The main problems and solutions of mine ecological restoration

1.3 There are misunderstandings in the field of mine ecological restoration engineering

The large-scale development of mine ecological restoration project makes the construction team of different good and bad pour into the field of mine ecological restoration. Related engineering construction teams lack systematic, holistic and scientific understanding of mine ecological restoration, coupled with insufficient knowledge reserve and limited technical level, some people think that mine ecological restoration projects are earthworks of digging MATS. For example, they think that covering exposed rocks with soil and filling in subsidence pits is simple and arbitrary, and many cases of failure after restoration are reported. The phenomenon of "one year green, two years yellow, and three years dead" often occurs. If the soil reconstruction is ignored in the process of filling or covering, the water-soil-vegetation will not form a good circulation body, and the vegetation will not live without water and nutrition, and it will be exposed again after 1 to 2 years. When modifying slopes such as dump and stope, if the principle of imitating natural landform is not scientifically applied and the slope is not integrated with the local natural environment, the maintenance cost will be high, and the long-term stability will be poor, resulting in more serious soil erosion and landscape fragmentation [4]. For example, when acid gangue mountain is controlled, fire suppression is not allowed, fire prevention measures are not in place, and the reignition rate is as high as 50%. Figure 1 shows the difference of the landform remodeled into nature in the opencast mine dump. Therefore, the mine ecological restoration project needs scientific and technical support.

1.4 Difficulties in popularizing and applying new technologies

After more than 40 years of practice and research, the majority of scientific researchers have developed a variety of ecological restoration technologies, but the promotion and application of new technologies are limited. At present, China's mine ecological restoration mainly depends on government investment, especially the old account problem, and the social investment is little, so the funds are limited. And some new technologies in order to achieve better repair results, the cost will be increased. For example, compared with soil reconstruction technology, extensive one-time excavation and filling and "layered stripping and staggered backfilling" according to the needs of vegetation growth, the latter investment is slightly larger, and the application enthusiasm of construction enterprises is not high. Another example is the mining side recovery technology of coal mining subsidence, because it is constructed when the ground is not stable, it needs to reserve the subsequent subsidence elevation, which means that the ground is not smooth during the project acceptance and can not meet the traditional acceptance requirements. Construction enterprises and local governments are reluctant to use this technology, and the resulting loss of soil resources is very helpless. Therefore, it is very important to promote the promotion of new technologies, and it is necessary for managers and builders of mine ecological restoration to change their thinking and achieve breakthroughs in investment and policies.

2. Countermeasures for mine ecological restoration in China

2.1 Principles to be followed for mine ecological restoration

Mine ecological restoration is not only the restoration of damaged terrain, simple greening and so on. Mine ecological restoration is a systematic project, which is a complex project integrating damage investigation, design planning and construction. In order to achieve the result of restoring the damaged ecology, it is necessary to have a deep understanding of the connotation of the restoration goal. At the beginning of the planning, it is necessary to clarify the use of land use after restoration, the ecological structure and the ecological function that should be realized. Therefore, the goal setting of mine ecological restoration needs to comply with the following six principles: respect for nature, people-oriented; Adapt to local conditions and conform to the overall regional planning; Safe, efficient and sustainable use; Priority should be given to ecological and environmental benefits, and attention should be paid to economic benefits. Priority is given to restoring cultivated land, grassland and forest land; End treatment is combined with source and process control.

2.2 Strengthen the basic research of mine ecological restoration

The practice of mine ecological restoration for more than 40 years shows that the restoration theory lags far behind the practice, and many restoration cases fail due to lack of scientific restoration, which shows that there is a decoupling phenomenon between theory and practice. In order to repair the ecological environment damage caused by mining, many places have carried out spontaneous restoration and utilization of the damaged land and ecological environment. For densely populated areas with rapid economic development, mine ecological restoration is often promoted faster. However, the basic theory of this field and the principles of restoration technology still need to be deeply studied to support and promote the development of this field.