本文選題：碘 + 溶劑萃取�。� 參考：《哈爾濱工業(yè)大學(xué)》2014年碩士論文

【摘要】：海洋被稱為自然界的“碘庫”，以海水或海藻為原料提取碘已成為該領(lǐng)域的趨勢。本文以海帶浸取液為原料，分別采用溶劑萃取法與活性炭吸附法從中提取碘。在溶劑萃取法中以氧化率、萃取率和分配比為考察指標，優(yōu)化了萃取工藝條件；在活性炭吸附法中，以吸附率為考察指標，優(yōu)化了吸附工藝條件。采用恒界面池法，探究了溶劑萃取碘過程的傳質(zhì)動力學(xué)。 試驗過程中，采用氧化還原滴定法測定碘離子濃度，步驟參照國家標準；采用紫外分光光度法繪制測定碘濃度的標準曲線，其試驗條件為：5mL碘酸鉀標準溶液中加入1.0mol/L硫酸溶液2mL，10g/L碘化鉀溶液3mL，5g/L淀粉溶液5滴，顯色時間10min。 通過單因素試驗和正交試驗優(yōu)化的萃取工藝條件為：原料液酸化至pH1.5，加入亞硝酸鈉0.01g/20mL，，相比1:3，溫度55℃，轉(zhuǎn)速500r/min，反應(yīng)25min，七級逆流萃取后萃取率達到98.7%，試驗得出的萃取級數(shù)與通過McGabe-Thiele圖解法得出的理論逆流萃取級數(shù)一致。反萃取的最優(yōu)工藝條件為：溫度35℃，攪拌速率500r/min，反萃取時間8min。 活性炭吸附試驗的最優(yōu)工藝條件為：活性炭用量0.14g/100mL，攪拌速度600r/min，吸附溫度25℃，吸附50min。通過吸附等溫試驗，得出溫度升高，對吸附過程不利，與單因素試驗得出的的結(jié)論基本一致。解吸的最優(yōu)工藝條件為：溫度30℃，攪拌速度500r/min，解吸160min。 對萃取反應(yīng)進行初步熱力學(xué)研究得：反應(yīng)焓變?yōu)?1.89kJ/mol，反應(yīng)熵變?yōu)?1.38J/(mol·K)，反應(yīng)自由能小于0，該萃取碘的反應(yīng)可自發(fā)進行，升高溫度有利于萃取。 采用恒界面池法研究了原料液起始濃度、攪拌強度、界面積、溫度對萃取速率和傳質(zhì)過程的影響，得出萃取碘的過程屬于擴散控制模式，萃取碘的速率方程為：R0.0001I2 2，萃取過程活化能2.19kJ/mol，得出了轉(zhuǎn)速與傳質(zhì)系數(shù)及溫度與傳質(zhì)系數(shù)的關(guān)系。
[Abstract]:The ocean is called the "iodine bank" in nature. It has become a trend in this field to extract iodine from sea water or seaweed. Iodine was extracted from kelp leaching solution by solvent extraction and activated carbon adsorption respectively. In the solvent extraction, the oxidation rate, the extraction rate and the distribution ratio were taken as the indexes to optimize the extraction process conditions, and in the activated carbon adsorption method, the adsorption rate was taken as the inspection index, and the adsorption process conditions were optimized. The mass transfer kinetics of solvent extraction of iodine was investigated by means of constant interface cell method. During the experiment, the iodine ion concentration was determined by oxidation-reduction titration, and the standard curve of iodine concentration was drawn by ultraviolet spectrophotometry. The experimental conditions were as follows: adding 2 mL 1.0mol/L sulfuric acid solution 2 mL 10 g / L potassium iodide solution into 1: 5 mL standard solution of potassium iodate, 3 mL Ki 5 g / L starch solution 5 drops, color reaction time 10 min. The extraction conditions optimized by single factor experiment and orthogonal test are as follows: acidification of raw liquid to pH 1.5, addition of sodium nitrite 0.01g / 20mL, compared with 1: 3, temperature 55 鈩

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