Principle and method of soil reconstruction for coal mine land reclamation

Soil reconstruction is the kernel of land reclamation. Many countries have enacted some laws and regulation to force the mine operators to restore a good soil condition for high productivity of reclaimed land. This paper summarised the concept, philosophy and contents of soil reconstruction and developed a general principle of soil reconstruction for coal mine land reclamation based on these laws and regulation and some good reconstruction practice. Soil reconstruction is the process or activity of reconstructing a suitable soil profile and landscape (landform) for end-use of disturbed land. The aim of soil reconstruction is for renewal of productive capacity of the land and environmental and aesthetic values. The reconstruction of optimum root medium is its focus, and keeping a similar order of original soil profile is needed. Soil reconstruction has a nature of civil engineering and mainly includes two types of tasks: reconstruction of soil profile and reconstruction of landform. A basic principle of soil reconstruction was presented, which called “strip overburden by layers and replace the individual layers in serial positions (a special order)”. The principle of soil reconstruction for two layers’ overburden was developed first as the simplest example by the description of equations and charts. Then a general principle of soil reconstruction was presented by equations and charts. By using this principle, a reconstruction method for surface coal mining and reclamation by Cross-Pit System (CPS), which is widely used in the many countries, was summarised, and a new reconstruction method for reclaiming subsidence land by Hydraulic Dredge Pump (HDP) was developed.