CAS OpenIR
钒渣制备99.9%五氧化二钒清洁生产研究
Alternative TitleStudy on the clean production of 99.9% vanadium pentoxide from vanadium slag
王向阳
Thesis Advisor曹宏斌
2017-03
Degree Grantor中国科学院大学
Degree Name硕士
Degree Discipline化学工程
Keyword高纯五氧化二钒,结晶,金属铬, 离子交换
Abstract

高纯五氧化二钒是制备钒及钒化合物的基础原料,具有优良的物理和化学性能而成为研究热点,但制备高纯五氧化二钒过程产生废水、废气和废渣污染环境。为此,本文针对钒渣制备99.9%五氧化二钒过程产生的除硅渣、除铬渣、结晶偏钒酸铵上层液和洗液中的有价元素进行回收和利用,并对反萃结晶偏钒酸铵工艺进行优化,主要研究内容及结果如下: (1)使用H2SO4浸出除硅废渣并过滤,滤液中加入回收高纯偏钒酸铵结晶上层液中的氨氮制备硫酸铵溶液(300~400g/l,PH=1.5~2.8),在温度40℃,PH=2.6~2.8,NH4+:Al3+(摩尔比)=1.2:1,结晶硫酸铝铵。结晶母液中残留少量Al3+和V5+返回含钒浸出液,并补加硫酸铝继续除硅(铝硅摩尔比0.8:1),再调pH=8.0~8.5去除Al3+,含钒浸出液中的硅和Al3+可降低到20mg/L以下。(2)使用焦亚硫酸钠还原处理后含铬萃余液,焦亚硫酸钠加入理论质量1.15~1.2倍,再加入碳酸钠中和产生含铬渣和废水,废水Cr6+<0.5 mg/L,COD<300mg/L,铬渣再经水洗钠离子含量可由6.5%降至2.4%。将铬渣与氢氧化铬按1:1混合,放于马弗炉在1300-1350℃下煅烧得到为氧化铬,在单位炉料反应热为2.98×103KJ,配铝系数为0.97冶炼金属铬(Cr≥98.5%),杂质满足JCr-99A要求。(3)通过多种树脂对比筛选出PH值使用范围广,溶液温度适应性强的D296树脂作为吸附材料,对反萃结晶偏钒酸铵上层液和洗液中的钒进行回收。D296树脂吸附服从Freundlioh等温吸附曲线,n=4.6树脂对钒的吸附容易进行,PH=3.5时吸附钒最高为278mg/g。D296树脂吸附钒为吸热反应ΔH=7.44KJ/mol,吸附反应符合 Boyd 液膜公式,吸附钒历程以液膜扩散为主。料液初始pH值10.5、室温、D296树脂树脂/料液比为1g/100mL时吸附效果最佳,负载树脂使用3mol/LNaOH解析,钒脱除率均在95%以上,且树脂重复使用性能稳定。(4)氨水与富钒有机相以1:4的比例混合,反萃和结晶偏钒酸铵共同进行,搅拌桨转速200r/min,温度40°C,添加偏钒酸铵为总量的0.8%作为晶种,反应2.5小时,得到的偏钒酸铵的粒径最大为59.15μm。 ;Vanadium pentoxide with high-purity is the basic raw material for the preparation of vanadium and vanadium compounds, which has excellent physical and chemical properties and has become a research hotspot in the research field. The process of preparing vanadium pentoxide with high-purity produce waste water, waste gas and waste residue pollutes the environment. Therefore, based on the preparation of 99.9% vanadium pentoxide from vanadium slag,removal of silicon slag, removal of chromium slag, crystallization of ammonium metavanadate and the upper liquid lotion in the recovery and utilization of valuable elements. The main research contents and results are following:(1) Leaching of silica residue by H2SO4 and deep filtration,with the recovery of high purity ammoniumvanadate crystals in the upper liquid ammonia for preparation of ammonium sulfate solution (300~400g/l, PH=1.5~2.8).The crystallization of ammonium aluminum sulfate,NH4+:Al3+ (molar ratio) =1.2:1, the temperature of 40, PH=2.6~2.8. A small amount of residual in crystal liquor Al3+ and V5+:1~4g/l, will return to the crystallization solution of leaching solution containing vanadium, and aluminum sulfate to remove silicon, adding aluminum silicon molar ratio of 0.8:1, can make the silicon content reduced to below 50mg/L, then adjust the PH=8.0~ 8.5 to remove Al3+, can be in the solution of Si and Al3+impurity content is reduced to below 20mg/L.(2) The use of sodium pyrosulfite reduced chromium raffinate, sodium metabisulfite is added to the theoretical quality of 1.15~1.2 times, adding sodium carbonate and produce chromium slag and wastewater, wastewater Cr6+< 0.5 mg/L, COD < 300mg/L, chromium slag after washing the sodium ion content can be reduced from 6.5% to 2.4%. The chrome slag and chromium hydroxide mixed by 1:1, put in the muffle furnace at 1300-1350℃ for calcination of chromium oxide, the reaction heat of unit charge is 2.98×103KJ,with a coefficient of 0.97 aluminum chromium metal smelting (Cr≥98.5%), meet the requirements of JCr-99A impurity. (3) Through the comparison of various resins, the D296 resin which has wide application range of pH value and strong solution temperature is selected as the adsorption material. The adsorption of D296 resin obeys the Freundlioh isotherm adsorption curve, n=4.6 the adsorption of resin for vanadium is easy to carry out, and PH=3.5 the adsorption vanadium of resin is 278mg/g. Adsorption of vanadium by D296 resin as endothermic reactionΔH=7.44KJ/mol, and the adsorption reaction was in accord with Boyd liquid film formula. When the initial pH value was 10.5, the room temperature and the resin / liquid ratio was 1g/100mL, the adsorption effect was the best.Loaded resin Using 3mol/LNaOH analysis, vanadium removal rate was above 95%, and the resin reuse performance is stable. (4) Ammonia and vanadium rich organic phase mixed by 1:4, stripping and crystallization of ammonium metavanadate together, stirring speed 200r/min, the temperature of 40, adding ammonium metavanadate for 0.8% of the total as a seed, reaction for 2.5 hours, the ammonium metavanadate maximum diameter of 59.15μm. 

Language中文
Document Type学位论文
Identifierhttp://ir.ipe.ac.cn/handle/122111/26959
Collection中国科学院过程工程研究所
Recommended Citation
GB/T 7714
王向阳. 钒渣制备99.9%五氧化二钒清洁生产研究[D]. 中国科学院大学,2017.
Files in This Item:
File Name/Size DocType Version Access License
钒渣制备99.9%五氧化二钒清洁生产研究(2016KB)学位论文 限制开放CC BY-NC-SAApplication Full Text
Related Services
Recommend this item
Bookmark
Usage statistics
Export to Endnote
Google Scholar
Similar articles in Google Scholar
[王向阳]'s Articles
Baidu academic
Similar articles in Baidu academic
[王向阳]'s Articles
Bing Scholar
Similar articles in Bing Scholar
[王向阳]'s Articles
Terms of Use
No data!
Social Bookmark/Share
All comments (0)
No comment.
 

Items in the repository are protected by copyright, with all rights reserved, unless otherwise indicated.