本文選題：硫酸鉀　切入點(diǎn)：轉(zhuǎn)化法　出處：《寧夏大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：火電廠、化工廠煙氣脫硫的主要副產(chǎn)物脫硫石膏(CaSO_4O_2H_2O)及PVC企業(yè)脫硝副產(chǎn)物芒硝(Na_2SO_4·10H_2O)已成為我國(guó)硫酸鹽型主要固體廢棄物,不僅占用土地,而且污染環(huán)境。而我國(guó)鉀、硫資源極度缺乏,尤其是硫酸鉀,長(zhǎng)期依賴于俄羅斯、德國(guó)等國(guó)進(jìn)口。若能以西北鹽湖低品質(zhì)氯化鉀及工業(yè)硫酸鹽型固體廢棄物脫硫石膏及芒硝轉(zhuǎn)化生產(chǎn)高附加值的硫酸鉀,無(wú)疑是對(duì)西北無(wú)機(jī)鹽資源高值化、硫酸鹽型固體廢棄物資源化利用提供新途徑。本文以某PVC企業(yè)的芒硝廢渣和寧夏某廠的脫硫石膏制備碳酸鈣晶須的硫酸銨母液為硫酸根來(lái)源,以青海鹽湖低品質(zhì)氯化鉀為鉀源,采用轉(zhuǎn)化法制備硫酸鉀。首先對(duì)相關(guān)體系相平衡數(shù)據(jù)進(jìn)行研究,分別獲得了 298.15K、333.15K,K~+,NH_4~+//Cl~-,SO_4~(2-)-H_2O、K~+,NH_4~+//Cl~-,SO_4~(2-)-(CH_2OH)_2-H_2O 體系和 328.15 K 體系 Na+,K~+//Cl~-,SO_4~(2-)-(CH_2OH)_2-H_2O 及其子體系 Na+,K~+//SO_4~(2-)-(CH_2OH)_2-H_2O的固液相平衡數(shù)據(jù)及物化性質(zhì)(nD,η,ρ,pH),構(gòu)建相圖,劃分結(jié)晶區(qū),用以指導(dǎo)和優(yōu)化轉(zhuǎn)化法生產(chǎn)硫酸鉀工藝。其次利用相圖數(shù)據(jù)對(duì)芒硝轉(zhuǎn)化法生產(chǎn)硫酸鉀的過(guò)程進(jìn)行了理論計(jì)算及工藝分析。結(jié)果表明采用間接轉(zhuǎn)化法對(duì)母液進(jìn)行循環(huán)回收能提高硫酸鉀收率,同時(shí)對(duì)硫酸銨轉(zhuǎn)化法生產(chǎn)硫酸鉀的工藝也進(jìn)行了相圖計(jì)算。此外,基于相圖分析,考察了氯化鉀與芒硝廢渣轉(zhuǎn)化法生產(chǎn)硫酸鉀的工藝條件,得到最佳工藝條件為反應(yīng)溫度25℃、反應(yīng)時(shí)間100min、配料比(芒硝與氯化鉀的質(zhì)量比)為1.26:1、攪拌強(qiáng)度200rpm,在最優(yōu)工藝條件下,芒硝廢渣轉(zhuǎn)化法生產(chǎn)硫酸鉀兩步轉(zhuǎn)化K_2O收率為89%,產(chǎn)品中K20含量為50.42%,氯離子含量1.8%,硫酸鉀質(zhì)量達(dá)到國(guó)家鉀肥生產(chǎn)農(nóng)用一等品標(biāo)準(zhǔn)。此外,以脫硫石膏制備碳酸鈣晶須的硫酸銨母液制備硫酸鉀的最優(yōu)工藝條件為:硫酸銨初始濃度34w%、配料比(n(NH4)2SO4:nKCl)為0.5、攪拌速率200rpm、反應(yīng)時(shí)間120min、反應(yīng)溫度40℃。驗(yàn)證實(shí)驗(yàn)得到K_2O收率64%,此時(shí)產(chǎn)品K_2O%50%,w(Cl~-)0.15%,w(NH_4~+)0.3%,產(chǎn)品硫酸鉀符合農(nóng)用優(yōu)等品的標(biāo)準(zhǔn)。由于K~+,NH_4~+水鹽體系存在鉀-銨基固溶體,且相圖中該固溶體結(jié)晶區(qū)面積約占80%以上,因此本文對(duì)鉀-銨基固溶體的分離進(jìn)行了理論分析。提出多級(jí)逆流結(jié)晶分離鉀-銨基固溶體的數(shù)學(xué)模型,采用不同的蒸發(fā)策略進(jìn)行模擬具體過(guò)程的變量。鉀-銨基固溶體的分離,不僅能提高硫酸鉀產(chǎn)率及品質(zhì),對(duì)水鹽體系固溶體中有價(jià)元素的高效可控分離提供借鑒。本文的研究成果對(duì)脫硫石膏廢渣制備碳酸鈣晶須產(chǎn)生的高濃度硫酸銨母液、脫硫石膏、芒硝的資源化利用找到了有效的處理方法,具有良好的經(jīng)濟(jì)社會(huì)效益與應(yīng)用前景。
[Abstract]:Thermal power plant, the main by-product of flue gas desulphurization in chemical plant, gypsum, CaSOs 4O 2H _ 2O) and the by-product of PVC enterprise denitrification, Na2SO4 路10H _ 2O), have become the main solid waste of sulphate type in our country, which not only occupy the land, but also pollute the environment. Sulfur resources are extremely scarce, especially potassium sulfate, which has been imported by Russia, Germany and other countries for a long time. If we can convert desulphurized gypsum and mirabilite, a solid waste of industrial sulphate, to produce potassium sulfate with high added value, we can use low quality potassium chloride in the Northwest Salt Lake and industrial sulphate solid waste to produce potassium sulfate. It is undoubtedly a new way for the high value of inorganic salt resources in Northwest China and the utilization of sulphate solid wastes. In this paper, the source of sulfate is the ammonium sulfate mother liquor from the waste residue of a PVC enterprise and the desulphurized gypsum from a certain Ningxia plant to produce calcium carbonate whisker. Using low quality potassium chloride as potassium source in Qinghai salt lake, potassium sulfate was prepared by transformation method. Firstly, the phase equilibrium data of related systems were studied. We have obtained respectively 298.15K / 333.15K / K / K / NH _ 4- / -Cl ~ + -so _ 4H _ 2O / K ~ / K ~ / K ~ / K ~ + NH _ 4- /-/ C / Cl-so _ 4 ~ / C ~ / C ~ / C ~ (-1) -C _ 2O -so _ 4O _ 2-H _ 2O system, respectively. We have obtained the solid-state equilibrium data and the physicochemical properties of nDX, 畏, 蟻, pH, p ~ (-1), p ~ (-1) -so _ 2O _ 2-H _ 2O _ 2-H2O, and its subsystem Na _ K- / / S _ 2O _ 2-H _ 2O _ 2-H2O _ 2-H2O _ 2-H2OH _ 2O. We have constructed a phase diagram and a region of crystallization, and we have also obtained the structure of the structure of the phase diagram, the structure of the phase diagram, the structure of the structure, the structure of the phase diagram, the structure of the phase diagram, the structure of the phase diagram, the structure of the phase diagram, the structure of the structure. It is used to guide and optimize the process of producing potassium sulfate by transformation method. Secondly, the theoretical calculation and process analysis of potassium sulfate production by using phase diagram data are carried out. The results show that indirect transformation method is used to follow through on mother liquor. Cyclic recovery can improve the yield of potassium sulfate. At the same time, the process of producing potassium sulfate by ammonium sulfate conversion was also calculated. In addition, based on the phase diagram analysis, the technological conditions of producing potassium sulfate by transformation of potassium chloride and waste residue of mirabilite were investigated. The optimum process conditions were obtained as follows: reaction temperature 25 鈩，

本文編號(hào)：1643478