【摘要】：近年來(lái)溫室效應(yīng)一直是人們議論的熱點(diǎn),二氧化碳減排問(wèn)題更是得到國(guó)際社會(huì)的廣泛關(guān)注。二氧化碳的大量排放不僅給經(jīng)濟(jì)發(fā)展帶來(lái)阻礙,也給人們的生產(chǎn)生活帶來(lái)困擾。為緩解溫室效應(yīng),二氧化碳的捕集與儲(chǔ)存(CCS)得到快速發(fā)展,其中的礦物儲(chǔ)存二氧化碳被寄予了厚望。由于直接用礦物儲(chǔ)存二氧化碳會(huì)涉及到礦物的開采和制備,成本和能源投入較大,而堿性工業(yè)廢物具有來(lái)源廣,價(jià)格低廉等優(yōu)勢(shì),是礦物最適合的替代品。作為堿性工業(yè)廢物之一,鉻渣的堆積存放和不及時(shí)處置對(duì)周邊環(huán)境和人們生活造成巨大困擾,尤其是鉻渣中的六價(jià)鉻遷移能力強(qiáng)、水溶性大,且具致癌性,危害極大。本文將鉻渣處理和二氧化碳減排問(wèn)題進(jìn)行有機(jī)的結(jié)合,利用二者自身的特有性質(zhì),以達(dá)到共同處理的目的。本文首先組建了鉻渣儲(chǔ)存二氧化碳裝置,考察了溫度、水渣比、反應(yīng)壓力和時(shí)間等因素對(duì)鉻渣儲(chǔ)存二氧化碳的影響,并利用X射線衍射圖譜分析(XRD)和熱重分析(TG)等技術(shù),探究了鉻渣的二氧化碳儲(chǔ)存量和終產(chǎn)物。其次,利用二氧化碳?xì)怏w的酸性性質(zhì),研究了其和水形成的酸性淋溶劑對(duì)鉻渣中六價(jià)鉻的淋溶能力,并考察了在淋溶過(guò)程中鉻渣對(duì)二氧化碳的固定效果。在鉻渣儲(chǔ)存二氧化碳實(shí)驗(yàn)過(guò)程中,最佳的反應(yīng)條件是溫度為120℃,水渣比為0.2,反應(yīng)壓力和時(shí)間分別為1MPa和2小時(shí)。此條件下,CaCO3和MgCO3·3H2O是鉻渣的二氧化碳儲(chǔ)存終產(chǎn)物;鉻渣中CaO和MgO的碳酸化程度分別為38.3%和1.1%。鉻渣儲(chǔ)存二氧化碳的能力為102.6g/kg。二氧化碳對(duì)鉻渣中六價(jià)鉻淋溶實(shí)驗(yàn)表明,二氧化碳能通過(guò)降低淋溶液pH的途徑促進(jìn)鉻渣中六價(jià)鉻的淋溶;進(jìn)一步研究發(fā)現(xiàn)較高的二氧化碳濃度和較小的鉻渣粒徑,更有利于鉻渣中六價(jià)鉻的淋溶和鉻渣對(duì)二氧化碳的儲(chǔ)存;純二氧化碳和水對(duì)鉻渣(380μm)的淋溶實(shí)驗(yàn)中,六價(jià)鉻淋溶量為2.6mg/g,二氧化碳的儲(chǔ)存量為89.1mg/g。對(duì)淋溶前后鉻渣進(jìn)行分析,發(fā)現(xiàn)淋溶后的鉻渣中有碳酸鈣生成,鉻渣碳酸化程度達(dá)到18.5%。由此可見(jiàn),鉻渣和二氧化碳的結(jié)合可以實(shí)現(xiàn)以廢治廢。鉻渣通過(guò)礦物碳酸化原理能實(shí)現(xiàn)二氧化碳的儲(chǔ)存;此外,二氧化碳能用作淋溶劑,促進(jìn)鉻渣中六價(jià)鉻的淋溶,同時(shí)在淋溶過(guò)程中實(shí)現(xiàn)碳儲(chǔ)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，

本文編號(hào)：2333395