高铁低镍溶液中不同工艺条件对氨沉淀法提取镍的影响

本文研究了不同工艺条件对硫酸铁和硫酸镍的混合溶液中镍的提取效果的影响.向溶液中滴加氨水将溶液中的铁离子沉淀,过滤得含镍的滤液.改变溶液中Fe3+的浓度、沉淀温度及沉淀pH值来控制Fe(OH)3沉淀对镍的吸附.此外,还研究了絮凝剂对镍吸附的影响.通过正交试验,得出提取镍的最佳实验条件为:20℃,溶液铁离子浓度为0.4 m...     

铁离子对土状铜矿中铜浸出影响研究

考察Fe3+浓度、Fe3+/Fe2+对土状铜矿中铜浸出率的影响,分析了酸浸过程中铁离子提高铜浸出率的机理。结果表明,在矿浆浓度30%、酸浓度36.8g/L、12.0g/L硫酸铁溶液浸出土状矿48h后,铜浸出率为62.4%,与无铁时铜浸出率相比提高了10个百分点。其中有92.6%游离氧化铜、70.3%结合氧化铜、35.6%次生硫化铜和11.8%原生硫化铜被浸出,除原生硫化铜外,均比无铁时有明显提高。并且随着Fe2+/Fe3+的降低,铜浸出率逐渐增加。增加Fe3+浓度提高了溶液电位,从而提高铜浸出率。     

一种含镓酸性溶液选择性富集制备富镓渣的方法

正本发明涉及一种含镓酸性溶液选择性富集制备富镓物的方法,其特征在于:该含镓酸性溶液为含镓明矾石矿硫酸浸出溶液,将该含镓酸性溶液在一定温度、pH、时间、富镓载体等条件下实现Ga的选择性富集,即在酸性溶液中Ga沉淀富集的同时Al、K     

五钠沉铟的工艺研究

以三聚磷酸钠为沉淀剂,研究了模拟含铟加压浸出液和实际含铟加压浸出液中影响铟沉淀率的因素。结果表明:常温下,pH值范围在2.5～2.7,搅拌时间为1.5h,三聚磷酸钠与铟摩尔比为0.91∶1,体系中Fe3+浓度小于0.04g.L-1时,铟的沉淀率高达95%以上。溶液中Fe3+对铟的沉淀率有显著影响,当体系中Fe3+浓度为4.8g.L-1时,铟的沉淀率从96%降到34%,Fe2+,Cu2+,Zn2+等金属离子对铟的沉淀率没有影响,温度对铟的沉淀率也没有影响。并提出可能的反应机制:用三聚磷酸钠沉铟,首先析出含羟基的盐In2OHP3O1.09H2O,随后转变为InH3(PO4)2.4H2O。     

选择性磷酸沉淀分离铬铁的新工艺

针对酸性水溶液中铬铁分离难题,基于Fe3+还原预处理,提出选择性磷酸沉淀铬分离铬铁的方法。研究沉淀剂Na₃PO₄用量、溶液初始pH值、反应温度及保温时间等对铬铁分离的影响,所得较优工艺条件为:溶液初始pH值为2.0,按PO₄3-/Cr3+摩尔比0.375的量加入Na₃PO₄,90 ℃保温60 min。在上述条件下,铬沉淀率可达98.53%,铁沉淀率仅1.42%,分离效果理想。实验还证明,该方法适用于较宽的铁浓度范围,而且Cu2+、Zn2+、Ni2+及Cl-等杂质离子对选择性沉铬无明显干扰。该方法为含铬物料的铬分离提取提供了一条新的可选途径。      

硫酸体系中杂质离子对N235萃取钒的影响

含钒石煤经空白焙烧、硫酸浸出后的酸浸液中含有较高浓度的Fe3+、Al 3+、Mg2+、PO3-4等杂质离子。试验研究了这些杂质离子对N235萃取钒的影响。结果表明:同等条件下,N235对V(Ⅴ)的萃取率显著高于对V(Ⅳ)的萃取率;升高溶液pH有利于V(Ⅴ)的萃取,当pH为1时,V(Ⅴ)的单级萃取率可达97.21%;当pH=0.5时,杂质离子Fe2+对V(Ⅴ)的萃取效果影响明显,所以溶液应处于氧化环境,使V(Ⅴ)稳定存在;溶液中的磷与Fe3+质量浓度升高可强化N235对磷与Fe3+的萃取,而Al 3+质量浓度升高会降低Al 3+的萃取率,硅与Mg2+的存在对萃取钒影响较小。整体上,Fe3+、Al 3+、Mg2+、SiO2-3与V的共萃效果不明显,对钒萃取影响较小。     

铟在黄钠铁矾除铁过程中的沉淀行为

利用黄钠铁矾除铁原理,研究了沉矾过程中铟的沉淀行为。在黄钠铁矾沉铁过程中,铟离子取代黄钠铁矾中的铁离子形成类质同相晶型,形成沉淀。考察了温度、三价铁离子质量浓度、晶种质量浓度、反应时间对铟沉淀率的影响。结果表明:在温度95℃、晶种质量浓度10g/L、初始铁离子浓度5.0g/L条件下,铟沉淀率随沉淀时间延长而提高,在反应3h时,铟沉淀率达80%。     

P204从硫酸体系萃取镓性能研究

研究了P204从硫酸体系萃取镓的性能,分别考察了料液酸度、萃取剂浓度、时间、浓度等对镓萃取与反萃的影响并绘制等温线,确定并模拟逆流试验过程。结果表明:料液含0.3g/L Ga^3+,pH=1.2,有机相采用20%P204(体积分数)+磺化煤油,按相比O/A=1∶3,25℃萃取8min,经过3级逆流萃取,镓萃取率可达到99.33%,负载有机相用1.0mol/L H2SO4溶液反萃,按相比O/A=10∶1,反萃温度25℃,反萃时间10min,经过3级逆流反萃,镓反萃率达98.99%,镓浓度富集近30倍。反萃液中的镓经氨水中和沉淀、焙烧后,可得到氧化镓产品。     

氧压酸浸炼锌流程中置换渣提取锗镓铟

为从锌精矿氧压酸浸炼锌工艺的置换渣中提取锗镓铟元素,对二段浸出-萃取分离锗镓铟铜工艺进行研究,锌电积废液用于一段浸出,H2SO4-HF混酸用于一段浸出渣的二段浸出;一段浸出液分别采用二(2-乙基已基)磷酸(P204),C3~5氧肟酸+二(2-乙基已基)(P204)磷酸及5-壬基水杨醛肟(CP150)分别萃取铟,锗镓及铜;二段浸出液用C3~5氧肟酸萃取提锗,萃余液加入氟化钠沉淀氟硅酸钠。试验结果显示,一段浸出用酸度为3.1 N的湿法炼锌电积废液,液固比4∶1,初始氧分压0.4 MPa,150℃,经3 h的二级浸出后,浸出渣率约为15%,铟镓铜锌4个元素的浸出率都达到98%,而锗浸出率约为80%;一段浸出残渣用H2SO4-HF混酸浸出,其氟/硅摩尔比4.2∶1.0,硫酸浓度为2 N温度80℃,液固比3∶1,浸出时间为5 h,一段浸出残渣中锗几乎完全浸出;一段浸出液在pH 2.0~2.2,30%二(2-乙基已基)磷酸萃取,部分铁与几乎所有的铟被萃取,用2 N盐酸反萃,铟、铁的反萃率分别为98.28%和2.79%,可达到铟铁的分离;萃铟余液用3%的氧肟酸+10%二(2-乙基已基)磷酸-煤油协萃锗、镓,铁也发生共萃,锗、镓和铁的单级萃取率均在90%以上,采用次氯酸钠反萃,锗反萃率近100%,且Ge/Ga和Ge/Fe的反萃分离系数分别为10836和318.7。用3 mol·L-1的硫酸,相比(W/O)1∶2反萃镓,镓的一次反萃率达97.5%。二段浸出液采用10%C3~5氧肟酸-煤油萃取,相比(O/W)为1.2∶1.0,锗的单级萃取率达到98.31%。经30%次氯酸钠溶液反萃,锗的一次反萃率达到98.83%,萃余液加入氟化钠,氟硅化物的沉淀率为90%左右。沉硅滤液经补充氢氟酸后返回二段沉出,锗的浸出仍可达到较完全的浸出。该工艺无废液排放,并且通过与湿法炼锌流程的物料交换而变得简化。     

芬顿法脱除硫酸锰溶液中残余有机物的研究

采用芬顿法对硫酸锰溶液中残余有机物进行氧化脱除,通过测定溶液COD值的变化来判断脱除效果。考察了溶液的初始pH、Fe2+浓度、H2O2/Fe2+摩尔比、反应时间、反应温度等对COD脱除率的影响。结果表明,在初始pH为3.50、Fe2+浓度0.03 mol/L、H2O2/Fe2+=5、30℃反应60 min时,溶液COD脱除率为75.35%     

含Ni~(2+),Fe~(3+),Mg~(2+)的硫酸盐溶液萃取分离Cu~(2+)

采用Lix984作萃取剂,煤油作稀释剂混合而成溶液萃取的有机相,从含Ni~(2+),Fe~(3+),Mg~(2+)离子的硫酸盐溶液中萃取分离Cu~(2+).实验结果表明,在一定范围内,铜萃取率随萃取剂浓度的升高、相比的增加、萃取时间的延长、初始水相pH值的增加、萃取温度的升高以及搅拌时间的延长而增加.本实验的优化条件为萃取剂体积分数达60%,相比为O∶A=2∶1,萃取时间为16 min,萃取初始水相pH值为2.5,萃取温度在25~45℃之间,搅拌速度为240 r/min.在最佳条件下,铜萃取率高达95.55%.Fe~(3+)萃取率为8.82%,Ni~(2+)的萃取率为5.47%,Mg~(2+)的萃取率为2.36%.从而达到Cu~(2+)与其它金属离子有效分离的效果.     

Ga3+ as a functional substitute for Fe3+: preparation and characterization of the Ga3+Fe2+ and Ga3+Zn2+ forms of bovine spleen purple acid phosphatase

A general method has been developed that allows the specific substitution of both iron atoms in the enzyme bovine spleen purple acid phosphatase (BSPAP), which possesses a dinuclear iron center at the active site. The approach is demonstrated by the preparation and characterization (atomic absorption spectrometry, enzyme kinetics, optical spectroscopy, and electron paramagnetic resonance spectroscopy) of two metal-substituted forms in which the ferric iron has been replaced by Ga3+: Ga3+Fe2+-BSPAP and Ga3+Zn2+-BSPAP. Both forms are colorless but exhibit enzymatic activity comparable to that of the native Fe3+Fe2+-BSPAP. Small but consistent changes in kinetics parameters and pH profiles were detected both upon substitution of Fe3+ by Ga3+ and upon substitution of Fe2+ by Zn2+. These results constitute the first evidence that the diamagnetic Ga3+ ion can serve as a functional analogue of Fe3+ in an enzyme, and suggest a novel approach for the study of the role of Fe3+ in other iron enzymes.     

Effect of aluminum ion on Fe(2+)-induced lipid peroxidation in phospholipid liposomes under acidic conditions

The effects of Al3+ on Fe(2+)-induced lipid peroxidation in phospholipid liposomes consisting of phosphatidylcholine (PC) and phosphatidylserine (PS) were examined under acidic conditions. The stimulatory effect of Al3+ on Fe(2+)-induced lipid peroxidation in the liposomes showed a biphasic response against pH variation, and the maximum stimulation was observed around pH 6.0. In addition, it was found that the stimulatory effect of Al3+ on the lipid peroxidation was dependent on the proportion of PS in the liposomes. On the other hand, the lipid peroxidation in PC liposomes was not stimulated by the addition of Al3+. From these findings, it is suggested that the Al3+ effect on Fe(2+)-induced lipid peroxidation under acidic conditions is largely dependent on the phospholipid composition. Trivalent cations such as Tb3+ and Ga3+ also stimulated Fe(2+)-induced lipid peroxidation in PC/PS liposomes under acidic conditions, but divalent cations (Zn2+ and Mn2+) showed no stimulatory effect. The extents of Fe2+ disappearance and Fe3+ formation during the reaction were enhanced by the addition of Al3+ or Ga2+, but Tb3+ had no effect on Fe2+ disappearance. The results with 1,6-diphenyl-1,3,5-hexatriene (DPH) showed that the fluorescence anisotropy of DPH-labeled PC/PS liposomes under acidic conditions was increased by the addition of Al3+. Furthermore, there is a relation between the extents of the fluorescence anisotropy of the complex and TBARS production. In contrast, the fluorescence anisotropy of DPH molecules embedded in PC liposomes was not changed by the addition of Al3+. Based on these results, a possible mechanism of the stimulatory effect of Al3+ on Fe(2+)-induced lipid peroxidation under acidic conditions is discussed.     

Identification and characterization of a protease produced by Vibrio parahaemolyticus in iron-limited medium

Two proteolytic proteins (about 43 and 90 kDa) were produced by clinical strains of Vibrio parahaemolyticus cultured in iron-limited medium. The 43 kDa-protease was partially purified by ammonium sulfate precipitation, ultrafiltration fractionation and DEAE-Sephacel chromatography. This protease had an optimum pH range of 7 to 8, and an optimum reaction temperature of about 40 degrees C. It was heat-labile, being partially inactivated by heat-treatment at 60 or 90 degrees C for 10 min. The protease hydrolyzed casein, gelatin, elastin, collagen and hemoglobin. As a chymotrypsin-like protease, it was inhibited only by the chymostatin among seven protease inhibitors tested. Activity of this protease was partially inhibited by 1 mM of Co2+, Cu2+, Zn2+ and Hg2+ and slightly enhanced by Ca2+ and Ba2+. It was completely inactivated by orthophenanthroline (OPA), and the OPA-inactivated sample was partially reactivated by Ca2+ and Fe2+. In conclusion, this 43-kDa protease of V. parahaemolyticus was an unstable neutral chymotrypsin-like metalloprotease; Ca2+ and/or Fe2+ was essential for its activity or stability.     

Selective Precipitation of Phosphate from Semiconductor Wastewater

Selective precipitation of phosphate from fluoride-containing wastewater was studied using magnesium salts. Wastewater sampled from a semiconductor manufacture was found to contain 936 mg/L of fluoride (F?), 640 mg/L of sulfate (SO42?), 118 mg/L of phosphate (PO43?), and 26.72 mg/L ammonium (NH4+). Magnesium chloride (MgCl2) was more effective than magnesium oxide (MgO) in inducing precipitation reactions between magnesium and phosphate. Effects of both molar ratio ([Mg2+]:[PO43?]) and pH were examined and experimental results were compared with those from equilibrium modeling by PHREEQC. A total of 41.72% of phosphate was removed and recovered when at molar ratio of 3:2 and pH of 10. Precipitation of phosphate increased with increasing molar ratio and 66.19% of phosphate was recovered when molar ratio was 3:1. Precipitation of phosphate increased as pH changed from 8 to 10. However, it decreased as pH increased from 10 to 12, probably because of competition between phosphate and hydroxyl (OH?) ions. Solid precipitates were characterized by field emission scanning electron microscope with energy dispersive spectrometer and X-ray diffraction. In accordance with theoretical modeling, it was found that the precipitate in pH range of 8–10 was predominantly bobierrite [Mg3(PO4)2.8H2O] and some amorphous precipitates. However, brucite [Mg(OH)2] precipitate would start to form when pH became higher than 10. Results showed that MgCl2 can be a selective precipitation reagent for phosphate removal from semiconductor wastewater since it does not form precipitate with fluoride, sulfate, and ammonium.     

Dramatic aggregation of Alzheimer abeta by Cu(II) is induced by conditions representing physiological acidosis

The cortical deposition of Abeta is an event that occurs in Alzheimer's disease, Down's syndrome, head injury, and normal aging. Previously, in appraising the effects of different neurochemical factors that impact upon the solubility of Abeta, we observed that Zn2+ was the predominant bioessential metal to induce the aggregation of soluble Abeta at pH 7.4 in vitro and that this reaction is totally reversible with chelation. We now report that unlike other biometals tested at maximal biological concentrations, marked Cu2+-induced aggregation of Abeta1-40 emerged as the solution pH was lowered from 7.4 to 6.8 and that the reaction was completely reversible with either chelation or alkalinization. This interaction was comparable to the pH-dependent effect of Cu2+ on insulin aggregation but was not seen for aprotinin or albumin. Abeta1-40 bound three to four Cu2+ ions when precipitated at pH 7.0. Rapid, pH-sensitive aggregation occurred at low nanomolar concentrations of both Abeta1-40 and Abeta1-42 with submicromolar concentrations of Cu2+. Unlike Abeta1-40, Abeta1-42 was precipitated by submicromolar Cu2+ concentrations at pH 7.4. Rat Abeta1-40 and histidine-modified human Abeta1-40 were not aggregated by Zn2+, Cu2+, or Fe3+, indicating that histidine residues are essential for metal-mediated Abeta assembly. These results indicate that H+-induced conformational changes unmask a metal-binding site on Abeta that mediates reversible assembly of the peptide. Since a mildly acidic environment together with increased Zn2+ and Cu2+ are common features of inflammation, we propose that Abeta aggregation by these factors may be a response to local injury. Cu2+, Zn2+, and Fe3+ association with Abeta explains the recently reported enrichment of these metal ions in amyloid plaques in Alzheimer's disease.     

利用含锌粉尘和铁鳞中锌和铁制备合成Ni-Zn铁氧体

摘要：以电炉粉尘（EAFD）中提取的Zn2+、铁鳞中提取的Fe3+和六水合氯化镍(NiCl2·6H2O)为原料,采用水热法直接制备合成尖晶石型Ni ZnFe2O4。首先探讨了焙烧温度、NaOH与EAFD质量比和焙烧时间对电炉粉尘中Zn2+提取率以及HCl浓度对铁鳞中Fe3+浸出率的影响,然后分析了Ni ZnFe2O4合成条件对其磁性能的影响。结果表明,当NaOH与EAFD质量比为1∶1,焙烧温度为450℃,焙烧时间为1h时,电炉粉尘中锌的提取率为88.77%;当HCl浓度为1.75mol/L时,铁鳞中Fe3+浸出率为96.89%。当EAFD中提取的Zn2+、铁鳞中提取的Fe3+和NiCl2·6H2O的摩尔比控制为1∶20∶9时,可以成功制备尖晶石型Ni-ZnFe2O4,并且对合成的Ni ZnFe2O4进行热处理之后可以显著提高其磁性能,当热处理温度从150℃提高到450℃时,尖晶石型Ni-ZnFe2O4的饱和磁感应强度从13.35（A·m2）/kg增长到40.06（A·m2）/kg。     

Study on Electronic Conductivity of CaO-SiO2-Al2O3-FeOx Slag System

Inthepast,becauseoflittleknowledgeoftheinfluenceofelectronictransportintheslag,researchworksaboutconductivityoftheslagweremainlyconcentratedonionicconductivity[1—15],so,thedataofelectronicconductivityarefew.Buttheworks[16—19]completedinrecentyearsshowedthatreactionofmetalmeltwithslagiscontrolledbytheconductionofelectronsintheslagundersomeconditions.Theprocessesthatarebeneficialtoelectronimmigratingthroughtheslagbulkandtheslag/metalfilminterfacewilldrasticallyincreasethereactionrateandtheexte…