A Study On Soil Restructure Technologies For Surface Coal Mine In Arid Grassland

Arid grasslands are not only the main body of China's northern grasslands but also the hardest hit by environmental degradation. Now the exploitation of resources is one of the current main reasons of severe destruction to arid grasslands. In recent years, the surface coal mining in Inner Mongolia have a rapid development, but the mines are usually located in Ecologically fragile areas, so open-pit mining not only brings huge economic benefits but also seriously destroys fragile ecological environment of grassland. So how to do the restoration and reconstruction work after the exploitation of resources on environment will be the study focus in a very long time. This paper, based on a case study on the dump of No.2 surface coal mine in ShengLidong mining area in Inner Mongolia, is to provide a reference for the similar lands through analyzing and researching the technologies of Soil Reconstruction.Methods employed in the study contain comprehensive analysis of materials, field plot survey and comparative analysis. There are three main research areas: (1) studying the relevant basic theory of Soil Reconstruction and the whole process of Soil Reconstruction theory; (2) summarizing and analyzing the limiting factors related to Soil Reconstruction; (3) verifying and innovating the Soil Reconstruction technologies from limiting factors, Research summary of soil reconstruction, validation to propose the most suitable technologies for the study area.Through research the following conclusions:(1) Establishing a technical system for Soil Reconstruction and the system is divided into three stages which include Soil Reconstruction preparation section, Soil Reconstruction implementation period and Soil Reconstruction maintenance stage. The first stage includes topsoil stripping, topsoil storage; the second period includes soil profile reconstruction, soil improvement and plant selection and configuration; the last includes soil and water conservation, labor management and protection.(2) Summarizing and analyzing six main limiting factors to Soil Reconstruction, which include low soil fertility, heavy metal pollution, lack of topsoil, water shortages, less desirable species and severe soil erosion. (3) Detailed study has been done to each technical part and technical guidelines are also established. In details, the thickness of topsoil stripping is designed by 30cm with mechanization; if land size in the unrestricted case, the topsoil storage should be piled up into heaps; dump is piled up by layered construction, the mixture of soil and rocks - clay - sandy loam layer from the bottom to top; covering topsoil is mainly in the form of conical heaps, the design size: basal area about 25m~2, height 1.0 ~ 1.5m, and the volume is about 8m~3; the methods of soil improvement are planting green manure and using fertilization; selected species based mainly on the local pioneer species and the configuration mode contains herb, bush and arbor; soil erosion is mainly prevented by intercept and drainage engineering project; human management and protection include covering straw mat and setting the grass grids, and establishing ecological monitoring system.