Department of Civil Engineering, Indian Institute of Technology, Kanpur 208016, India.
J Hazard Mater. 2011 Jan 30;185(2-3):662-8. doi: 10.1016/j.jhazmat.2010.09.069. Epub 2010 Sep 29.
The disposal of red mud, a solid waste generated during the extraction of alumina from bauxite, is one of the major problems faced by the aluminum industry. Proper disposal followed by its utilization, for example as bricks, can provide a satisfactory solution to this problem. Pollution potential of red mud and its finished product, due to metals leaching out from them under certain environmental conditions, need to be studied. Sintering of red mud was performed in a resistance type vertical tube furnace to simulate the brick-making conditions in lab-scale. Leachability of metals in red mud and the sintered product was evaluated by performing sequential extraction experiments on both. The metals studied were the 'macro metals' iron and aluminum and the 'trace metals' copper and chromium. The total extractabilities of all the metals estimated by the microwave digestion of red mud samples decreased due to sintering. The leachability in sequential extraction of the macro metals iron and aluminum, on the other hand, increased due to sintering in all phases of sequential extraction. However, the effect of sintering on the leachability of the trace metals by sequential extraction was different for copper and chromium in different fractions of sequential extraction.
赤泥是从铝土矿中提取氧化铝时产生的一种固体废物，其处理是铝工业面临的主要问题之一。对其进行适当的处理和利用，例如制成砖块，可以为解决这一问题提供满意的方案。需要研究赤泥及其成品在某些环境条件下金属浸出的污染潜力。在电阻式立式管式炉中进行了赤泥烧结实验，以模拟实验室规模的制砖条件。通过对赤泥和烧结产物进行连续提取实验，评估了金属的浸出性。研究的金属包括“常量金属”铁和铝以及“微量元素”铜和铬。通过对赤泥样品进行微波消解，估计所有金属的总提取率因烧结而降低。另一方面，在连续提取的所有阶段，常量金属铁和铝的浸出率因烧结而增加。然而，烧结对连续提取中微量元素铜和铬浸出率的影响在连续提取的不同部分是不同的。
