PDF《低温焙烧法综合处理铬渣和皮革污泥的研究》

第41 卷第

6 期 中南大学学报(自然科学版) Vol.

41 No.6

2010 年12 月Journal of Central South University (Science and Technology) Dec.

2010 低温焙烧法综合处理铬渣和皮革污泥的研究 李小斌,齐天贵,周秋生,李斌,彭志宏,刘桂华,徐文彬 (中南大学 冶金科学与工程学院,湖南 长沙,410083) 摘要:采用低温焙烧法综合处理铬渣和皮革污泥,对皮革污泥的热分解特性和铬渣中六价铬的还原规律进行实 验研究.研究结果表明:在大于

400 ℃的焙烧温度下,皮革污泥分解产生的 CO、烷烃等还原性气体可将铬渣中 的六价铬还原;

焙烧温度、焙烧时间以及铬渣与皮革污泥的质量比(pm)对铬渣中六价铬的还原有重要影响,温度 越高,焙烧时间越长,则铬渣中六价铬还原越彻底,增加皮革污泥的配量有利于铬渣中六价铬的彻底还原;

在焙 烧温度大于

500 ℃,pm≤30 的条件下,焙烧处理渣中六价铬的含量小于

35 mg/kg,其毒性浸出试验浸出液中六价 铬和总铬质量浓度分别小于 0.3 mg/L 和0.5 mg/L,符合解毒铬渣直接用于生产水泥、砖块等建筑材料的要求. 关键词:铬渣;

皮革污泥;

焙烧;

解毒;

综合处理 中图分类号:X789 文献标志码:A 文章编号:1672?7207(2010)06?2103?06 Comprehensive treatment of COPR and tannery sludge by roasting process at low temperature LI Xiao-bin, QI Tian-gui, ZHOU Qiu-sheng, LI Bin, PENG Zhi-hong, LIU Gui-hua, XU Wen-bin (School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China) Abstract: The pyrolysis characteristics of tannery sludge and the reduction law of the hexavalent chromium (Cr(Ⅵ)) in chromite ore processing residue (COPR) were investigated when the two sludge were mixed and subsequently roasted at low temperature. The results show that Cr(Ⅵ) in COPR can be reduced by the reductive gases such as carbon monoxide and alkanes released from tannery sludge with the roasting temperature above

400 ℃;

roasting temperature, retention time and mass ratio (pm) of COPR to tannery sludge play a significant role in Cr(Ⅵ) reduction;

increasing roasting temperature and retention time improves the Cr(Ⅵ) reduction, and the higher dosage of tannery sludge in the mixture, the lower Cr(Ⅵ) content in the treated residue;

when the roasting temperature is above

500 ℃ and the pm is less than 30, the Cr(Ⅵ) content in the treated residue can be less than

35 mg/kg, the Cr(Ⅵ) and total Cr concentration in the toxicity characteristic leaching procedure (TCLP) leachate of the treated residue are below 0.3 mg/L and 0.5 mg/L, respectively, which is far lower than the TCLP regulatory limit for the treated COPR used as raw material for producing construction materials such as block and cement. Key words: chromite ore processing residue (COPR);

tannery sludge;

roasting process;

detoxification;

comprehensive treatment 铬渣是采用有钙焙烧法生产铬盐过程中产生的主 要废渣,它含有大量致癌的高毒性六价铬,造成严重 的环境污染[1] . 目前, 铬渣的处理方法主要是利用 Fe2+ 化合物[2?3] 、硫化物、多硫化物[4?5] 和还原细菌等将铬 渣中高毒性的六价铬还原后堆存或综合利用.在一般 的铬渣处理过程中,由于部分 Cr(Ⅵ)存在于复杂物相 收稿日期:2009?11?15;

修回日期:2010?01?28 基金项目:湖南省科技重大专项资助项目(2009FJ1009) 通信作者: 周秋生(1972?), 男, 湖南涟源人, 博士, 副教授, 从事铬盐清洁生产及铬污染治理研究;