【摘要】：脫硫石膏是石灰石/石灰濕法煙氣脫硫技術(shù)的主要產(chǎn)物。隨著我國(guó)節(jié)能減排工作的持續(xù)進(jìn)行,越來(lái)越多的火電廠安裝了脫硫裝置,脫硫石膏排放量迅猛增長(zhǎng)。為防止大量脫硫石膏堆積如山,產(chǎn)生二次污染,高效利用脫硫石膏已經(jīng)迫在眉睫。脫硫石膏形成于液相環(huán)境中,具有純度高、品質(zhì)穩(wěn)定、濕態(tài)粉體等特點(diǎn),非常適合于用常壓鹽溶液法來(lái)制備α-半水脫硫石膏。 采用常壓鹽溶液法將脫硫石膏制備成α-半水脫硫石膏,并利用調(diào)晶劑技術(shù)調(diào)節(jié)α-半水脫硫石膏晶體形貌。試驗(yàn)中發(fā)現(xiàn),反應(yīng)介質(zhì)NaCl溶液濃度及反應(yīng)溫度對(duì)脫硫石膏的脫水反應(yīng)進(jìn)程及α-半水脫硫石膏晶體形貌有較大影響:較低的NaCl溶液濃度及反應(yīng)溫度下,脫硫石膏無(wú)法進(jìn)行脫水,α-半水脫硫石膏無(wú)法生成;二水石膏脫水反應(yīng)可以進(jìn)行的最低NaCl濃度為10%,最低反應(yīng)溫度為92.5℃;此時(shí)二水石膏脫水反應(yīng)速率較慢,所得α-半水脫硫石膏晶體尺度較大;隨著NaCl溶液濃度及反應(yīng)溫度的增大,脫硫石膏脫水反應(yīng)速率變快,但所得α-半水脫硫石膏晶體尺度隨之變小。 在調(diào)晶劑技術(shù)應(yīng)用研究中發(fā)現(xiàn),有機(jī)酸調(diào)晶劑結(jié)構(gòu)與調(diào)晶效果有很大關(guān)系。一元有機(jī)酸無(wú)調(diào)晶效果;二元及多元有機(jī)酸中,相鄰羧基間距為3個(gè)C-C的調(diào)晶劑才具有較佳的調(diào)晶效果,而其他調(diào)晶劑則不具有調(diào)晶效果。二元有機(jī)酸調(diào)晶劑是通過(guò)兩個(gè)羧基的協(xié)同作用產(chǎn)生調(diào)晶效果的,因此在雙鍵存在的條件下,由于反式結(jié)構(gòu)中的兩個(gè)羧基協(xié)同作用較順式結(jié)構(gòu)更為困難,其調(diào)晶效果較順式結(jié)構(gòu)要弱。 調(diào)晶劑的作用機(jī)理一直是一個(gè)難以解決的問(wèn)題。通過(guò)SEM及EDS、XPS等手段,直接證明了有機(jī)酸調(diào)晶劑通過(guò)化學(xué)吸附作用于α-半水脫硫石膏晶體(111)面,從而阻礙α-半水脫硫石膏在C軸方向上的生長(zhǎng),改變?chǔ)?半水脫硫石膏晶體的生長(zhǎng)習(xí)性,平衡α-半水脫硫石膏在各個(gè)方向上的生長(zhǎng)速率,達(dá)到調(diào)節(jié)α-半水脫硫石膏晶體形貌的效果。同時(shí)發(fā)現(xiàn),無(wú)機(jī)鹽類調(diào)晶劑對(duì)常壓鹽溶液法制備α-半水脫硫石膏無(wú)影響,金屬離子不會(huì)吸附于α-半水脫硫石膏晶體(111)晶面上,也不會(huì)吸附于α-半水脫硫石膏晶體(110)晶面上。在有機(jī)酸與無(wú)機(jī)鹽調(diào)晶復(fù)合作用下,起調(diào)晶作用的仍然只是有機(jī)酸調(diào)晶劑。
[Abstract]:Desulphurized gypsum is the main product of limestone / lime wet flue gas desulfurization technology. With the development of energy saving and emission reduction in China, more and more thermal power plants have installed desulphurization units, and the emissions of desulfurized gypsum are increasing rapidly. In order to prevent a large amount of desulphurized gypsum from accumulating and producing secondary pollution, it is urgent to utilize desulfurized gypsum efficiently. Desulphurized gypsum is formed in liquid environment and has the characteristics of high purity, stable quality and wet powder. It is very suitable for preparing 偽 -hemihydrate desulphurization gypsum by salt solution under normal pressure. The desulfurized gypsum was prepared by normal pressure salt solution method, and the crystal morphology of 偽 -hemihydrate desulphurization gypsum was adjusted by crystal adjusting agent. It is found that the concentration of NaCl solution and reaction temperature have great influence on the dehydration process of desulfurized gypsum and crystal morphology of 偽 -hemihydrate desulphurization gypsum. At lower NaCl solution concentration and reaction temperature, desulfurization gypsum cannot dewatering. 偽-hemihydrate desulphurization gypsum can not be formed; The lowest NaCl concentration and reaction temperature are 10 and 92.5 鈩，

本文編號(hào)：2381029