摘要
铬渣因所含Cr( )具有强氧化性而会对环境造成严重污染。本文采用自养煤矸石砖焙烧技术对铬渣进行无害化治理,对不同铬渣掺量的铬渣-煤矸石砖,进行铬的浸出毒性分析。通过试验得出,除铬渣掺量为15 %的砖中六价铬浸出浓度超标外,其余铬的浸出浓度均小于国标规定,铬的解毒率都在95 %以上。此技术对Cr的还原解毒为,在高温熔融条件下,煤矸石中的碳及随后产生的CO、H2 、CH4 等还原性物质与Cr( )化合物发生反应。铬渣、煤矸石及砖的X-粉晶衍射物相分析表明,砖中Cr( )被还原为Cr( )后,以类质同相方式进入辉石、尖晶石、铝硅酸盐等稳定物相,得以固化解毒。因此,还原后Cr的存在形式稳定,可以经受恶劣自然环境而不会重新溶出和造成二次污染,作为建材。
Chromium residue is a hazardous solid waste with strong oxidation and it can cause heavy contamination to our surroundings. We adopt technique of coal gangue brick to dispose chromium residue and the leached Cr concentration and phase in sintered bricks with five various weight ratios of chromium residue to coal gangue. The results show that the percentage of Cr(Ⅵ) deoxidized to Cr(Ⅲ) in bricks with proper ratio of chromium residue to coal gangue can reach above 95% and the leached Cr concentration is much less than corresponding standard of state. All of above show that compounds of Cr(Ⅵ) are deoxidized by carbon and CO, H_2, CH_4 etc. on the condition of high temperature during sintering. X-powder diffraction shows that in bricks, there are phases such as picrite, spinelle and aluminium silicate which increases the stabilization of Cr(Ⅵ) and this form of Cr(Ⅵ) are not easily leached. So the existing forms of Cr are steady and can stand adverse environmental conditions and not dissolving again. So the brick can be used safely without worries.
出处
《安全与环境学报》
CAS
CSCD
2005年第2期11-13,共3页
Journal of Safety and Environment
基金
山东省教育厅科技发展项目 (J0 2 C0 8)
青岛市科技局科技发展项目 (0 3 -0 2 -NS-8)
关键词
环境工程
铬渣
煤矸石
浸出毒性
物相
environmental engineering
chromium residue
coal gangue
the leached Cr concentration
phase
