本文選題：濕法磷酸 + 脫氟��； 參考：《武漢工程大學(xué)》2015年碩士論文

【摘要】：氟化鉀是一種重要的無(wú)機(jī)氟化工產(chǎn)品,廣泛應(yīng)用于醫(yī)藥、防腐和玻璃雕刻等方面,特別是在含氟有機(jī)產(chǎn)品合成方面有著重要作用。隨著傳統(tǒng)氟資源螢石的短缺,利用濕法磷酸生成產(chǎn)中的氟資源生產(chǎn)氟化鉀有著重要意義。本文的主要目的是利用濕法磷酸液相中的氟資源,脫氟并制備氟化鉀。本文對(duì)脫氟和氟化鉀制備工藝進(jìn)行了研究,并對(duì)相關(guān)機(jī)理進(jìn)行了研究分析。實(shí)驗(yàn)分別研究了以硫酸鉀和氯化鉀為脫氟劑的濕法磷酸脫氟工藝。硫酸鉀的最佳脫氟工藝條件為:硫酸鉀用量是理論用量的1.2倍,反應(yīng)時(shí)間為1h,反應(yīng)溫度為30℃。氯化鉀的最佳脫氟工藝為:氯化鉀用量是理論用量的1倍,反應(yīng)時(shí)間為1h,反應(yīng)溫度為30℃。反應(yīng)都在攪拌均勻情況下進(jìn)行,攪拌速度為30rpm。同時(shí),實(shí)驗(yàn)還研究了氟硅酸的脫氟過(guò)程,最佳工藝條件如下:反應(yīng)溫度為30℃下,硫酸鉀和氯化鉀用量是理論用量的1倍,反應(yīng)時(shí)間為1h,此時(shí)氟硅酸收率為92%左右。實(shí)驗(yàn)對(duì)脫氟過(guò)程進(jìn)行了研究,脫氟助劑為二氧化硅,實(shí)驗(yàn)發(fā)現(xiàn)具有反應(yīng)活性的二氧化硅才具有良好的脫氟效果,二氧化硅和濕法磷酸中氫氟酸反應(yīng)是連續(xù)反應(yīng),先生成四氟化硅再生成氟硅酸;實(shí)驗(yàn)還對(duì)硫酸鉀回收濕法磷酸和氟硅酸溶液中的氟硅酸過(guò)程進(jìn)行了熱力學(xué)分析,反應(yīng)產(chǎn)物氟硅酸鉀收率主要受化學(xué)反應(yīng)平衡和氟硅酸鉀沉淀平衡共同影響,但由于反應(yīng)平衡進(jìn)行的限度很大,可以認(rèn)為是完全反應(yīng),氟硅酸鉀收率主要由氟硅酸鉀沉淀平衡控制。以脫氟產(chǎn)物氟硅酸鉀和氫氧化鉀為原料制備氟化鉀時(shí),最佳工藝條件為:氫氧化鉀用量是理論用量的1.07倍,反應(yīng)時(shí)間為1h,反應(yīng)溫度為80℃,氫氧化鉀濃度為30%~40%,氟硅酸鉀的水固比為1:3,濾餅水洗次數(shù)為3次,氟硅酸反調(diào)pH終點(diǎn)為7.7~8,此時(shí)氟化鉀的收率為90%左右.實(shí)驗(yàn)對(duì)氟化鉀的品質(zhì)控制進(jìn)行了研究,反調(diào)pH過(guò)高時(shí),游離堿含量過(guò)高,pH過(guò)低時(shí),游離酸過(guò)高,pH為7~8時(shí),產(chǎn)品二氧化硅含量較低。制備氟化鉀的反應(yīng)r mH??〈0,為放熱反應(yīng),Δr Gm㩳0,反應(yīng)常溫下能自發(fā)進(jìn)行,反應(yīng)存在明顯誘導(dǎo)時(shí)間,高溫有利于縮短誘導(dǎo)時(shí)間。
[Abstract]:Potassium fluoride is an important inorganic fluorine chemical product, which is widely used in medicine, anticorrosion and glass engraving, especially in the synthesis of fluorine-containing organic products. With the shortage of fluorite in traditional fluorine resources, it is of great significance to produce potassium fluoride by using wet phosphoric acid to produce potassium fluoride. The main purpose of this paper is to defluorinate and prepare potassium fluoride by using fluorine resources in wet phosphoric acid liquid phase. In this paper, defluorination and preparation of potassium fluoride were studied, and the related mechanism was analyzed. The defluorination process of wet phosphoric acid with potassium sulfate and potassium chloride as defluorination agent was studied. The optimum defluorination conditions of potassium sulfate are as follows: the amount of potassium sulfate is 1.2 times of the theoretical dosage, the reaction time is 1 h, and the reaction temperature is 30 鈩，

本文編號(hào)：1900317