New Process and Key Technology of Copper Tailings Treatment Become One of the Hubei Province Major Scientific and Technological Innovation Projects
Learned from Hubei Province Science and Technology Department, the “Key Technology of Efficient Comprehensive Disposal and Deep Resource Utilization of Copper Tailings” become one of the 2014 Annual Hubei Province Major Scientific and Technological Innovation Projects.
Copper tailings are rich in Cu, Au and Ag and other non-ferrous metals. By the end of 2013, the accumulated copper tailings in China was 2.5 billion tons. According to expert’s estimate, valuable elements can be recycled from the stockpiling copper tailings, with 300 tons of gold and silver, 2 million tons of copper, and many rare metals such as titanium, which would create tens of thousands of yuan output value. At present, the whole comprehensive utilization of the copper tailings are quite inadequate, especially the long-term stacking tailings, they are just simple used for mine backfill and road paving. The high value-added process ability of tailings is insufficient, which not only led to waste of renewable resources such as many valuable metals, but also second pollution caused by improper handling mode. It would bring about security risks to surrounding land, water system and ecological environment.
Aiming at the shortage of the existing design, technology and equipment in resource utilization of copper tailings, as well as non stable quality of the key products, low value-added, high investment cost and other technology bottlenecks, we have researched and developed key technology and equipment of nonferrous metal extraction from copper tailings, copper tailings regenerative slag efficient grinding process and equipment, copper tailings regenerative slag for preparation dry pressed brick, aerated concrete and other new energy saving wall materials, etc.
The project has the following major innovations:
1) The key technology and equipment of nonferrous metal extraction from copper tailings, compared with the traditional technology and equipment, we can save more than 10% energy. The high-grade copper tailings conversion technology, the copper content of converted copper resources is more than 40%, the gold content is more than 1g/t, the silver content is 20g/t, with metal recovery rate of 95%.
2) The copper tailings regenerative slag efficient grinding process and equipment, compared with the traditional technology and equipment, we can save more than 10% energy and make slag powder, with specific surface area more than 450m2/kg, and good particle size range of 5 ~ 30 μm powder.
3) The copper tailings regenerative slag for preparation of dry pressed brick, to realize resource utilization of copper tailings in common wall materials. The apparent density of the brick is not more than 1500kg/m3, strength grade is more than MU15, with utilization rate is more than 60%.
4) The copper tailings slag powder preparation of aerated concrete, to realize the application of copper tailings in energy-saving wall materials, the apparent density of aerated concrete is not more than 500kg/m3, 28d compressive strength is more than 5MPa, with utilization rate of more than 40%.
The technical research achievements of this project can not only save mineral resources, improve the utilization rate and enlarge the use range, but also save a lot of land resources, efficiently reduce environmental load to realize the unity of resource benefits, economic benefits, social benefits and environmental benefits. What’s more, the technology would enable industrial upgrading of the mines, building materials and other related industries, enhance the core competitiveness and development potential of enterprises, which make sure them in the leadership position in the new round of industrial innovation in the future, and promote the rapid development of “Waste Recycling Industry Chain”.