本文關(guān)鍵詞： 海水淡化 濃海水 電滲析 海鹽 水鹽體系　出處：《天津大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：海水作為水資源的重要組成部分,其有效利用是解決我國水資源短缺的重要途徑之一。海水淡化技術(shù)的成熟,催生了海水淡化項目建設(shè),在一定程度上緩解了沿海地區(qū)尤其是經(jīng)濟發(fā)展迅速的沿海城市用水緊張問題。在大型海水淡化工程項目建設(shè)時,其副產(chǎn)的高濃度海水將對封閉海域的生態(tài)環(huán)境產(chǎn)生一定的影響,根據(jù)循環(huán)經(jīng)濟發(fā)展規(guī)劃及海洋生態(tài)環(huán)境保護要求,濃海水高效利用技術(shù)研究將成為海水資源開發(fā)利用的先決條件。電滲析作為高效膜分離技術(shù)是選擇性分離電解質(zhì)離子的有效方法之一,在國外已被廣泛應(yīng)用。在國內(nèi)制鹽行業(yè)中應(yīng)用電滲析技術(shù),最近幾年取得了一定的研究進展,但至今未見工業(yè)化應(yīng)用報道。本文以某電廠排出的5.4?Be'濃海水為原料,研究濃海水的凈化、電滲析、蒸發(fā)濃縮、析鹽、析鉀、制取低鈉鹽等工藝及其工業(yè)化的可行性。發(fā)現(xiàn),濃海水凈化后通過電滲析膜組件,Na+、K+、Cl-等一價離子選擇透過性較好,控制脫鹽率80%時,所得濃鹽水鹽度≥20%,其中:NaCl≥210g/l、KCl≥6g/l;濃水量為原料量的15.5%,濃縮回收率:NaCl≥80%、KCl≥85%,電滲析能耗≤40KW·h/m3。濃鹽水在蒸發(fā)結(jié)晶過程中:108.5℃時析出精制鹽,回收率60%;濃縮液蒸發(fā)終止115℃,氯化鈉結(jié)晶析出率≥97%,精制鹽經(jīng)脫水干燥后NaCl≥99.1%;冷卻結(jié)晶溫度25℃氯化鉀結(jié)晶析出率≥60%,精制氯化鉀產(chǎn)品中KCl≥99.1%;低溫蒸發(fā)真空度0.098MPa,溶液蒸發(fā)終止溫度42℃,低鈉鹽產(chǎn)品NaCl≥68%、KCl≥30%、雜質(zhì)鹽含量1%;蒸發(fā)結(jié)晶母液NaCl≤2%、KCl≤3.5%,濃海水提取率:NaCl≥80%、KCl≥85%,高于鹽田制鹽海水利用率,精制鹽產(chǎn)品折合市場價成本約350元/噸,研究的海水淡化濃海水電滲析制鹽工藝具有工業(yè)化生產(chǎn)應(yīng)用價值。
[Abstract]:As an important part of water resources, the effective utilization of seawater is one of the important ways to solve the shortage of water resources in China. The maturity of seawater desalination technology has given birth to the construction of desalination projects. To some extent, the shortage of water in coastal areas, especially in coastal cities with rapid economic development, has been alleviated. In the construction of large-scale desalination projects, the high concentration of seawater by-products will have a certain impact on the ecological environment of the enclosed sea areas. According to the development plan of circular economy and the requirements of marine ecological environment protection, The study on high efficiency utilization of concentrated seawater will be a prerequisite for the exploitation and utilization of seawater resources. Electrodialysis is one of the effective methods for selective separation of electrolyte ions as a high efficiency membrane separation technique. The application of electrodialysis technology in the domestic salt industry has made some progress in recent years, but no industrial application report has been seen so far. In this paper, the discharge of a power plant 5.4? The process of purification, electrodialysis, evaporation and concentration, salt evolution, potassium evolution, preparation of low sodium salt and the feasibility of industrialization of the concentrated sea water were studied, such as the purification of concentrated sea water, electrodialysis, evaporation and concentration, salt evolution, potassium evolution and the feasibility of industrialization. When the desalination rate is controlled by 80%, the selective permeability of ion such as Na ~ (+) K ~ (+) Cl ~ (-) is better through electrodialysis membrane assembly after purification of concentrated seawater. The salinity of concentrated brine is 鈮，

本文編號：1494089