Extraction of vanadium and synthesis of vanadium pentaoxide from Bayer’s sludge

Wastes generated from the Bayer’s process serve as valuable resources for aluminum, vanadium, gallium, etc. This work aims to develop a environmentally acceptable and low-cost chemical leaching-cumpurification method for the recovery of vanadium sludge of Indian alumina plant (10–12% V₂O₅) and synthesize vanadium pentaoxide. The efficiency of leaching was evaluated by various lixiviants like acidified water, H₂SO₄, soda and NaOH against variation in pulp density and temperature. Maximum extraction (96%) vanadium was achieved using acidified water leaching at above ambient temperature in 1 h with 200 g/L pulp density following diffusion control model. Finally, the vanadium rich leach liquor was purified by steps of adsorption/precipitation etc., to remove with iron and silica to get vanadium pentaoxide. A high purity product of 99% V₂O₅ was obtained by allowing the adsorption at acidic pH followed by desorption and precipitation at 90°C.     

Dunhuang growing into a vanadium base in Gansu Province

The city of Dunhuang is the only vanadium production area in Gansu Province.In 2006,the output of vanadium exceeded 2000 tons for the first time,giving Dunhuang the fame of vanadium base in Gansu Province.     

High temperature mechanical properties of vanadium alloyed γ base titanium-aluminides

High temperature mechanical properties of vanadium alloyed γ base Ti aluminides have been related to the microstructure. The microstructures were controlled by chemistry modification—vanadium alloying between 5.3 and 12.7 mol.% for phase distribution control—and isothermal forging. The properties were evaluated using tensile tests at strain rates between 3 × 10⁻⁴s⁻¹ and at temperatures between 1070 and 1420 K. The γ plus β phase intermetallic exhibited excellent hot workability with an elongation more than 600% and an m-value of 0.8. The mechanism of the superplastic deformation was critically discussed.     

Microstructure of A γ−α2−β TiAl alloy containing iron and vanadium

Ordered ß-phase (B2 CsCl structure) has been identified in a Ti-45.5 at.% Al-1.6 at.% Fe-1.1 at.% V-0.7 at.% B alloy being developed for high temperature applications. Selected area electron diffraction has been used to identify the orientation relationships and interface planes of the ß-phase with the bulk γ-TiAl and α₂-Ti₃Al phases. Energy dispersive X-ray spectroscopy indicates that the ß-phase has approximately the same Ti/Al ratio as the α₂-Ti₃Al phase, and is stabilized within the microstructure by Fe and V. Channeling enhanced microanalysis studied (ALCHEMI) show that the Fe and V both occupy the same sublattice as the Al atoms in the cubic ß-phase structure, and that Fe occupies the Al sites in the γ-phase. Fe and V are concentrated in the ß-phase, which effectively getters these dopants from the γ and α₂ phases. Titanium ferride precipitates, probably FeTi, have been observed within the ß-phase.     

Ce–Ti catalysts modified with copper and vanadium to effectively remove slip NH3 and NOx from coal-fired plants

In this work, V/Ce–Ti catalysts were modified with different kinds of transition metals (Cu, Fe, Co, Mn) by sol–gel and impregnation methods. The NH₃ oxidation performance of them was tested to select the most active catalyst in NH₃-selective catalytic oxidation (NH₃–SCO). The effect of NO, SO₂ and H₂O was also investigated. The experimental results indicate that 1% Cu–V/Ce–Ti catalyst exhibits the most significant ability to remove slip ammonia discharged from coal-fired plants and its NH₃ conversion efficiency reaches 90% at 300 °C. In addition, 97% NO_x can be removed when NO is introduced in the gas. Cu–V/Ce–Ti catalyst also obtains good resistance to H₂O and SO₂. Based on the characterization experiment, the introduced Cu and V are highly dispersed on Ce–Ti catalyst and they can increase the redox properties and the number of acidic sites. Besides, the redox cycles among Cu, V and Ce species on Cu–V/Ce–Ti catalyst surface are conducive to generating more active oxygen and promoting the oxidation capacity of the catalyst.     

纯铜中铋,锑,砷,铁,镍,铅,锡,锌的光谱定量分析

本文介绍了一种光谱定量分析方法。该方法使用ＢＹＧ０１－１氧化铜光谱标准样品，对１－４号纯铜中铋、锑、砷、铁、镍、铅、锡、锌８个杂质元素进行定量分析。分析方法简单，测定结果与化学结果基本相符。方法的测定下限为３×１０￣（０６）。     

铂饰品中Pt, Pd, Au, Ag, Cu, Ni, Zn, Fe的测定

试验研究建立了同一试料溶液连续、同时测定铂饰品中各成分的分析方法。主体Pt以氯铂酸铵称量法及火焰原子吸收光谱(FAAS)法或电感耦合等离子发射光谱(ICP-AES)法测定滤液中残留Pt进行补差而测定。主成分Pd,Au,Ag,Cu和焊料成分Ni,Zn,Fe以FAAS法或ICP-AES法测定。其方法回收率分别为:Pt99.9%~100%;Pd99.3%~99.7%;Au99.5%~l01.5%;Ag98.0%~100%;Cu97.7%~99.3%;Zn98.0%~99.0%;Ni94.0%~105%;Fe95.0%~99.0%。实际试样分析时,各成分质量分数之和一般在99.12%~l01.2%之间,接近于100%,间接说明方法的可靠性。本法适用于Pt-Pd二元体系和Pt-Pd-Au-Cu多元复杂体系的铂饰品的破坏分析,可用于校正X荧光光谱法无损检测铂饰品的分析结果。     

X射线荧光光谱法测定烧结矿中Fe,Al,Ca,Mg,Si,S,Mn,P

烧结矿是高炉冶炼的重要原料之一 ,准确快速分析烧结矿中主、次量元素 ,对于指导烧结矿及高炉生产具有重要意义。由于烧结矿日常分析元素较多 ,采用化学分析方法 ,分析时间长 ,手续繁琐。本文利用多道同步Ｘ射线荧光光谱仪 ,合理选择分析及制样条件 ,对烧结矿中主、次量元素进行分析。结果表明 :该法分析速度快、准确度高 ,完全满足日常分析的要求。1　实验部分1 1　仪器及工作条件Ｓｉｍｕｌｔｉｘ 1 1型Ｘ射线荧光光谱仪 (日本理学 ) ,盘式振动磨 (ＷＣ材质 ) ,5 0ｔ油压机。工作条件 :Ｘ光管 ( 4 0ｋＶ - 2 5ｍＡ) ,Ｐ1 0气体流量 2 5ｍ…     

ICP-AES法测定铍铜合金中Be, Ni, Ti, Co, Fe, Al, Si, Mg和Pb

通过操作条件的试验研究，用基体匹配法校正基体干扰，并选择了最佳工作条件。样品加标回收率为96％～110％，方法快速、简便、可靠，适用于铍铜合金的快速检验。     

FAAS法测定铝合金中Fe,Cu,Zn,Mn,Ni,Ca,Mg和Cr

铝合金的分析一般采用化学法、光谱法[1],部分元素的测定也有采用火焰原子吸收法的报导““,化学法操作繁琐,周期长,技术条件严格,而且所用的试剂量大．本文采用火焰原子吸收法连续测定了铝合金中铁、铜、锌、锰、镍、钙、镁和铬．方法操作简单、准确、稳定．1实验部分1．1主要仪器和试剂PE3030B原子吸收光谱仪．氯化钢溶液（lap／L）：称取259LaP。,溶于80rnL盐酸中,用去离子水稀释至250InL;铁、铜、锌、锰、镍、钙、镁、铬标准溶液：浓度均为IIDg／mL。仪器工作条件见表l．1．2分析步骤称取1．00009样品于250mL烧杯中,加人…     

电感耦合等离子体原子发射光谱法测定铁矿石中Si,Ca,Mg,Mn,Al,P,V,Ti

铁矿石中Si O2,CaO,MgO,MnO,Al2O3,P,V2O5,Ti O2,通常用分光光度法或容量法分别测定,方法繁琐费时。用电感耦合等离子体光谱仪测定铁矿石的主体成分,方便快捷,准确性好,无明显的化学干扰。通过研究对比,选择无明显干扰的两条或一条谱线,使选择的波长符合在同一溶液中能同时测定其它组分的要求;同时采用与试样组分相近的标准样品绘制工作曲线,用标准样品进行对照,ICP-AES法测定铁矿石中上述组分,结果令人满意。1实验部分1·1主要仪器及工作条件IRIS IntrepidⅡ型垂直全谱直读等离子光谱仪(美国Thermo公司):固体检测器(CID),波长…     

FAAS法测定磷矿粉中微量Fe,Co,Ni,Cu,Pb,Zn

用火焰原子吸收光谱法对新疆某地的磷矿粉中Fe ,Co ,Ni,Cu ,Pb ,Zn微量元素进行了分析测定 ,并探讨了酸度、干扰离子等对测定的影响。所拟方法快速、简便 ,分析结果十分满意     

X射线荧光光谱仪测定铝合金中Si,Mn,Fe,Cr,Ni,Ti,Cu

采用改造后的VXQ -15 0AX射线荧光光谱仪和日本岛津公司提供的数据软件 ,合理选择分析条件 ,对铝合金中Si,Mn ,Fe ,Cr,Ni,Ti,Cu元素进行测定 ,结果较为满意。