Endogenizing Ecological Cost In Open Pit Coal Mine Design

With the constant development of China’s economic construction,the coal mining industry has made tremendous progress. According to the National Bureau of Statistics, China’s raw coal production has reached a historical high of3.65billion tons in2012. Accompanied by the development of the coal industry, lots of environmental problems caused by coal mining have been increasingly apparent. For these urgent problem,our country has also introduced a number of policies and regulations requiring mine land reclamation and ecological restoration.However, pollution control and land reclamation are passive and "End-of-pipe" measures. Even some of the damage caused by mining is unrecoverable. The idea of "Source Reduction" is to reduce consumption of natural resources before the process of production and consumption. On the one hand,this can reduce the resource consumption in resource acquisition process. On the other hand, this can reduce the destruction of waste emissions on the environment in the process of production and consumption.The idea raises the concept of design for the environment. The new design mode emphasis on considering the maximum possible to reduce environmental impact at the design stage.So far, we usually regard the damage to the environment as essential external diseconomies in the mining design of opencast coal mine. But I think that we should measure the ecological costs of damage caused by mining at the design stage. And we should endogenize the ecological costs to the mining costs. This design method can effectively limit the uncontrolled expansion of production capacity. It can educe the damage and impact of coal mining on the ecological environment in the beginning.To study on the influence mechanism of environmental cost in mining design, this paper sequentially describes the coal seam and surface models’ construction algorithm. Based on the above model, it elaborate the generation algorithms of maximum candidate boundary and series of candidate ultimate pits. Finally, it elaborate the algorithms of mining plan optimization. Basically, this article has already establish the entire optimization design methodology which is in line with the idea of "source reduction". In order to clearly measured the degree of the impact on the environment, we should calculate the ecological cost. Based on the service functions of grassland ecosystem and combined with the ecological footprint theory, the econometric model of ecological cost for opencast coal mine has been roughly established. The model includes the computing theory and formulas of energy costs, reclamation costs, direct economic losses and external ecological cost.The CoalMiner which is developed based on the theory in article, has been applied to optimize or design the ultimate pit of an opencast coal mine in Inner Mongolia. The coal seam and surface columnar model have been established according to the geological data of the opencast coal mine. Based on the model,15small to large candidate ultimate pits have been produced. Then, optimize the mining plan for each boundary and calculate the ecological cost of each boundary. At last, the total present value of each boundary after endogenizing the ecological cost will be obtained. Through a comparative analysis, we will get the optimal ultimate pit which has already considered the environmental cost.