硼硅比对飞灰玻璃化过程Cr固化赋存形态的影响

以垃圾焚烧厂产生的焚烧飞灰、钢渣、铬渣为主要原料,采用熔融玻璃化方法制备出CaO-SiO_2-Fe_2O_3体系低熔点玻璃固化体。采用X射线荧光光谱(XRF)、X射线衍射仪(XRD)、扫描电子显微镜(SEM)、电感耦合等离子体原子发射光谱仪(ICP-AES)等分析测试手段研究了硼硅比对垃圾焚烧飞灰玻璃化的影响,考察了不同硼硅比时固化过程Cr赋存形态的变化规律以及Cr的固化稳定性。结果表明,硼与飞灰中高钙形成硼酸钙低熔点矿物相可使飞灰的熔化温度从1 300～1 600℃显著降到950℃;增大硼硅比可抑制铬钾矿的形成,最终形成玻璃体包裹负载Cr的尖晶石相;采用HJ/T 299—2007 《固体废物浸出毒性浸出法—硫酸—硝酸法》评价玻璃固化体的固化稳定性,Cr离子的浸出浓度为0.47mg/L,远低于国标限值。采用飞灰熔融法制备的低熔点玻璃固化体可以将重金属元素Cr稳定固化。

Preparation of low-melting glass from waste incineration fly ash and solidification of heavy metalsYU Yue-long1,2,3 YUE Chen-xi2,3 CAO Jian-wei2,3 WANG Zhi2,3 QIAN Guo-yu2,3 WU Ji-jun1

Using the incineration fly ash produced by the garbage incineration plant, steel slag, and chromium slag as the main raw materials, the CaO-SiO2-Fe2O3 system low-melting glass solidified body is prepared by the melting-vitrification method. Through XRF, XRD, SEM-EDS and other analytical testing methods, the effect of borosilicate ratio on the vitrification of waste incineration fly ash, the borosilicate ratio on the morphological changes of Cr solidification process and the solidification stability of Cr were studied. The results show that the melting temperature of fly ash is significantly reduced from 1300 °C ~1600°C to 950 °C due to the formation of calcium borate low melting point mineral phase between boron and high calcium in fly ash; It was found that increasing the ratio of boron to silicon can inhibit the formation of lopezite. Eventually form a spinel phase containing Cr,the spinel is encased in the glass body; Sulfuric acid and nitric acid method is a solid waste leaching method. It is used to evaluate the curing stability of glass cured body. The leaching concentration of Cr ions is 0.47mg/L, which is far lower than the national standard limit.