不锈钢含铬除尘灰制备玻璃化产物的危险特性与性能

为降低危险废物不锈钢含铬除尘灰的危险特性及处置利用过程中的生态环境污染风险，采用国际先进的高温熔融玻璃化处置技术，实现含铬灰中毒害组分的安全转化及资源化利用目标.以不锈钢含铬除尘灰危险废物作为研究对象，通过掺杂不同质量比例的硅藻土、膨润土、氧化钙及氧化铝控制生料的碱基度，在不同熔融温度、不同保温时间下制备玻璃化产物，即玻璃体，并对玻璃体的危险特性及资源化利用的物理化学性能进行研究.结果表明:不锈钢含铬除尘灰中主要重金属是Cr、Ni、Mn，经掺杂无定形结构调制剂，在熔融温度为1 450℃、保温时间为0.5 h、碱基度控制为0.14~0.55时，可以制备出微观结构致密、连续性好、孔隙率低、表面光滑的玻璃体；玻璃体中的Cr与Ni经玻璃化处置后，采用HJ/T 299—2007《固体废物浸出毒性浸出方法硫酸硝酸法》与HJ/T 300—2007《固体废物浸出毒性浸出方法醋酸缓冲溶液法》测得的Ni、Cr的浸出毒性远低于GB 5085.3—2007《危险废物鉴别标准浸出毒性鉴别》与GB 16889—2008《生活垃圾填埋场污染控制标准》对固体废物入场的限值要求；玻璃体结构致密、力学强度高，碱基度为0.14~0.55的玻璃体坚固性范围为1.1%~4.5%，压碎值范围为3.4%~7.5%，满足JGJ 52—2006《普通混凝土用砂、石质量及检验方法标准》中用砂对坚固性与压碎值分别不超过8%与30%的质量要求；玻璃体的渗透系数为10-9~10-8 cm/s，满足填埋场防渗替代材料的渗透系数要求.研究显示，利用不锈钢含铬灰制备玻璃体前后重金属浸出毒性及危险特征明显降低，可以实现无害化处置，玻璃体的物理化学性质与防渗效果满足混凝土用砂等潜在应用场景的性能要求. 

Performance and Hazardous Characteristics of Vitrification Product of Chromium Dust from Stainless Steel

In order to reduce the hazardous characteristics of chromium dust generated in the production of stainless steel, and reduce the ecological environment pollution risk in the process of disposal and utilization, advanced vitrification technology is adopted to treat chromium dust hazardous waste. Vitrification is considered as a promising technology for management of hazardous waste, and it achieves the goals of reduction, innocent treatment and resource utilization. This study focused on the utilization of the chromium dust from the manufacture of stainless steel. Various proportions of diatomite, bentonite, quicklime and aluminum oxide were adjusted to control the alkalinity of the raw materials, and different melting temperatures as well holding times were set to prepare glassy products. The results showed that the main heavy metals in the chromium dust were Cr and Ni. By means of an appropriate technique (temperature, 1450 ℃; holding time, 0.5 h; alkalinity, 0.14-0.55), a vitrified product characterized with dense and homogenous structure, low porosity and smooth appearance could be made. Compared with Solid Waste-Extraction Procedure for Leaching Toxicity-Sulphuric Acid & Nitric Acid Method (HJ/T 299-2007) and Solid Waste-Extraction Procedure for Leaching Toxicity-Acetic Acid Buffer Solution Method (HJ/T 300-2007), the toxic substances in the finished samples were lower than the limits of Identification Standards for Hazardous Wastes-Identification for Extraction Toxicity (GB 5085.3-2007) and Standard for Pollution Control on the Landfill Site of Municipal Solid Waste (GB 16889-2008), respectively. Furthermore, the vitrified product had excellent physical and mechanical properties (robustness value, 1.1%-4.5%; crushing value, 3.4%-7.5%), which was lower than the limits in Standard for Technical Requirements and Test Method of Sand and Crushed Stone (or Gravel) for Ordinary Concrete (JGJ 52-2006). Therefore, this vitrified product could be used as an alternative impermeable material for landfills since it has excellent impermeability, and the permeability coefficients ranged from 10-9-10-8 cm/s. The research showed that after the vitrification treatment, the heavy metal leaching toxicity and hazardous characteristics of the vitrified samples are significantly reduced, which can achieve harmless disposal. The physical chemistry properties and anti-seepage effect of the vitrified material meet the requirements of potential application scenarios such as concrete sand and alternative impermeable materials.