Sustainable development of mines and reuse of tailings

0 Preface

In 2008, the US financial crisis triggered a global economic crisis, China's economy also showed a downward trend. To stimulate domestic demand, China has taken to invest in all types of highway, railway, subway and other infrastructure, encourage research and development and production of new building materials and a variety of energy conservation and new materials, new products. These projects require a large amount of raw materials. How to make effective use of existing resources and turn waste into treasure is a common concern in the industry. China currently has accumulated a large number of mining tailings, waste rock, coal gangue, etc., total over a hundred million tons. The accumulation of these tailings waste rock requires not only a large amount of maintenance costs, but also a large area of ​​land occupation, and damage to the ecological environment, and even poses a threat to the personal safety of downstream residents. Resource-based development of mine tailings waste rock, turning waste into treasure, not only saving resources, reducing energy consumption, but also meeting the demand for building materials brought about by China's economic and social development, is conducive to improving the ecological environment and promoting the sustainable development of the mine.

1 Basic situation of tailings storage

1.1 Current status of tailings storage Tailings are “wastes” discharged by mining and dressing enterprises under certain technical and economic conditions, but at the same time they are potential secondary resources. Once technical and economic conditions permit, they can be effectively developed and utilized again. .
The characteristics of China's mineral resources are associated with more ore, more difficult to mine, more poor ore, and more small ore. There are many mining enterprises, and a large number of tailings are produced each year. According to statistics, before 2000, the total output of tailings produced by mines in China was 5.026 billion tons, of which iron ore tailings were 2.614 billion tons, the main non-ferrous metal tailings was 2.109 billion tons, and the gold tailings were 2.72. Billion t, the other 0.31 billion t. In 2000, China's mines exported 600 million tailings per year. According to this calculation, the total amount of existing tailings is about 10 billion tons. Due to the late start of mining in China, the technology development is not balanced, and the technology of metallurgy in different periods is very different. lot of valuable resource to reside in the tailings data show: gold content gold tailings typically 0.2-0.6g / t, iron total iron mine tailings grain bits to 8% -12%, copper ore tail 0.02% -0.1% copper ore, lead and zinc mine tailings containing lead and zinc 0.2% -0.5%. occurrence of considerable tailings resource, in the case of technical and economic conditions permit *, the second for the full development of the tailings resource The use of non-renewable mineral resources is of great significance.
1.2 Hazards of tailings stockpiling At present, only a small amount of tailings in China has realized the reuse of resources. Most of the tailings are discharged into low-lying areas for storage, which not only occupies a large amount of land, destroys the ecological environment, but may also cause tailings dam dam failure. To cause harm to the lives and property of the downstream people. On September 8, 2008, the dam accident in Shanxi Taiwei Mine caused heavy casualties. The media reported that there were many tailings dams and dams in Liaoning Haicheng and Shanxi Fanjia. In addition to the dam accident, there are environmental hazards caused by long-term storage of tailings. Most of the tailings ponds are built in mountainous areas. First, it destroys vegetation, changes the veins of the mountains, and affects water conservation. Second, it may cause pollution to reservoirs that are currently planned to be used as drinking water sources or backup water sources.
1.3 The main reason why tailings are not used is the reason why a large number of tailings resources are idle. First, the entry threshold of mining enterprises is low, and a large number of enterprises that do not have the qualifications for development enter the mining development field. Some mining technology and technology are backward, some small The resource recovery rate of enterprises is less than 50%. Second, the policy of encouraging the use of tailings resources has not yet been implemented. The national investment is less, the cost of developing tailings is higher, the economic benefits of enterprises are low, and the enthusiasm is not high. Lack of effective supervision, the current relevant laws and regulations only regulate the use and utilization of solid waste such as mine tailings and waste rock, and no mandatory measures are formulated.

2 The necessity and ways to realize the tailings resource

2.1 The Necessity of Realizing the Resources of Tailings On the one hand, China's per capita mineral resources are seriously insufficient, far below the world average. On the other hand, a large number of tailings are idle, so the resource and harmlessness of tailings are solved. The problem is a good thing for the benefit of the country and the people.
With the advancement of technology and the increase in the price of mineral products in the international market, tailings recovery can produce better comprehensive economic benefits and should be highly valued. The prices of mineral products in the international market continue to rise. In particular, the prices of non-ferrous metals and precious metals have risen rapidly, increasing the production costs of enterprises demanding mineral products, and at the same time increasing the pressure on resource security. At present, China is in the stage of accelerating industrialization and urbanization, with large consumption of mineral resources and high dependence on foreign countries. China is a large mining country. The development and utilization of a large number of long-term accumulated tailings can not only turn waste into treasure, but also effectively alleviate resource and environmental pressures.
2.2 Current main ways to realize tailings resource utilization At present, there are mainly the following ways of tailings resource utilization at home and abroad: a. Try to make comprehensive recovery and utilization of useful components of tailings resources, adopt advanced technology and reasonable technology for tailings. Perform re-selection to maximize the recovery of useful components in tailings and further reduce the amount of tailings; b. Use tailings as fillings for underground mining mined areas, ie water-filled or cement-filled aggregates ; c. use tailings as raw materials for building materials, making cement, silicate tailings bricks, aerated concrete, refractory materials, ceramsite, concrete aggregates, slag tiles and foam materials; d. As pavement materials, anti-skid materials and coastal field materials for road construction; e. Covering soil on the tailings dumping field, planting crops or planting trees; f. Using tailings to process plant growth organic fertilizer.

3 resource development direction of tailings

The overall development and utilization of tailings is bound to become a new resource for competing applications in the 21st century and a basic resource for strengthening national strength. Promoting the rapid development of tailings resources should mainly strengthen the following aspects: a. Form an environmental protection industry with tailings resources as the core, so that enterprises can make profits by investment, and rely on tailings development to promote the comprehensive utilization of tailings. Form a virtuous circle and make the mine an integrated resource base. b. Promote the use of tailings through engineering demonstration. The overall development and utilization of tailings is a systematic project involving a wide range of industries and technologies. There are many factors. It is necessary to accumulate experience and solve related problems through demonstration mines and demonstration projects to avoid detours, reduce investment and obtain good benefits. c. Develop and invest in a number of high value-added products and projects. At present, the development and utilization of tailings is difficult and the progress is slow. Apart from historical reasons such as the degree of understanding and social constraints, the project is currently available for development and utilization, and the economic benefits are lower than that of the main products of the mine. It is difficult to mobilize mining enterprises and The enthusiasm of the research unit. Only relying on scientific and technological progress, research and development and investment in a number of high value-added products and projects for mass production, and industrialization, can mobilize the enthusiasm of mining enterprises and the whole society, and become passive. d. Support from the aspects of fiscal taxes and policies. In order to further improve the development and utilization of tailings resources, the following measures are recommended: First, formulate and implement relevant policies, encourage and support enterprises to carry out technical research and technological transformation; implement preferential policies such as reduction and exemption of resources, taxes, fees, etc., and guide and encourage society and enterprises. Capital investment in tailings resource development. Second, we must strengthen technological innovation in the comprehensive utilization of tailings, develop advanced technologies and advanced technologies, and accelerate the transformation of research results. The third is to use the central financial funds to focus on supporting the utilization of resources for large enterprises, tailings and “waste” in large mining areas, and to play a guiding role. The fourth is to strengthen the development of quasi-person management, formulate and improve the standards for the access and supervision of mining development enterprises, promote the restructuring of enterprises, and strengthen and expand mining enterprises.

4 The importance of resource development for the sustainable development of mines

With the rapid development of science and technology, the traditional concept of mine tailings solid waste has changed from passive storage to active resource development. Practice shows that the mine tailings as a composite mineral raw material for overall development and utilization becomes an economic and practical new resource, which can not only restore the original resource depleted or resource-poor mines into a new resource base to restore or expand production, making full use of non-renewable minerals. The resources and the original mine facilities will give full play to the potential of the mines, so that the state and enterprises can obtain a large number of minerals that have been processed into fine-grain raw materials without investing in capital construction, and can provide employment for a large number of people, prosper mining and mining towns, and solve environmental pollution. Improving the ecological environment and rectifying the country has enormous economic, social and environmental benefits.

Summary: