本文選題：高純五氧化二釩　切入點(diǎn)：結(jié)晶　出處：《中國(guó)科學(xué)院大學(xué)(中國(guó)科學(xué)院過(guò)程工程研究所)》2017年碩士論文

【摘要】：高純五氧化二釩是制備釩及釩化合物的基礎(chǔ)原料,具有優(yōu)良的物理和化學(xué)性能而成為研究熱點(diǎn),但制備高純五氧化二釩過(guò)程產(chǎn)生廢水、廢氣和廢渣污染環(huán)境。為此,本文針對(duì)釩渣制備99.9%五氧化二釩過(guò)程產(chǎn)生的除硅渣、除鉻渣、結(jié)晶偏釩酸銨上層液和洗液中的有價(jià)元素進(jìn)行回收和利用,并對(duì)反萃結(jié)晶偏釩酸銨工藝進(jìn)行優(yōu)化,主要研究?jī)?nèi)容及結(jié)果如下:(1)使用H2SO4浸出除硅廢渣并過(guò)濾,濾液中加入回收高純偏釩酸銨上層液中的氨氮制備硫酸銨溶液(300～400g/l,PH=1.5～2.8),在溫度40℃,PH=2.6～2.8,NH4+:Al3+(摩爾比)=1.2:1,結(jié)晶硫酸鋁銨。結(jié)晶母液中殘留少量A13+和V5+返回含釩浸出液,并補(bǔ)加硫酸鋁繼續(xù)除硅(鋁硅摩爾比0.8:1),再調(diào)pH=8.0～8.5去除殘留的A13+,含釩浸出液中的硅和A13+可降低到20mg/L以下。(2)使用焦亞硫酸鈉還原處理后含鉻萃余液,焦亞硫酸鈉加入理論質(zhì)量1.15～1.2倍,再加入碳酸鈉中和產(chǎn)生含鉻渣和廢水,廢水Cr6+0.5mg/L,COD300mg/L,鉻渣再經(jīng)水洗鈉離子含量可由6.5%降至2.4%。將鉻渣與氫氧化鉻按1:1混合,放于馬弗爐在1300-1350℃下煅燒得到為氧化鉻,在單位爐料反應(yīng)熱為2.98×103KJ,配鋁系數(shù)為0.97冶煉金屬鉻(Cr≥98.5%),雜質(zhì)滿足JCr-99A要求。(3)通過(guò)多種樹(shù)脂對(duì)比篩選出PH值使用范圍廣,溶液溫度適應(yīng)性強(qiáng)的D296樹(shù)脂作為吸附材料,對(duì)反萃結(jié)晶偏釩酸銨上層液和偏釩酸銨洗液中的釩進(jìn)行回收。D296樹(shù)脂吸附服從Freundlioh等溫吸附曲線,n=4.6樹(shù)脂對(duì)釩的吸附容易進(jìn)行,PH=3.5時(shí)吸附釩最高為278mg/g。D296樹(shù)脂吸附釩為吸熱反應(yīng)△H=7.44KJ/mol,吸附反應(yīng)符合Boyd液膜公式,吸附釩歷程以液膜擴(kuò)散為主。料液初始pH值10.5、室溫、D296樹(shù)脂/料液比為1g/100mL時(shí)吸附效果最佳,負(fù)載樹(shù)脂使用3mol/LNaOH解析,釩脫除率均在95%以上,且樹(shù)脂重復(fù)使用性能穩(wěn)定。(4)氨水與伯胺富釩有機(jī)相以1:4比例混合,反萃和結(jié)晶偏釩酸銨共同進(jìn)行,攪拌槳轉(zhuǎn)速200r/min,溫度40℃,添加偏釩酸銨為總量的0.8%作為晶種,反應(yīng)2.5小時(shí),得到的偏釩酸銨的粒徑最大為59.15μm。
[Abstract]:High purity vanadium pentoxide is the basic raw material for the preparation of vanadium and vanadium compounds. It has become a research hotspot because of its excellent physical and chemical properties. However, the process of preparing high purity vanadium pentoxide produces waste water, waste gas and waste residue to pollute the environment. In this paper, desilication slag, chromium removal slag, crystal ammonium metavanadate upper liquid and washing solution produced by the preparation of 99.9% vanadium pentoxide from vanadium slag were recovered and utilized. The process of stripping crystalline ammonium metavanadate was optimized. The main contents and results of this study are as follows: (1) H2SO4 is used to leach and filter the silicon residue. Ammonium sulfate solution was prepared by adding ammonia nitrogen from the upper liquid of high purity ammonium metavanadate to produce ammonium sulfate solution of 400 g / L PH1. 5 and 2. 8% NH 4: Al 3 at 40 鈩，

本文編號(hào)：1654491