腐植酸对Na2CO3-NaHCO3溶液加工铀矿石的影响

阐述了腐植酸对采用Na2CO3-NaHCO3溶液加工铀矿石过程的影响。铀矿石中存在的腐植酸导致Na2CO3-NaHCO3溶液浸出,使铀的浸出率偏低。在季铵-煤油溶液从Na2CO3-NaHCO3-[UO2(CO3)3]4--H2O体系中萃取时,铀的萃取效率明显下降,产生乳化,生成大量三相物,并且两相分离时间大大延长,降低了萃取设备的生产能力;在采用NaOH从Na2CO3-NaHCO3-[UO2(CO3)3]4--H2O体系沉淀铀的过程中,NaOH单耗量显著增大、沉淀母液中ρ(U)值上升较多。腐植酸对(NH4)2CO3-NH4OH溶液从负载铀的季铵-煤油溶液中反萃取-结晶三碳酸铀酰铵(AUC)过程,没有显示有害影响,晶体形态完整无缺陷,粗晶产率仍高于80%。     

N_(235)对废水中艳红B络合萃取的实验研究

在室温下,以三烷基叔胺(N235)作为络合剂,分别以煤油、磺化煤油和正辛醇作为稀释剂对艳红B溶液进行萃取实验。结果表明,三种稀释剂对艳红B萃取效果为正辛醇磺化煤油煤油。在最佳萃取条件下:络合剂与稀释剂体积比为3∶1,萃取剂与艳红B溶液体积比为1∶5,溶液初始pH=2.0时,N_(235)+正辛醇的萃取体系单次萃取率可达98.7%。在此基础上用NaOH溶液对其萃取相进行反萃,单次反萃率达到94.5%。反萃后得到的萃取剂可循环使用,回收后的萃取剂对模拟染料废水艳红B溶液COD的去除效果与新鲜萃取剂相当。     

N235萃取回收某铀矿高压浸出液中的铀

采用N235从某铀矿的高压浸出液中萃取回收铀。研究确定了合适的萃取条件为:萃取剂组成为5%N235+95%磺化煤油溶液,接触相比O/A为3︰2,萃取两相混合时间2 min,负载有机相操作容量为3.8 g/L,4级逆流萃取,铀的萃取率达到99%以上;负载有机相100 g/L碳酸钠溶液3级逆流反萃取,铀反萃取率达到99%以上;制备的重铀酸钠产品达到行业一级品标准。     

络合萃取法对煤制气高浓度含酚废水的资源化处理

用磷酸三丁酯(TBP)为萃取剂和煤油为稀释剂,对煤制气过程中产生的高浓度含酚废水进行了络合萃取处理,并用氢氧化钠溶液为反萃取剂对负载有机相进行了反萃取。分别研究了废水pH、TBP体积分数对萃取及氢氧化钠溶液浓度对反萃取的影响,并对萃取和反萃取过程中有机相的重复使用问题进行了探讨。结果表明,当废水的pH为3～6时,萃取率可达90%以上,CODCr去除率达到80%以上;当氢氧化钠质量分数为4%～10%时,反萃取率可达80%以上;TBP-煤油有机相可在萃取和反萃的过程中多次重复使用。     

撞击流-旋转填料床内络合萃取法分离醋酸稀溶液实验研究

采用撞击流-旋转填料床作为萃取设备,选用磷酸三丁酯(TBP)为萃取剂(稀释于煤油中),对络合萃取法分离醋酸稀溶液过程进行了实验研究.研究结果表明:在适宜的操作条件下,撞击流旋转填料床对于磷酸三丁酯与醋酸的络合萃取过程具有良好的萃取传质性能,萃取级效率高达98%以上;采用三级错流萃取流程,获得了94.0%的醋酸萃取率,取得了较好的分离效果.以质量分数15%的氢氧化钠溶液为反萃取剂,经反萃取操作后实现萃取剂的再生,再生后的萃取剂萃取性能无明显变化.综合考虑了萃取剂、萃取设备及萃取工艺对于络合萃取过程的影响,为络合萃取技术在醋酸稀溶液回收中的应用奠定了基础.     

络合萃取法在2-萘酚废水处理中的应用研究

采用络合萃取法,以三烷基胺和磷酸三丁酯为萃取剂、煤油为稀释剂处理2-萘酚β-盐母液废水。试验结果表明：采用20％三烷基胺-20％磷酸三丁酯-60％煤油的混合型络合萃取剂对2．萘酚废水进行萃取具有较高的COD脱除率。     

从电镀污泥浸出液中选择性萃取铜的研究

采用M5640-磺化煤油作为萃取剂,H2SO4为反萃剂,对电镀污泥浸出液中的铜进行选择性萃取实验,确定了萃取铜及反萃的最佳工艺参数。结果表明,实验采用二级萃取,萃取剂浓度为5％,VO/VA=1：1,混合时间为2min时,铜的萃取率可达到9996以上,另外采用已优化的反萃工艺参数,铜的反萃率可达99％以上。同时,萃取剂对Ni、Zn的共萃率较低,表明M5640-磺化煤油体系对电镀污泥液中铜的萃取选择能力较高,可以达到与溶液中Ni、Zn有较好的分离效果。     

酚醛树脂生产废水中酚的络合萃取及资源化处理

采用离心萃取器对高浓度含酚废水进行萃取处理-反萃取处理。分别研究萃取剂组成、相比对萃取率的影响,并对萃取剂的重复使用进行了实验。结果表明,30%TBP-煤油为萃取剂、相比3∶1、转速为3500 r/min、单级离心萃取后,萃取率达99.69%,该萃取体系在萃取和反萃过程中可循环使用。     

废钒催化剂综合利用的实验研究

研究了以废钒催化剂为原料,经水浸-还原酸浸-萃取-沉钒等环节制取五氧化二钒、硫酸钾、液体硅酸钠的方法。考察了以三正辛胺（TOA）-仲辛醇-煤油溶液为萃取液提钒的最佳工艺条件： 将废钒催化剂磨碎至 375 μm左右,经过水浸、还原酸浸后,合并其浸出液进行氧化,在水相pH为2.3时,用9%的TOA-3%的仲辛醇-88%（均为质量分数）的煤油溶液萃取, 在浸取时间为2.5 min条件下, 经三级萃取, 钒的萃取率达99%以上;在pH>8、反萃取剂为0.25 mol NaOH+0.25 mol NaCl、反萃时间为3 min条件下, 经三级反萃, 钒的反萃取率达99.4%。在此工艺条件下, 钒、钾的回收率分别达到91.5%和93.8%,产品五氧化二钒、硫酸钾、液体硅酸钠的主要成分含量均达到相应国家标准要求。     

DCH-18-C-6/乙酸乙酯萃取体系萃取分离铀(Ⅵ)的研究

以二苯并-18-冠醚-6(DCH-18-C-6)作为萃取剂,采用溶剂萃取法萃取分离溶液中的铀(Ⅵ),研究了稀释剂、盐析剂、介质酸度等条件对萃取率的影响,确定了乙酸乙酯为稀释剂,0.1 mol/L的KH2PO4为盐析剂、水杨酸为酸性介质的溶剂萃取体系。该萃取体系在选定的条件下,对1×10-4mol/L的铀酰离子一次萃取率可达82.5%。     

以尿素和复合活化剂提取水溶腐植酸的新技术研究

阐述了以水为介质,以尿素和复合活化剂直接从风化煤中提取水溶性腐植酸新技术。结果表明,腐植酸提取率达70%以上,新技术提取的水溶腐植酸交换容量5.32、总酸性基含量5.84、E4/E6值4.92,都比碱提腐植酸的相应数值(4.59、5.70、3.70)较高,pH值较低,属于高纯度(灰份6.09%)、高活性、环境安全的农用含氮(30.38%)腐植酸产品。该技术克服了传统的碱液提取腐植酸工艺的生产成本高,引入的钠离子和其他无机盐对土壤的潜在危害,腐植酸易絮凝,残渣和工艺废水碱性强、污染环境等弊端,可以替代传统的碱液提取腐植酸的工艺。     

准格尔旗风化煤中提取腐植酸的工艺研究

以内蒙古准格尔旗风化煤为原料,研究了风化煤中腐植酸的提取工艺。考察了混合提取液的组成和用量、提取温度、提取时间、固液比等因素对提取收率的影响。测定了风化煤中腐植酸的含量可达到60%。     

复合碱型腐植酸型煤粘结剂的特性研究

研究了从云南褐煤提取型煤腐植酸粘结剂的过程,主要考察了煤碱质量比和不同碱性添加物包括NaOH,Na4P2O7,Na2CO3和K2CO3等对腐植酸提取率的影响,并进行了成本估算。结果表明,在利用NaOH的条件下,煤碱质量比在10∶1与12∶1之间获得较好提取效果;与利用单一NaOH添加剂相比,在总碱量略有减少的前提下,用Na4P2O7和Na2CO3替代部分NaOH使腐植酸的提取率增加18.4%,粘结剂的粘度提高30%,经济成本下降2.6%。腐植酸钾型型煤的气化效果好于钠型,跌落强度基本相同。     

EXTRACTIVE SEPARATION OF URANIUM AND ZIRCONIUM SULFATES BY AMINES

ABSTRACT

This paper describes an amine extraction process for zirconium and uranium separation. The behaviour of an extraction system containing uranium (VI) sulfate, zirconium (IV) sulfate, 0.2 and 0.5 M sulfuric acid (as the original aqueous phase), tertiary amine tri-n-lauryl- amine or primary amine Primene JMT in benzene (as the original organic phase) is discussed on the basis of equilibrium data.

The measured dependences show that the degree of extraction of zirconium at the sulfuric acid concentration of 0.5 M and above is only slightly affected by a presence of uranium in solution. From this surprising behaviour it follows that zirconium may be employed for the displacement of uranium from the organic phase. This effect is more pronounced with the primary amine Primene JMT than with TLA.     

Isolation and characterization of humic acids from Alberta oil sands and related materials

Thirteen humic acid samples were isolated from a number of oil sand feedstocks using 0.5 N NaOH or a mixture of 0.1 N NaOH + 0.1 M Na₄P₂O₇. The feedstocks included three different grades of Athabasca oil sand, two samples of overburden, a sample of centrifuge tailings from the Syncrude Canada Ltd plant in Alberta and a heavy minerals fraction from oil sand tailings containing adsorbed organic matter. Based on the extraction efficiency of the two solvents it appears that the humic acids from oil sand and overburden feedstocks are strongly associated with calcium, while the humic acids from other feedstocks could be bound to non-silicate aluminum and/or iron. Comparison of analytical data for the various humic acid samples with corresponding data for humic acids from subbituminous coal, peat, soil and asphaltenes from bituminous feedstock, shows the similarity of these humic acids to those from subbituminous coal. Examination of the elemental analyses in terms of a van Krevelen diagram shows that most of the data either overlap or fall directly in the region of the recent and shallow kerogens. This kind of organic matter has very little potential for oil production, suggesting that the origin of this organic matter could be different from that of the greater part of the bitumen of the Athabasca oil sands.     

Factors Influencing Phase Disengagement Rates in Solvent Extraction Systems Employing Tertiary Amine Extractants

Abstract

Phase disengagement rate is a critical property in determining the usefulness of a particular solvent extraction system in hydro-metallurgy. A survey of a number of commercial tertiary amine extractants of the type used in uranium extraction hydrometallurgy has been carried out to suggest whether structural factors influence phase disengagement behavior and to provide a useful comparison of different amines with regard to phase disengagement and uranium extraction. The amines ((C_nH_2n+1)₃N) were chosen to cover a range of alkyl chain lengths including straight-chain and branched-chain compositions, and the chemical makeup of the liquid-liquid systems closely paralleled that of the systems used in the Amex uranium extraction process. Batch phase disengagement tests showed significant trends with respect to amine structure and composition using acid sulfate solutions with or without added colloidal silica and actual ore leach solutions as the aqueous phase. In general, organic continuous (OC) phase disengagement became slower with increasing n (number of carbons per chain) whether branched or linear chain, but for any given n, the branched chain amines had much faster OC phase disengagement than the linear chain amines. A key structural factor affecting OC phase disengagement was found to be the backbone chain length (longest chain in each alkyl group) since the OC phase disengagement measurements could be correlated vs backbone chain length on a single curve regardless of whether the amine was branched or linear. Aqueous continuous (AC) phase disengagement rate was rapid for the acid sulfate solution but decreased greatly with decreasing for the acid sulfate solution but decreased greatly with decreasing n when colloidal silica was added or when leach solution was used. With both leach and colloidal silica solutions, AC phase disengagement was correlated with wetting behavior or the amine systems on a glass (silicate) surface. A model based on silica attachment to the liquid/liquid interface was suggested to explain the stabilization of AC dispersions by silica and the related problem of interfacial crud formation. In addition to faster AC phase disengagement and less emulsion (crud) stabilization, the larger molecular weight amines (n ≥ 10) were found to have higher uranium extraction coefficients and lower tendencies to form third phases. Presumably, solubility losses to the aqueous phase are also lower. The results suggest that the performance of some Amex systems may be improved by using branched chain tertiary amine extractants of higher molecular weight than are now normally used.     

Liquid–Liquid Extraction of Uranium from Phosphoric Acid by HDEHP–CYANEX-921 Mixture

The extraction of uranyl ions from different phosphoric acid media by CYANEX-921 (a commercial trioctyl phosphine oxide) mixed with di-2-ethylhexyl phosphoric acid diluted with odourless kerosene has been investigated. The effect of phosphoric acid, CYANEX-921 and HDEHP concentrations, as well as temperature on the extraction were studied. The extraction rate for UO₂²⁺ transfer from 5 M phosphoric acid to the organic phase containing a CYANEX-921–HDEHP mixture in a single drop column without external force was also studied. The mass transfer of uranium in the organic extractant single drop was investigated in terms of drop size, uranium concentration as well as other parameters. The extraction rate was found to be mainly dependent on uranium, HDEHP and phosphoric acid concentrations, and found to be mainly controlled by diffusion in the single drop. Further, it was found that CYANEX-921 can substitute TOPO to synergise the extraction of UO₂²⁺ by HDEHP. © 1997 SCI.     

硝化处理腐殖酸的工艺研究

通过实验测定了泥炭中腐殖酸的含量,研究了硝化处理腐殖酸的工艺。实验表明从泥炭中提取的腐殖酸的含量会随硫酸的浓度（2～4mol／L）增大而增大,而把泥炭硝化再经碱溶解酸沉淀,与使用相同浓度的酸相比．腐殖酸的含量增加近5％．此实验为分离提取腐殖酸肥料提供了一些必备的基本的参考依据。     

从高钙油田水老卤提取硼酸的研究

以青海高钙油田水老卤为原料,考察了萃取相比（有机相与水相的体积比）、异辛醇体积分数、反萃相比等因素对硼萃取和反萃的影响。结果表明：在以磺化煤油为稀释剂、异辛醇体积分数为50%、萃取相比为1、萃取时间为15 min条件下,经过3级逆流萃取,硼的萃取率达到93.22%;在盐酸浓度为0.1 mol/L、反萃相比为1、反萃时间为15 min条件下,经过3级逆流反萃,硼的反萃率达到98.25%。采用异辛醇萃取—盐酸反萃—高温蒸发-低温冷却—重溶-冷却—过虑洗涤—干燥的工艺,可制得符合GB/T 538—2006《工业硼酸》要求的硼酸产品。