Environmental Chemistry Division, Advanced Materials & Processes Research Institute, (C.S.I.R.), Hoshangabad Road, Bhopal 462064, MP, India.
J Hazard Mater. 2010 Apr 15;176(1-3):1044-50. doi: 10.1016/j.jhazmat.2009.11.146. Epub 2009 Dec 4.
Red mud, an aluminium industry hazardous waste, has been reported to be an inexpensive and effective adsorbent. In the present work applicability of red mud for the sequestration of green house gases with reference to carbon dioxide has been studied. Red mud sample was separated into three different size fractions (RM I, RM II, RM III) of varying densities (1.5-2.2 g cm(-3)). Carbonation of each fraction of red mud was carried out separately at room temperature using a stainless steel reaction chamber at a fixed pressure of 3.5 bar. Effects of reaction time (0.5-12 h) and liquid to solid ratio (0.2-0.6) were studied for carbonation of red mud. Different instrumental techniques such as X-ray diffraction, FTIR and scanning electron microscope (SEM) were used to ascertain the different mineral phases before and after carbonation of each fraction of red mud. Characterization studies revealed the presence of boehmite, cancrinite, chantalite, hematite, gibbsite, anatase, rutile and quartz. Calcium bearing mineral phases (cancrinite and chantalite) were found responsible for carbonation of red mud. Maximum carbonation was observed for the fraction RM II having higher concentration of cancrinite. The carbonation capacity is evaluated to be 5.3 g of CO(2)/100 g of RM II.
赤泥是一种铝工业危险废物，已被报道为一种廉价且有效的吸附剂。本工作研究了赤泥对温室气体（以二氧化碳为例）的固定作用的适用性。将赤泥样品分离成三个不同密度（1.5-2.2 g/cm³）的粒径级分（RM I、RM II、RM III）。在室温下，使用不锈钢反应室在固定压力为 3.5 巴的条件下，分别对每个赤泥级分进行碳酸化反应。研究了碳酸化反应时间（0.5-12 h）和液固比（0.2-0.6）对赤泥碳酸化的影响。使用 X 射线衍射、傅里叶变换红外光谱和扫描电子显微镜（SEM）等不同仪器技术，在每个赤泥级分碳酸化前后确定不同的矿物相。特征研究表明存在勃姆石、方钠石、钙霞石、赤铁矿、水铝石、锐钛矿、金红石和石英。含钙矿物相（方钠石和钙霞石）被认为是赤泥碳酸化的原因。RM II 级分具有更高的方钠石浓度，观察到最大的碳酸化程度。碳酸化容量被评估为 5.3 g CO₂/100 g RM II。
