發(fā)布時間：2019-01-12 07:57

【摘要】：隨著國家電網(wǎng)、通信網(wǎng)絡等行業(yè)的迅猛發(fā)展,對鐵塔的需求日益劇增,鐵塔構(gòu)件進行防腐處理前,常采用稀鹽酸清洗以去除其表面的疏松氧化層。該酸洗廢水Fe2+、Zn2+含量高,pH值低,有較強腐蝕性,目前尚未有經(jīng)濟合理的處理方案。因此,回收利用酸洗廢液生產(chǎn)高附加值產(chǎn)品越來越受到人們的重視。針對某鐵塔鋼構(gòu)廠的氯化亞鐵廢酸液,在分析了其基本成分和性質(zhì)的基礎上,開發(fā)了一種氯化亞鐵廢酸液回收利用的新工藝,該工藝主要包括降溫結(jié)晶法回收廢酸液制備氯化亞鐵、氯化亞鐵制備氧化鐵黃晶種、鐵黃晶種的生長三個步驟。該工藝流程具有能量消耗低、生產(chǎn)周期短、產(chǎn)量大、廢液資源化利用率高等優(yōu)點,成功將廢酸液“變廢為寶”。本文主要研究內(nèi)容如下：(1)加熱濃縮-降溫結(jié)晶法回收制備氯化亞鐵,通過Aspen Plus軟件模擬和優(yōu)化,采用四效蒸發(fā)-降溫結(jié)晶法制備氯化亞鐵晶體,設置第一效蒸發(fā)器壓力5atm、汽化分率0.09；第二效蒸發(fā)器壓力3 atm、溫度143.65℃；第三效蒸發(fā)器壓力1 atm、溫度113.95℃；第四效蒸發(fā)器壓力0.2 atm、溫度76.45℃；并通過結(jié)晶器降溫至25℃結(jié)晶,得到氯化亞鐵晶體。根據(jù)模擬結(jié)果,每蒸出lkg水,四效蒸發(fā)比直接加熱濃縮-降溫結(jié)晶法節(jié)約能量67.4%,大大提高了降溫結(jié)晶法回收廢酸液的能量利用效率。(2)設計并制作了一種氧化鐵黃顏料制備的氣液固三相反應器,并利用該反應器開展了氧化鐵黃晶種制備、晶種生長的實驗研究。首先,考察了溫度、壓力、初始Fe(OH)2濃度對鐵黃晶種生成速率的影響,得到了鐵黃晶種生成速率的關系式。結(jié)果表明,常溫下,在三相反應器內(nèi),增加空氣流量、液相流量、原料液濃度及反應壓力,降低Fe(OH)2膠體顆粒粒徑,均有利于氧化鐵黃晶種的生成。氣液固三相反應器中,晶種制備的最佳工藝條件為：氣相流量V=700 L/h、液相流量L=70 L/h、初始pH=7.5、Fe(OH)2膠體顆粒700 nm、初始Fe(OH)2濃度C=0.2～0.6mol/L、反應器壓力P=0.1～0.5MPa、反應溫度20～30℃。其次,將制得的晶種送入三相反應器內(nèi)實現(xiàn)晶種的長大,控制反應溫度120℃,反應壓力3atm,反應15-25min后,經(jīng)過濾、洗滌、干燥等處理后得到氧化鐵黃樣品,并通過SEM、 XRD等技術對樣品進行了分析和評價,所得氧化鐵黃顏料達到了我國化工行業(yè)一級標準。(3)設計并組裝了氧化鐵黃連續(xù)化生產(chǎn)的實驗裝置,考察了Fe(OH)2初始濃度和進料流量對氧化鐵黃制備的影響,獲得了三塔串聯(lián)氧化鐵黃制備的最佳工藝條件：氫氧化亞鐵進料流量20 L/h、進料濃度0.3 mol/L、循環(huán)槽操作循環(huán)比3-5、晶種制備階段填料塔溫度25℃,壓力1 atm、晶種生長階段溫度120℃,壓力4 atm。
[Abstract]:With the rapid development of national power grid, communication network and other industries, the demand for iron tower is increasing day by day. Before anticorrosion treatment of tower components, dilute hydrochloric acid is often used to clean the loose oxidation layer on its surface. The acid pickling wastewater has high Fe2, high Zn2 content, low pH value and strong corrosiveness, so there is no economical and reasonable treatment scheme at present. Therefore, people pay more and more attention to the recovery and utilization of acid pickling waste liquid to produce high added value products. Based on the analysis of the basic composition and properties of ferrous chlorinated waste acid liquid in a steel tower steel construction plant, a new process for recovering and utilizing ferrous chlorinated waste acid liquid was developed. The process includes three steps: recovery of waste acid solution to produce ferrous chloride, preparation of iron oxide yellow seed and growth of iron yellow crystal by cooling crystallization method. The process has the advantages of low energy consumption, short production cycle, large output and high utilization ratio of waste liquid. The main contents of this paper are as follows: (1) Ferrous chloride crystals were prepared by four-way evaporation-cooling crystallization method through Aspen Plus software simulation and optimization. First effect evaporator pressure 5 atm, vaporization rate 0.09; Second effect evaporator pressure 3 atm, temperature 143.65 鈩，

本文編號：2407532