关键词: 重金属土壤;重金属铬;重金属固化;陶粒性能;固化机理

Abstract: The heavy metal pollution is an important part of soil pollution.Solidification of heavy metals using high temperature sintering is a kind of technology with high solidfication and no secondary pollution.The mechanism of the preparation of light aggregate for the solidification of heavy metals in chromium contaminated soil was studied.The heavy metal soil was simulated by adding heavy metal chromium compound in shale,and the ceramsite was sintered at 1100~1200 ℃.The results show that the mass loss of ceramsites is between 6.4% and 6.8% and the apparent density decreases with the increase of sintering temperature.The ceramic water absorption rates are between 0.2%and 1.2%.The heavy metal solidified rates are 99.8% or more.With the temperature rising, the solidification rates of heavy metals also gradually become higher.X-ray diffraction shows that the main crystal phases of the ceramsite are quartz,magnesium(aluminum,iron, chromium)spinel and eskolaite.With the increase of temperature and the holding time, the quartz in the ceramsite gradually reduces, Magnesium (aluminum,iron,chromium)spinel gradually increases.And scanning electron microscopy scan showes that heavy metal chromium is easier to enrich with magnesium,aluminum,iron.

Key words: heavy metal soil;heavy metal chromium;heavy metal solidification;ceramsite property;solidified mechanism