發(fā)布時(shí)間：2018-06-08 08:09

  本文選題：純堿 + 廢鹽　； 參考：《北京化工大學(xué)》2016年碩士論文

【摘要】：本研究以工業(yè)廢棄氯化鈉與碳酸氫銨作為原料,利用水溶液體系中發(fā)生的復(fù)分解反應(yīng)原理,制備了純堿并聯(lián)產(chǎn)氯化銨,其中生產(chǎn)純堿的生產(chǎn)單元為本工藝的第一單元,回收來自第一單元母液中的氯化銨為第二單元。采用正交試驗(yàn)法,通過實(shí)驗(yàn)系統(tǒng)研究了第一單元中反應(yīng)溫度、反應(yīng)時(shí)間及反應(yīng)物料比對單次反應(yīng)生成的中間產(chǎn)物碳酸氫鈉收率的影響,以獲得較優(yōu)的工藝條件；選擇了鹽析劑并確定其用量以進(jìn)一步回收第一單元母液中碳酸氫鈉,鹽析劑經(jīng)處理后循環(huán)利用；采用濃縮結(jié)晶方法,研究了第二單元回收氯化銨的工藝條件；在此基礎(chǔ)上,完成了年處理7.3萬噸工業(yè)廢鹽制備純堿聯(lián)產(chǎn)氯化銨的工藝物料衡算,并進(jìn)行了關(guān)鍵設(shè)備的選型。首先,根據(jù)水鹽體系四元交互相圖確定了第一單元的工藝條件范圍,研究了反應(yīng)溫度和時(shí)間對中間產(chǎn)物碳酸氫鈉收率的影響,實(shí)驗(yàn)發(fā)現(xiàn)適當(dāng)提高反應(yīng)溫度并延長反應(yīng)時(shí)間有助于提高碳酸氫鈉收率,同時(shí)適當(dāng)調(diào)整反應(yīng)物料比也可提高碳酸氫鈉收率；進(jìn)一步的正交試驗(yàn)結(jié)果表明,在優(yōu)化的工藝條件下,即反應(yīng)溫度為35℃,廢鹽與碳酸氫銨的物質(zhì)量比為1.05,反應(yīng)時(shí)間為120min時(shí),第一單元單次中間產(chǎn)物碳酸氫鈉收率最高,達(dá)到75%,經(jīng)400℃煅燒后得到純堿純度超過98%,符合國家標(biāo)準(zhǔn)。為了提高碳酸氫鈉的收率,本研究利用反溶劑原理,選用三種有機(jī)鹽析劑對母液進(jìn)行處理。實(shí)驗(yàn)結(jié)果顯示,選用鹽析劑C并且用量為廢鹽物質(zhì)量的1.5倍時(shí),可從母液中再度析出的碳酸氫鈉量達(dá)到單次反應(yīng)產(chǎn)量10%以上,第一單元單循環(huán)可制備碳酸鈉收率超過88%。在第二單元,采用中和反應(yīng)原理,利用兩種酸對來自第一單元的鹽析后的澄清母液進(jìn)行處理后回收氯化銨,其中濃鹽酸處理所得氯化銨收率最高為86.42%,副產(chǎn)物氮含量符合國家標(biāo)準(zhǔn)。利用工藝流程模擬軟件Aspen對年處理量7.3萬噸廢氯化鈉生產(chǎn)純堿并聯(lián)產(chǎn)氯化銨工藝流程進(jìn)行了物料衡算,完成了PFD圖與PID圖,并對關(guān)鍵設(shè)備進(jìn)行了初步計(jì)算和選型。
[Abstract]:In this study, the industrial waste sodium chloride and ammonium bicarbonate were used as raw materials, and the principle of double decomposition reaction in aqueous solution was used to prepare soda and co-produce ammonium chloride, in which the unit of producing soda was the first unit of this process. The recovery of ammonium chloride from the first unit mother liquor is the second unit. The effects of reaction temperature, reaction time and reactant ratio on the yield of sodium bicarbonate in the first unit were studied by orthogonal test. The sodium bicarbonate from the first unit mother liquor was further recovered by selecting salting-out agent and its dosage was determined. The salting-out agent was reused after treatment. The technological conditions for recovering ammonium chloride in the second unit were studied by means of concentrated crystallization. The material balance of 73000 tons of industrial waste salt per year for the production of ammonium chloride from soda is completed, and the selection of key equipment is carried out. Firstly, according to the quaternary phase diagram of water-salt system, the technological conditions of the first unit were determined, and the effects of reaction temperature and time on the yield of sodium bicarbonate, the intermediate product, were studied. It is found that increasing the reaction temperature and prolonging the reaction time can improve the yield of sodium bicarbonate and adjust the ratio of reactant to material to increase the yield of sodium bicarbonate. When the reaction temperature is 35 鈩，

本文編號：1995273