installing solar panels for a combined industrial and agricultural development model [3] - Investors must be responsible for the collection and treatment of leachate in this resource utilization model, transforming slag mountains into green and economically beneficial landscapes [3]