协同利用提锌二次窑渣和疏浚泥制备陶瓷的工艺优化  

Optimization of synergistic preparation process of ceramics from zinc extraction secondary kiln slag and dredging mud

作　　者：王治飞 李宇 WANG Zhifei;LI Yu(State Key Laboratory of Advanced Metallurgy,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]北京科技大学钢铁冶金新技术国家重点实验室,北京100083

出　　处：《钢铁研究学报》2023年第2期210-218,共9页Journal of Iron and Steel Research

基　　金：国家重点研发计划资助项目(2019YFC1905705)。

摘　　要：针对沿海钢铁产业聚集区冶金粉尘提锌后排放的大量二次窑渣以及港口河道等疏浚过程排出大量疏浚泥难以利用的现状,根据窑渣高铁高钙和疏浚泥高硅高铝的组分特点,协同利用二次窑渣和疏浚泥制备建筑陶瓷,并采用X射线衍射分析、傅里叶变换红外光谱、扫描电子显微镜和电感耦合等离子体质谱仪测定不同组成(窑渣和疏浚泥比例从60∶40增加到80∶20)和不同工艺条件制备陶瓷样品的矿物组成、微观结构和重金属浸出浓度等性能。研究结果表明:在最佳烧成条件下(窑渣∶疏浚泥质量比为70∶30,焙烧温度为1 180℃,焙烧时间为40 min,预热温度为500℃,预热时间为10 min)烧制陶瓷的性能优良,其中,抗折强度为85 MPa, 1 h吸水率为0.15%,表观密度为2 180 kg/m3,陶瓷中Cr、Mn、Ni、Cu、Zn和As等重金属元素的浸出结果满足国家标准要求。该窑渣-疏浚泥陶瓷的主要矿物为普通辉石相,其次是赤铁矿,其中辉石相粒径为2~5μm且大量均匀析出,有利于提高其力学性能。陶瓷在致密化过程产生了液相烧结,这使得整体结构致密,吸水率低,有利于对重金属元素的固结。The large amount of waste secondary kiln slag generated after extraction of zine from metallurgical dust every year, and the huge dredged mud was also discharged during the dredging process of the port and river channels in the coastal iron and steel industry agglomeration areas. For the situations that the two huge solid wastes are difficult to be utilized, they were re-used synergistically to prepare building ceramics according to their synergistical characteristics in composition, high iron and high calcium content in secondary kiln slag and high silicon and high alumina content in dredging mud. By aid of X-ray diffraction analysis, Fourier transform infrared spectroscopy, scanning electron microscopy, inductively coupled plasma mass spectrometry and test of heavy metal leaching concentration, bending strength and water absorption ratio, the mineral composition, microstructure and physical properties of ceramic samples under proportion between kiln slag and dredged mud from 60∶40 to 80∶20, and different sintering conditions were further determined. The results show that the optimal sintering conditions for the ceramics was the mass ratio of 70∶30 for between kiln slag and dredged mud, the roasting temperature of 1 180 ℃, the roasting time of 40 min, the preheating temperature of 500 ℃ and the preheating time of 10 min. Under the optimal conditions, the ceramic had qualified properties with bending strength of 85 MPa, 1 h water absorption rate of 0.15%, apparent density of 2 180 kg/m~3 and an excellent leaching rate of heavy metal elements, Cr, Mn, Ni, Cu, Zn and As according to the national standard. Its main crystals were pyroxene and hematite. The pyroxene had a much fine size of 2-5 μm and homogenous distribution in ceramics, which was contributing to its excellent properties. Occurrence of liquid sintering in the ceramics during roasting process resulted in an overall compact structure and very low water absorbed rate, which was in favor of its low heavy metals leaching rate.

关 键 词：窑渣 陶瓷 烧结条件 辉石 赤铁矿 

分 类 号：X756[环境科学与工程—环境工程]