The mineral resources in the city are various and complex, containing heavy metals and organic polymers. The process of urban mineral recovery includes disassembly, crushing, separation, transportation, remanufacturing and other disposal processes, and the discharge of various pollutants into the environment, such as lead, copper, cadmium and other heavy metals and organic pollutants such as polycyclic aromatic hydrocarbons (PAHs), volatile organic compounds (VOCs), brominated flame retardants (BFRS). At present, the mining technology in urban areas is still mainly processed manually, which lacks of automation and intelligence, and has problems such as low processing efficiency and health exposure risk of workers. Therefore, it is of great significance for resource recovery and circular economy construction to upgrade mineral base technology in typical cities.
This project has studied four typical urban mineral bases: waste glass base, waste household appliances base, waste automobile base and auto parts remanufacturing base. The generation and release rules of major pollutants in different links of each base were studied, and the corresponding pollution emission factor database and emission list were constructed, including more than 50 kinds of pollutants in 7 categories. Workers' exposure risk assessment and ecological environmental impact assessment were carried out, and priority control pollutants and priority control links were selected to provide basic environmental data for technology upgrading.
For the recycling of waste glass, following the research idea of "Industrial 4.0 green and intelligent technology upgrading and integration", the following studies were carried out: upgrading the green, intelligent and efficient sorting technology and equipment of waste glass; Development of waste glass waterless cleaning, intelligent and precise classification, efficient sorting and impurity removal technology and equipment, to form waste glass recycling treatment green, batch scale, intelligent. A technical standard system with independent intellectual property rights that integrates green, intelligent and information will be established, and a new model of intelligent classification and composite sorting of waste glass in urban mineral base will be constructed.
In view of the backward treatment of waste household appliances and automobiles, which is combined with manual dismantling and mechanical disposal, automation equipment has been developed, focusing on the application and industrialization of intelligent dismantling technology, and focusing on the research and development of intelligent dismantling technology, intelligent transportation technology, intelligent storage technology, fluorescent powder intelligent cleaning technology with the direction of automation and mechanization control of dismantling line. To realize the intelligent and fine dismantling of waste household appliances and automobiles, two project demonstration lines have been built: intelligent disposal line of waste CRT display and automatic intelligent dismantling line of waste automobile.
In view of the common technical bottlenecks in remanufacturing of high-value and precision parts such as automatic transmission, steering gear and engine in scrapped vehicles, such as chemical and physical cleaning environment has a large impact, the cleaning effect of complex parts is not good, and the remanufacturing rate is low. Green cleaning technology and equipment represented by laser cleaning are developed. The remanufacturing material system with abrasion resistance, corrosion resistance and fatigue resistance is developed. High-speed laser additive remanufacturing technology is adopted to realize high-speed laser micro-additive precision remanufacturing of damaged parts and improve the remanufacturing rate of high-value automotive parts and solid waste. The demonstration of solid waste remanufacturing project of high-value auto parts was carried out by taking the waste transmission with large amount of scrap, high import dependence and strong reuse as an example.
This project builds a big platform for environmental protection management of urban mineral base, realizes the information management of urban mineral resources, and carries out accurate statistics and analysis of urban mineral resources in production, sales, use, inventory, scrap and recovery. At the same time, the commercial operation mode of urban mineral base is established, and the systematic commercial analysis of the recovery of low-value, middle-value and high-value urban mineral is carried out, including market and policy analysis, process and equipment analysis, cost and profit analysis.
