本文選題：工業(yè)級氫氟酸 + 工業(yè)級硫酸鈉　； 參考：《昆明理工大學(xué)》2015年碩士論文

【摘要】：目前,磷肥行業(yè)副產(chǎn)的氟硅酸多用于生產(chǎn)氟硅酸鈉,氟資源利用不合理問題突出。氟化鈉作為重要的氟化鹽,由于其防齲齒效果較好用作了牙膏添加劑。牙膏級氟化鈉市場供需不平衡,供不應(yīng)求問題突出。針對存在的問題,本課題提出制備牙膏級氟化鈉的構(gòu)思,結(jié)合云天化股份有限公司生產(chǎn)的特點(diǎn),希望探索出一條綠色、環(huán)保、節(jié)能的牙膏級氟化鈉的生產(chǎn)路線。實(shí)驗(yàn)以原料純化處理→產(chǎn)品合成→產(chǎn)品洗滌為路線進(jìn)行工藝探索,通過對工藝條件的優(yōu)化,找出較為適宜的工藝條件。1.原料的純化處理主要包括氫氟酸脫硅處理和硫酸鈉脫除鐵、鎂、鈣離子兩部分。(1)原料氫氟酸中含有0.5%氟硅酸對產(chǎn)品氟化鈉的質(zhì)量有影響,需對氫氟酸進(jìn)行脫硅實(shí)驗(yàn)。實(shí)驗(yàn)以脫硅率為指標(biāo),確定了較優(yōu)的脫硅工藝條件為：碳酸鈉作為脫硅劑,在室溫(25±5℃),用量為理論量過量5%,反應(yīng)時(shí)間為30min。(2)硫酸鈉中的鐵、鎂、鈣離子等離子對產(chǎn)品質(zhì)量有一定影響。實(shí)驗(yàn)在60℃的硫酸鈉溶液中加入氫氧化鈉,并控制反應(yīng)后pH在11.5-12.0以上,反應(yīng)時(shí)間為30min,攪拌強(qiáng)度為100r/min。純化所得硫酸鈉溶液中的鈣鎂鐵含量分別降低到0.032%、0.021%、0.0042%。2.對于產(chǎn)品合成過程主要采用熱力學(xué)分析結(jié)合實(shí)驗(yàn)的方法對實(shí)驗(yàn)過程進(jìn)行探討。(1)通過對主反應(yīng)的熱力學(xué)分析探討了實(shí)驗(yàn)的可行性。通過計(jì)算確定了△rHm'0, △rSm'0、△rGm0,反應(yīng)的推動(dòng)力為溶解度差,因此反應(yīng)溫度對實(shí)驗(yàn)結(jié)果的影響較大。(2)通過分析確定了單因素實(shí)驗(yàn)的考察指標(biāo)為產(chǎn)品的產(chǎn)率和氟化鈉的純度。通過單因素實(shí)驗(yàn)與正交實(shí)驗(yàn),優(yōu)化了工藝參數(shù)：氫氟酸濃度為18mol/L,反應(yīng)溫度選擇為40℃,反應(yīng)時(shí)間在60min,陳化溫度為15℃,陳化時(shí)間為15min。在此優(yōu)化的工藝條件下,得到的粗產(chǎn)品的平均收率為98.338%,平均純度為96.578%。同時(shí)通過對粗產(chǎn)品的洗滌研究,開展了洗滌單因素實(shí)驗(yàn),確定了較優(yōu)的工藝條件為：蒸餾水用量為2 L/kg產(chǎn)品,洗滌水溫度為35～40℃。洗滌后產(chǎn)品的氟化鈉含量≥98.5%,硫酸根含量≤0.05%。通過上述工藝合成的牙膏級氟化鈉,反應(yīng)的最終收率在95%以上,產(chǎn)品就能較好的達(dá)到企業(yè)標(biāo)準(zhǔn)Q/XWJ114-2007的要求。
[Abstract]:At present, fluorosilicic acid in phosphate fertilizer industry is mostly used to produce sodium fluorosilicate. As an important fluoride salt, sodium fluoride has been used as toothpaste additive because of its good anti-dental caries effect. Toothpaste-grade sodium fluoride market supply and demand imbalance, demand is outstanding. In view of the existing problems, this paper puts forward the idea of preparing toothpaste grade sodium fluoride, combined with the characteristics of Yuntian Chemical Co., Ltd., hoping to explore a green, environmental protection, energy saving toothpaste grade sodium fluoride production route. In this experiment, the purification of raw materials and the washing of synthetic products were used as the route to explore the process. Through the optimization of the process conditions, the more suitable technological conditions were found out. The purification of raw materials mainly includes desilication of hydrofluoric acid and removal of iron from sodium sulfate. Magnesium and calcium ions in the raw material contain 0.5% fluorosilicic acid, which has an effect on the quality of sodium fluoride. The desilication experiment of hydrofluoric acid is needed. With the desilication rate as the index, the optimum desilication process conditions were determined as follows: sodium carbonate as desilication agent, iron and magnesium in sodium sulfate at room temperature of 25 鹵5 鈩，

本文編號：1899717