Immobilization by sulfuration of waste heavy metals

废弃重金属的硫化固定化

基本信息

批准号：
13450316
负责人：
MATSUDA Hitoki
金额：
$ 0.83万
依托单位：
Nagoya University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2002
项目状态：
已结题

项目摘要

The present study is concerned with a novel method to immobilize and deposit heavy metals contained in fly ash from waste incineration facilities.The toxic heavy metals such as lead and zinc are present as soluble compounds in fly ash such as metal chlorides and oxides. This study was based on the fact that heavy metals naturally exist as insoluble sulfides and that asphalt is water-repellent. We propose the physical and chemical immobilization of waste heavy metals by mixing with asphalt, sulfur and alkaline agents-sodium hydroxide and calcium hydroxide, in a bi-axial kneader heated at 403-523K.Calculations on the Gibbs' free energies showed that sulfuration of heavy metals resulted from the formation of either sodium sulfide or calcium sulfide via the reaction of sulfur with alkaline agents. Experimental results from XRD analysis of soluble metal compounds mixed with sulfur and alkaline agents also indicated that soluble metal compounds were convertable to insoluble metal sulfides only if either sodium sulfide or calcium sulfide is initially formed. It was found that the addition of sulfur and sodium hydroxide into fly ash at 403K led to the sulfuration of heavy metals. Similarly, the addition of sulfur and calcium hydroxide at 523K brought about sulfuration of heavy metals. The results of the leachability test for the treated fly ash by the proposed immobilization method indicated that leaching of heavy metals in fly ash was suppressible.

本研究涉及一种新的方法，该方法将废物焚化设施中的粉煤灰中固定和沉积重金属。这项研究是基于这样一个事实，即重金属自然作为不溶性硫化物存在，并且沥青是依赖水的事实。我们提出，在双轴揉合在403-523K加热的双轴揉合中，通过与沥青，硫和碱性盐氢氧化物和氢氧化钙混合，将废物重金属的物理和化学固定化对含量的硫酸盐或硫化硫的硫化，或者通过硫化形成的硫化是硫化的，这表明硫化是硫化的硫或硫化的，这表明硫酸的硫化是硫化的，硫化是由硫化或硫化的，硫化物的自由能是硫化的，或者是硫化硫的形成或硫化的，这表明硫磺是硫化的硫酸盐或硫化，这表明硫磺是硫化的硫酸盐或硫化含量。硫与碱性药物的反应。 XRD分析与硫和碱性剂混合的可溶金属化合物的实验结果还表明，仅当最初形成硫化钠或硫化钙时，可溶性金属化合物才能转化为不溶性金属硫化物。发现在403k的粉煤灰中添加硫和氢氧化钠导致重金属的硫化。同样，在523K处添加硫和氢氧化钙会导致重金属的硫化。通过提出的固定方法对处理过的粉煤灰的渗滤液测试结果表明，在粉煤灰中浸出重金属是可抑制的。