Current Situation Analysis of Comprehensive Utilization of Waste Incinerator Slag

Slag is an inevitable by-product in the process of domestic waste incineration, which has the characteristics of large amount of production and high resource utilization potential. With the improvement of the construction and management level of domestic waste incineration power plants in my country, the standardized and comprehensive utilization of slag has become the focus of incineration plant management. Therefore, it is necessary to investigate and analyze the comprehensive utilization project of incinerator slag, and summarize the applicable comprehensive utilization technology route and operation management suggestions, so as to provide technical support for further standardizing and improving the comprehensive utilization level of incinerator slag in my country.

1.1 Analysis of comprehensive utilization characteristics of incinerator slag

Incineration slag is an associated by-product of the domestic waste incineration process, and its production is about 20% of the incoming waste. According to the national domestic waste incineration volume of 9.3215×107t in 2017, the annual production of incineration slag is about 1.8×107t. Slag is mainly composed of ceramic and masonry fragments, stone, glass, molten slag, iron and other scrap metals and unburned combustibles. The chemical composition of slag is similar to that of siliceous mixed materials in the cement concrete industry, and the mineral composition is mainly similar to that of building natural aggregates, so it has good potential for resource utilization.

1.2 Overall situation of comprehensive utilization facilities of incinerator slag

Since incinerator slag is a general solid waste, it is far less important in domestic waste management and technical research than fly ash, leachate, flue gas, etc. At the same time, my country’s waste incineration plants basically adopt the method of entrusting third-party treatment, and the government The supervision is relatively weak, resulting in less research on applied technology related to incineration slag projects in my country, and lack of management data information. In combination with the “centralized renovation of domestic waste incineration treatment facilities” organized by the Ministry of Housing and Urban-Rural Development from 2017 to 2018, this research group conducted a data survey on the slag treatment of 125 incineration plants across the country. The results show that there are 102 incineration plants for comprehensive utilization of slag, 19 for landfill treatment, and 4 for cement plants. It can be seen that more than 80% of the slag in my country has been comprehensively utilized.

In order to better understand the comprehensive utilization technology of slag and the operation of the project, through consulting industry experts, major waste incineration investors and some urban sanitation authorities, 6 typical projects with relatively good construction and operation management levels were finally selected for on-site investigation. , the basic information of the project is shown in Table 1. In general, the research project can basically achieve the timely treatment of incoming slag and stable sales of comprehensive utilization products; in terms of technical process, wet separation pretreatment process is adopted, and the main products are non-burning bricks and substitute aggregates. ;In terms of production management, there are big differences in the construction of production facilities, equipment maintenance, plant environment, and labor protection for workers. Some projects have the same level of construction and management as incinerators, while most projects are still at a relatively low level; in terms of government supervision , government supervision mainly focuses on the amount of slag entering and leaving the factory, and less involved in the production process.

Comprehensive utilization of slag is a kind of project with low technical level requirements, and no accumulation of slag or products is the most basic requirement for such projects.