School of Minerals Processing & Bioengineering, Central South University, Changsha 410083, PR China.
School of Minerals Processing & Bioengineering, Central South University, Changsha 410083, PR China.
J Hazard Mater. 2021 Apr 15;408:124438. doi: 10.1016/j.jhazmat.2020.124438. Epub 2020 Nov 2.
Conventional melting for disposing municipal solid waste incineration (MSWI) fly ash or bottom slag needed high temperature and consumed high energy. High calcium content in fly ash and high silicon content in bottom slag brought them high melting point, respectively. Based on the analysis of chemical composition and phase diagram, suitable contents, namely 30%-40% CaO, 45%-60% SiO and 10%-15% AlO, were proposed to obtain a lower-melting-point mixture system. When the mass ratio of fly ash to bottom slag was 1:5, lowest melting point can be obtained. It was 1,190 ℃, lower than that of fly ash (1,448 ℃) and bottom slag (1,310 ℃). The toxicity characteristic leaching procedure of slags obtained from low melting treatment met the leaching toxicity of Chinese standard GB 5085.3-2007, and the slags containing about 25 wt% CaO, 10 wt% AlO and 45 wt% SiO can be used for preparing CaO-AlO-SiO glass ceramics. The co-process of fly ash and bottom slag realized the low temperature melting treatment with low energy consumption.
传统的熔融处理城市固体废物焚烧（MSWI）飞灰或底渣需要高温和高能耗。飞灰中的高钙含量和底渣中的高硅含量分别导致其熔点较高。基于化学成分和相图分析，提出了合适的含量，即 30%-40%CaO、45%-60%SiO 和 10%-15%AlO，以获得较低熔点的混合体系。当飞灰与底渣的质量比为 1:5 时，可获得最低的熔点，为 1,190℃，低于飞灰（1,448℃）和底渣（1,310℃）的熔点。从低温熔融处理得到的渣的毒性特征浸出程序符合中国标准 GB 5085.3-2007 的浸出毒性，含有约 25wt%CaO、10wt%AlO 和 45wt%SiO 的渣可用于制备 CaO-AlO-SiO 玻璃陶瓷。飞灰和底渣的共处理实现了低温熔融处理，能耗低。
