Research On Evaluation Models For Abandoned Coal Mine Reutilization And Their Applications

In recent years,the number of abandoned coal mines in China has increased sharply due to resources exhaustion,unsafe mining conditions and other policies,and most of them are abandoned underground mines.China has directly discarded most of coal mines after they were closed and without any reutilization.However,there are still a large number of available resources in abandoned mines.This practice not only results in severe resource waste,but also brings about a series of social,security and environmental problems.Therefore,in the context of tighter resources and environmental constraints and continuous efforts to cut overcapacity,activating the potential and vitality of the idle resources of abandoned coal mines has become an urgent problem to be solved.In view of the fact that abandoned coal mines reutilization in China is still in primary stage and basic research is very scarce,this paper regards abandoned underground coal mines(hereinafter referred to as “abandoned mines”)as the research object and takes potential evaluation,value analysis,model selection,model optimization as a master clue to research the reutilization evaluation and reutilization mode selection of abandoned mines.Firstly,with the Drive-State-Response(DSR)model and normal cloud model,the characteristics of abandoned mine reutilization potential and regional spatial layout were revealed.Secondly,focusing on the ecological service value of abandoned mines,an evaluation model for the reuse value of abandoned mines was constructed.After that,this paper proposed a logical deduction method named “condition–pattern” to select the preliminary reutilization mode of abandoned mine from constraint conditions and the degree of constraint,which suggests a stepwise integration approach to generate a more promising subset of inference results.Based on the risk management theory system,a closed mine risk evaluation framework and evaluation method were established.Then,from the perspective of risk treatment,the optimization theory of abandoned mine reuse mode was put forward combined with multidimensional decision analysis method.Finally,this paper analyzed the factors restricting the abandoned mine reutilization and put forward the targeted policy suggestions accordingly.The main conclusions are as follows:(1)This paper constructed a comprehensively assessment framework for abandoned mine reutilization potential based on the Driving force-State-Response(DSR)model.On this basis,this article employed the cloud model to quantitatively evaluate three dimensions and used the four-quadrant method to couple results.From the perspective of space control,this paper proposed 5 reutilization potential levels and 8reutilization sequence types and summarized the emphasis of policy implementation for each category.The paper regareds the 25 coal-producing provinces of China as the subject and studies the reutilization potential of abandoned mines from provincial perspective.The results indicated that the regional abandoned mines have high resource potential and strong reutilization drivers in the northern and western regions with abundant resources.However,the spatial pattern of the suitability of development conditions is not distributed in the same way as the resource.It declines obviously from the southeast to northwest.The distribution of abandoned mine reutilization potential reveals that the eastern and east-central regions should give priority to the construction of demonstration projects.Different driving force scenarios confirm that most provinces have no obvious driving factors preference with a few exceptions.This research is helpful to promote the formation of a national scale of abandoned mine zoning reutilization.(2)Focusing on the ecological service value of abandoned mine reutilization,this paper constructed an evaluation index system of the abandoned mine reutilization value including the resource conditions,ecological conditions and development conditions.In view of the lack of standards for the classification of abandoned mine resources,this paper divided the utilization method into three categories as energy utilization,resource utilization and functional utilization according to the different reutilization directions of abandoned mines resources,and adopt the minimum factor method combined with the grading method to classify the abandoned mine resources into three categories:comprehensive high-quality resources,individual high-quality resources and general resources,which formed a resource order that gives priority to comprehensive highquality resources and then takes into account specific resources with outstanding advantages.On the basis of the analysis of the abandoned mine reutilization value connotation,the viewpoint that the abandoned mine reutilization should be based on the ecological restoration and then give consideration to the social value and and economic benefit is put forward.After that,with the double criteria of resource development order and value priority order,this paper divided the abandoned mines reutilization value into four levels,commented on the difference between value evaluation and suitability evaluation,and provided criteria for project site and demonstration project selection.Based on this,this paper divided the development depth into three stages as: primary,intermediate and advanced and denoted the 5R principles for comprehensive utilization of abandoned mine resources,which provides a stepwise development strategy for abandoned mines.(3)This paper classified the reuse modes into 6 types with 19 sub-patterns according to the dominant function of the available state of abandoned mines:agricultural ecology mode;resource development mode;tourism,education and entertainment mode;social service mode;underground storage mode;and emerging industry mode and generalized the influence conditions into 3 categories with 17 subindexes,including mine conditions,natural and geological conditions,and supplementary conditions.A logical deduction method named “condition-mode” was proposed from the constraint conditions and their degree of constraint to select the preliminary reutilization patterns of abandoned mines.Finally,a practical example of the Beijing west mining area was introduced to demonstrate the applicability and feasibility of the proposed method.The results indicate that this method can select some potential reuse patterns for abandoned underground coal mines.The most important implications are that the significance of more detailed analyses and techno-economic appraisals on multiple schemes from these decision results,which suggests a stepwise integration approach to generate a more promising subset of inference results.(4)This study proposed an integral framework for mine closure risk management and presented a novel risk assessment method based on the two-dimensional cloud model,which fully considers the uncertainty in risks themselves and in the reasoning process.Compared with other risk assessment methods,the proposed method comprehensively considered the uncertainties of risk grading by clouding the risk probability and consequences,thereby realizing soft classification of the level of risk events.Combined with expert group decision-making,this method effectively integrates the fuzziness and randomness of qualitative concepts,which achieves the transformation between quantitative description and qualitative concept.On this basis,this study deduced the uncertainty reasoning process based on constructing a rule base.From the perspective of mine closure risk management,this paper proposed an optimization method of mine closure reuse mode by using multidimensional decision theory.This step is an effective supplement and further deepening to the preliminary screening of the research on the reuse mode.The results of a case study showed that this risk management methodology can help budget planning for risk treatment and provide an instructional framework to effectively reduce the negative effects of closed mines.