摘要：

采用复合改性剂〔NaOH或Al（OH）₃+粉煤灰〕在高温下对钢渣进行改性，探究了碱熔融温度、碱熔融时间及碱掺量等因素对改性钢渣吸附铅离子性能的影响，并结合XRF、XRD、SEM和BET等测试方法，对改性钢渣的化学成分、矿物组成、微观结构及孔径进行分析，并考察了最优条件下制备得到的改性钢渣的重金属浸出毒性，对铅离子吸附的再生性及选择性。研究结果表明，在碱熔融温度700 ℃，碱熔融时间4 h，钢渣、粉煤灰和碱性改性剂Al（OH）₃质量比100∶10∶20条件下，吸附铅离子效果最佳。改性钢渣没有生成新的晶体，只是破坏了钢渣中原有的晶体结构，生成了具有一定活性的多孔硅酸铝盐，表面松散堆积细小熔融颗粒，孔径集中分布在5~20 nm，在孔的吸附、化学沉淀和离子交换等反应共同作用下，对废水中铅离子的吸附率达98.15%，且具有较好的再生性和选择吸附性，是一种绿色安全的重金属离子吸附剂。

关键词: 钢渣, 改性, 吸附剂, 铅离子

Abstract:

A modified steel slag adsorbent was prepared with composite modifier(NaOH or Al(OH)₃+fly ash) at high temperature. The effects of alkali melting temperature, alkali melting time and alkali doping on the adsorption performance of Pb(Ⅱ) was investigated. Chemical composition, mineral composition, microstructure and pore size was analyzed with XRF, XRD, SEM, BET and other methods. The heavy metal leaching toxicity, regeneration ability and selectivity of the modified steel slag prepared under the optimal conditions were investigated. The results showed that the best adsorption of Pb(Ⅱ) was achieved under the conditions of 700 ℃ alkali melting temperature, 4 h alkali melting time and 100∶10∶20 mass ratio of steel slag, fly ash and Al(OH)₃. There was not new crystal in the modified steel slag, but the original crystal structure was destroyed, and porous aluminum silicate salt with certain activity was formed. Loose fine molten particles were accumulated on the surface of steel slag, and pore size was concentrated in the range of 5-20 nm. Under the combined effect of pore adsorption, chemical precipitation and ion exchange, the removal rate of Pb(Ⅱ) from wastewater reached 98.15%. The modified steel slag adsorbent had better regeneration and selectivity, which was a green and safe heavy metal ion adsorbent.

Key words: steel slag, modified, removal, lead ion

中图分类号: 

• X703