二氧化碳的铬渣封存及其对六价铬淋溶
发布时间：2018-11-15 13:09
【摘要】：近年来温室效应一直是人们议论的热点,二氧化碳减排问题更是得到国际社会的广泛关注。二氧化碳的大量排放不仅给经济发展带来阻碍,也给人们的生产生活带来困扰。为缓解温室效应,二氧化碳的捕集与储存(CCS)得到快速发展,其中的矿物储存二氧化碳被寄予了厚望。由于直接用矿物储存二氧化碳会涉及到矿物的开采和制备,成本和能源投入较大,而碱性工业废物具有来源广,价格低廉等优势,是矿物最适合的替代品。作为碱性工业废物之一,铬渣的堆积存放和不及时处置对周边环境和人们生活造成巨大困扰,尤其是铬渣中的六价铬迁移能力强、水溶性大,且具致癌性,危害极大。本文将铬渣处理和二氧化碳减排问题进行有机的结合,利用二者自身的特有性质,以达到共同处理的目的。本文首先组建了铬渣储存二氧化碳装置,考察了温度、水渣比、反应压力和时间等因素对铬渣储存二氧化碳的影响,并利用X射线衍射图谱分析(XRD)和热重分析(TG)等技术,探究了铬渣的二氧化碳储存量和终产物。其次,利用二氧化碳气体的酸性性质,研究了其和水形成的酸性淋溶剂对铬渣中六价铬的淋溶能力,并考察了在淋溶过程中铬渣对二氧化碳的固定效果。在铬渣储存二氧化碳实验过程中,最佳的反应条件是温度为120℃,水渣比为0.2,反应压力和时间分别为1MPa和2小时。此条件下,CaCO3和MgCO3·3H2O是铬渣的二氧化碳储存终产物;铬渣中CaO和MgO的碳酸化程度分别为38.3%和1.1%。铬渣储存二氧化碳的能力为102.6g/kg。二氧化碳对铬渣中六价铬淋溶实验表明,二氧化碳能通过降低淋溶液pH的途径促进铬渣中六价铬的淋溶;进一步研究发现较高的二氧化碳浓度和较小的铬渣粒径,更有利于铬渣中六价铬的淋溶和铬渣对二氧化碳的储存;纯二氧化碳和水对铬渣(380μm)的淋溶实验中,六价铬淋溶量为2.6mg/g,二氧化碳的储存量为89.1mg/g。对淋溶前后铬渣进行分析,发现淋溶后的铬渣中有碳酸钙生成,铬渣碳酸化程度达到18.5%。由此可见,铬渣和二氧化碳的结合可以实现以废治废。铬渣通过矿物碳酸化原理能实现二氧化碳的储存;此外,二氧化碳能用作淋溶剂,促进铬渣中六价铬的淋溶,同时在淋溶过程中实现碳储存。
[Abstract]:In recent years, Greenhouse Effect has been a hot topic, and carbon dioxide emission reduction has been paid more and more attention by the international community. The massive emission of carbon dioxide not only hinders the development of economy, but also puzzles people's production and life. In order to alleviate Greenhouse Effect, carbon dioxide capture and storage (CCS) has developed rapidly, and the mineral carbon dioxide storage is expected. The direct storage of carbon dioxide by minerals will involve the mining and preparation of minerals, and the cost and energy input will be large. However, alkaline industrial waste is the most suitable substitute for minerals because of its advantages of wide sources and low price. As one of the basic industrial wastes, the accumulation and storage of chromium slag and its untimely disposal have caused great troubles to the surrounding environment and people's lives. Especially, the hexavalent chromium in chromium slag has strong migration ability, high water solubility, carcinogenicity and great harm. In this paper, chromium slag treatment and carbon dioxide emission reduction are organically combined, and their unique properties are used to achieve the purpose of joint treatment. In this paper, a carbon dioxide storage device for chromium slag was first built, and the effects of temperature, water / slag ratio, reaction pressure and time on carbon dioxide storage by chromium slag were investigated. The carbon dioxide storage and final product of chromium residue were investigated by using X-ray diffraction pattern analysis of (XRD) and thermogravimetric analysis of (TG). Secondly, using the acidic properties of carbon dioxide gas, the leaching ability of hexavalent chromium in chromium slag was studied by acid leaching solvent formed with water, and the immobilization effect of chromium residue on carbon dioxide during leaching process was investigated. In the experiment of storing carbon dioxide from chromium slag, the optimum reaction conditions are as follows: temperature is 120 鈩，
本文编号：2333395
[Abstract]:In recent years, Greenhouse Effect has been a hot topic, and carbon dioxide emission reduction has been paid more and more attention by the international community. The massive emission of carbon dioxide not only hinders the development of economy, but also puzzles people's production and life. In order to alleviate Greenhouse Effect, carbon dioxide capture and storage (CCS) has developed rapidly, and the mineral carbon dioxide storage is expected. The direct storage of carbon dioxide by minerals will involve the mining and preparation of minerals, and the cost and energy input will be large. However, alkaline industrial waste is the most suitable substitute for minerals because of its advantages of wide sources and low price. As one of the basic industrial wastes, the accumulation and storage of chromium slag and its untimely disposal have caused great troubles to the surrounding environment and people's lives. Especially, the hexavalent chromium in chromium slag has strong migration ability, high water solubility, carcinogenicity and great harm. In this paper, chromium slag treatment and carbon dioxide emission reduction are organically combined, and their unique properties are used to achieve the purpose of joint treatment. In this paper, a carbon dioxide storage device for chromium slag was first built, and the effects of temperature, water / slag ratio, reaction pressure and time on carbon dioxide storage by chromium slag were investigated. The carbon dioxide storage and final product of chromium residue were investigated by using X-ray diffraction pattern analysis of (XRD) and thermogravimetric analysis of (TG). Secondly, using the acidic properties of carbon dioxide gas, the leaching ability of hexavalent chromium in chromium slag was studied by acid leaching solvent formed with water, and the immobilization effect of chromium residue on carbon dioxide during leaching process was investigated. In the experiment of storing carbon dioxide from chromium slag, the optimum reaction conditions are as follows: temperature is 120 鈩，
本文编号：2333395
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