Interfacial Reaction Between Solid Nickel and Liquid Zinc

Interfacial reactions between solid nickel and liquid zinc at 450-650 ℃ for 30-600 s were studied. The morphology and growth behavior of intermetallic compound layers at the interface between solid nickel and liquid zinc were observed and analyzed by SEM and EDS. The results show that γ and 8 phases are formed at 450 ℃ at the Ni/Zn interface, and at 550 ℃ and 650 ℃ only ）,phase is formed at the interthce and some δ phase particles will be participated during solidification on the surface of γphase layer. The β1 phase is absent under experimental conditions. Many cracks occur in the layers due to the difference in thermal expansion coefficients of these phases. It is found that the kinetics of the intermetallic compounds growth follows a parabolic law of time, as controlled by the diffusion mechanism. The apparent activation energies are 113.9 kJ/mol for the growth of γphase and 125.87 kJ/mol for γ1 phase, respectively.

Dissolution mechanism of solid nickel in liquid zinc saturated with Fe

The dissolution behavior of solid nickel in static liquid zinc saturated with Fe at 723 K was studied. The results show that when immersing solid Ni in liquid Zn saturated with Fe, the intermetallic compound layers consisted of γ and δ phases are formed on nickel substrate, which is the same as that in liquid pure zinc. However, some Γ2 particles are formed in the liquid near the solid/liquid interface. These Γ2 particles can easily heterogeneously nucleate on ζ particles and grow fast. The dissolution process is governed by diffusion of nickel atom across a concentration boundary layer in liquid Zn saturated with Fe, and is different from a mixed control mechanism of nickel in liquid pure zinc. The participation of Γ2 particles makes the dissolution of solid Ni in the liquid accelerated.

Highly efficient and selective photocatalytic dehydrogenation of benzyl alcohol for simultaneous hydrogen and benzaldehyde production over Ni-decorated Zn_(0.5)Cd_(0.5)S solid solution

Photocatalytic conversion of solar energy into hydrogen and high value-added fine chemicals has attracted increasing attention. Herein, we demonstrate an efficient photocatalytic system for simultaneous hydrogen evolution and benzaldehyde production by dehydrogenation of benzyl alcohol over Nidecorated Zn_(0.5)Cd_(0.5)S solid solution under visible light. The photocatalytic system shows an excellent hydrogen production rate of 666.3 μmol h^(-1) with high stability. The optimal apparent quantum yield of52.5% is obtained at 420 nm. This noble-metal-free photocatalytic system displays much higher activity than pure Zn_(0.5)Cd_(0.5)S and Pt-loaded Zn_(0.5)Cd_(0.5)S solid solution. Further studies reveal that the metallic Ni nanocrystals play an important role in accelerating the separation of photogenerated charge carriers and the subsequent cleavage of α-C–H bond during dehydrogenation of benzyl alcohol.

Recovery of valuable metals from anode material of hydrogen-nickel battery

Simultaneous recovery of rare earth,nickel and cobalt resources from the anode material of hydrogen-nickel battery was performed through a hydrometallurgical process. Most of rare earth elements are separated from nickel and cobalt in the form of sulfates when the anode material is firstly leached with sulfuric acid. Then,the precipitated rare earth sulfates are dissolved with sodium hydroxide to form rare earth hydroxides. The rare earth element,zinc and manganese ions in the lixivium are also separated from nickel and cobalt by using PC-88A extractant system,and the organic phase loaded rare earth is stripped with hydrochloric acid. By neutralizing the stripping solution with rare earth hydroxide,the rare earth chloride is obtained. Under the suitable leaching conditions of sulfuric acid 3 mol/L,leaching time 4 h and temperature 95 ℃,94.5% of rare earth in the anode material is transformed into the sulfate precipitates,and the leaching ratios of nickel and cobalt can approach 99.5%. When the pH value of the extractive system is controlled in the range of 3.0-3.5,the rare earth elements in the lixivium can be extracted completely into the organic phase,and the stripping recovery of the rare earth can reach 98% in the extraction stage. The total recoveries of rare earth,nickel and cobalt are 98.9%,98.4% and 98.5%,respectively.

Topography,structure,and formation kinetic mechanism of carbon deposited onto nickel in the temperature range from 400 to 850°C

The carbon deposition behavior on nickel particles was observed within the temperature range from 400 to 800°C in a pure methane atmosphere. The topography, properties, and molecular structure of the deposited carbon were investigated using field-emission scanning electron microscopy (FESEM), temperature-programmed oxidation (TPO) technology, X-ray diffraction (XRD), and Raman spectroscopy. The deposited carbon is present in the form of a film at 400-450°C, as fibers at 500-600°C, and as particles at 650-800°C. In addition, the structure of the deposited carbon becomes more ordered at higher temperatures because both the TPO peak temperature of deposited carbon and the Raman shift of the G band increase with the increase in experimental temperature, whereas the intensity ratio between the D bands and the G band decreases. An interesting observation is that the carbon deposition rate is suppressed in the medium-temperature range (M-T range) and the corresponding kinetic mechanism changes. Correspondingly, the FWHM of the G and D1 bands in the Raman spectrum reaches a maximum and the intensities of the D2, D3, and D4 bands decrease to low limits in the M-T range. These results indicate that carbon structure parameters exhibit two different tendencies with respect to varying temperature. Both of the two group parameters change dramatically as a peak function with increasing reaction temperature within the M-T range.

Immobilization of His-Tagged Proteins on Various Solid Surfaces Using NTA-Modified Chitosan

Continued advancement of protein array, bioelectrode, and biosensor technologies will necessitate development of methods that allow for increased protein immobilization capacity and more control over protein orientation. Toward these ends, we developed a method involving modification of chitosan with nitrilotriacetic acid (NTA) to achieve immobilization of a larger amount of His-tagged protein than is possible with current methods. The immobilization capacity of our method was evaluated using His-tagged GFP (Green Fluorescent Protein) as a model protein. The average immobilization density on modified glass was about 32 ng/mm2. Our method is suitable for use on a variety of solid surfaces, including glassy carbon, silicon wafers, polycarbonate, and beaten gold.

Synthesis and Electrochemical Property of Calcium Doped LiNi0.8Co0.2O2 Solid Solution

A divalent ion doped LiNi0.8Co0.2O2 solid solution, LiNi0.79Co0.20Ca0.01O2, was synthesized in air at 720℃. The structure and electrochemical property as cathode material of lithium ion batteries were measured by XRD and charge-discharge system. The solid solution showed high capacity and good cycle-ability. The second discharged capacity reached 190 mAh穏-1 at the current density of 100 mA穏-1.

Cup-drawing formation of steel sheet with nickel coating by finite element method

The finite element method(FEM) simulation of deep-drawing of steel sheet with nickel coating based on the solid element and dynamic explicit method was reported. Penalty function method was used to treat the contact algorithm. The friction between the punch and coating sheet was based on a Coulomb formulation. The combination of coating and substrate was defined as tied with failure contact. The results of the simulation illustrate that the steel sheet and the nickel coating do not delaminate at the interface. The stress field of the nickel coating is more complicated than that of the steel substrate. Furthermore,it is found that the punch-nose radius is the most unsubstantial part for the intensity of the entire deep-drawing part and the thinnest part,it is a dangerous zone for the break. At this zone,the thickness thinning of the steel sheet and the nickel coating are up to 4.8% and 6.7%,respectively. Meanwhile,it is found that the curve of the variable blankholder force(VBHF) designed can improve the formability of sheet.

Carbon dioxide catalytic conversion to nano carbon material on the iron–nickel catalysts using CVD-IP method

The over-consumption of fossil fuels resulted in the large quantity emission of carbon dioxide （CO2）, which was the main reason for the climate change and more extreme weathers. Hence, it is extremely pressing to ex- plore efficient and sustainable approaches for the carbon-neutral pathway of CO2 utilization and recycling. In our recent works with this context, we developed successfully a novel ＂chemical vapor deposition integrated process （CVD-IP）＂ technology to converting robustly CO2 into the value-added solid-form carbon materials, The monometallic FeNi0-Al2O3 （FNi0） and bimetallic FeNix-Al2O3 （FNi2, FNi4, FNi8 and FNi20） samples were synthesized and effective for this new approach. The catalyst labeled FNi8 gave the better performance, exhibited the single pass solid carbon yield of 30%. These results illustrated alternative promising cases for the CO2 capture utilization storage （CCUS）, by means of the CO2 catalytic conversion into the solid-form nano carbon materials.

镀镍FeS对铁基轴承材料摩擦磨损性能的影响

以Fe,C混合粉末为原料,FeS或镀镍FeS为固体润滑剂,通过粉末冶金工艺制备了FeS/铁基轴承材料的试样,研究镀镍FeS对试样显微组织、密度、硬度和摩擦磨损性能的影响,结果表明:FeS表面镀镍提高了FeS与基体的界面结合强度,增大了试样的密度和硬度;干摩擦条件下,含镀镍FeS试样摩擦表面形成的固体润滑膜更牢固、完整,黏着磨损减少,耐磨性提高;油润滑条件下,润滑油膜与FeS固体润滑膜可以协同润滑,提高了摩擦副间润滑膜的稳定性和承载能力,减摩耐磨性能更好。

二次固溶加时效对K4648镍基高温合金组织与性能的影响

采用扫描电镜、能谱仪和拉伸试验等研究了二次固溶加时效对K4648镍基高温合金组织与性能的影响。结果表明:二次固溶加时效处理后,合金中析出了尺寸更大的针状α相,M_(23)C_(6)碳化物的尺寸变小;随着二次固溶温度的升高,针状α相逐渐粗化,M_(23)C_(6)数量增多且大部分在晶界处连续分布。经过二次固溶加时效处理,合金抗拉强度显著提高,塑性略有下降。K4648合金的最佳二次固溶温度为1200℃,此时合金的抗拉强度达到810 MPa,相比一次固溶加时效提高了约39%,伸长率略微下降,从17.2%降为15.3%。

高球形度超高镍三元前驱体合成因素的研究

探讨不同的搅拌频率、不同的固含量对三元前驱体合成因素的影响,通过共沉淀反应过程中梯次降低搅拌频率和调控反应过程中浆料的固含量,制备了高球形度、高振实密度、粒度分布适中的超高镍三元前驱体Ni_(0.95)Co_(0.04)Mn_(0.01)(OH)_(2)。结果表明:以38 Hz开机,然后以每12 h下调3 Hz的速度梯次降低搅拌频率至20 Hz,并且将固含量控制在300 g/L,既可以保证高球形度、高振实密度,减少球粘连,又可以避免前驱体产生裂纹和碎球,制备出了高球形度、颗粒分布均匀的超高镍三元前驱体。

镍渣—全尾砂混合骨料配比试验研究

为实现固废循环利用,降低尾砂和镍渣的固废堆存,开展了镍渣—全尾砂混合骨料配比试验。通过扫描电镜和X射线荧光光谱测定(XRF)方法分析了镍渣和全尾砂的粒级分布和化学成分,利用骨料堆积密实度理论确定了镍渣—尾砂的配比优化范围为4∶6、5∶5和6∶4;考虑料浆的流动性、和易性及充填体强度,最终推荐镍渣—全尾砂的最优配合比为5∶5,料浆的质量浓度为77%~79%,水泥添加量为310 kg/m^(3);针对镍渣—全尾砂充填,镍渣利用量最高不超过50%,最大质量浓度为79%,对应的剪切应力为112.634 Pa,黏度为0.938 Pa·s。

不同固溶处理工艺对N08120镍合金性能的影响

研究了1110~1190℃固溶处理工艺对N08120镍合金钢板的力学性能和组织的影响。结果表明:随着固溶处理温度的提高,合金的塑性和表面耐蚀性变好;在1190℃下,随着固溶时间的增加,合金的塑性和表面耐蚀性先变好再变差。

三元镍钴锰酸锂的制备、电化学反应和研究进展

化石能源广泛地使用,在全球范围内造成了广泛的环境问题,开发新能源技术已经十分紧迫。循环使用的化学电源是能将电能和化学能进行相互转换。锂离子电池是依靠锂离子在电源正负极之间转移实现充放电过程,因工作电压高,电池体积小,电池质量轻,电池能量密度高,循环寿命长,因而受到广泛的关注。锂离子电池正极材料的制备工艺包括高温固相法,溶胶凝胶法,水热法和溶剂热法等。镍钴锰三元化合物材料存在的问题包括阳离子混排,不可逆相变和热失控等,解决的方法包括材料结构形貌的有效控制,掺杂和修饰改性。镍钴锰三元化合物材料用在锂离子正极材料时,其充放电过程与钴酸锂类似。目前LiNi_(1/3)Co_(1/3)Mn_(1/3)O_(2)已经运用到圆柱电池和动力电池上,部分代替钴酸锂等材料。目前三元化合物具有非常广阔的应用前景。

固溶处理对K423A合金显微组织与力学性能的影响

研究了固溶处理对K423A合金组织以及力学性能的影响。采用热力学计算软件JMatPro对K423A合金中相的稳定性及体积百分比进行计算。借助扫描电镜对铸态以及固溶态合金进行显微组织观察,使用扫描电镜附带的能谱仪对铸态以及固溶态合金的显微组织进行成分分析。碳化物与γ′相的尺寸以及体积分数使用Image-Pro Plus软件进行统计分析。对铸态以及固溶态的合金进行室温拉伸、850℃/325 MPa持久以及室温硬度测试。结果表明:固溶后γ′相呈不规则的形貌,弥散的分布在γ基体中。固溶态合金中碳化物的形态发生变化,由原来的多数长条状逐渐变为以块状为主,碳化物尺寸变得细小。铸态与固溶态具有相同的抗拉强度,铸态的屈服强度更高,但伸长率偏低。在850℃/325 MPa条件下,铸态合金具有较高的持久寿命,固溶态合金有更好的塑性。

有色矿冶产品固体废物属性鉴别方法

有色矿冶产品固体废物鉴别的关键在于判断物料的生产来源,常规的鉴别手段一般要求联合使用多台大型设备。以镍锍化矿石及粗制氧化锌为例,利用Maps Mineralogy矿物分析方法分析了试样的固体废物属性,并与基于成分分析和物相分析的常规检测方法进行了对比。结果表明:Maps Mineralogy矿物分析方法可以更直观地判断试样的来源及加工工艺,在固体废物属性判别领域有着较好的应用前景。

Ni-Cr合金真空钎焊金刚石界面反应的热力学与动力学分析

采用Ni-Cr合金钎料 ,适当控制钎焊工艺 ,实现了金刚石与钢基体的高强度连接。采用扫描电子显微镜 (SEM)和能谱仪 (EDS)及X射线衍射结构分析了真空加热条件下 ,Ni-Cr合金钎料与金刚石之间的界面反应 ,探讨了钎料与金刚石界面处碳化物的形成机理。结果表明 ,Ni-Cr合金钎料中的Cr和少量Si在金刚石表面富集并与金刚石中的C发生反应生成Cr7C3 、Cr3 C2 碳化物 ,其中Cr7C3 呈笋状生长 ,Cr3 C2 呈片状 ,可能有少量SiC生成。金刚石与钎料的界面形成了金刚石 \SiC \Cr3 C2 \Cr7C3 钎料的梯度材料 ,实现了Ni-Cr合金与金刚石的冶金结合。

NiO-MgO固溶体的形成对Ni/MgO-AN催化CO_2重整CH_4反应活性和稳定性的影响

以在流动N2中热处理的Mg(OH)2醇凝胶制得的纳米氧化镁(MgO-AN)为载体,浸渍Ni(NO3)2后经不同温度焙烧得到Ni含量为8.8%的NiO/MgO样品,还原后制得Ni/MgO-AN催化剂.采用XRD和TPR技术对NiO和MgO之间形成的NiO-MgO固溶体进行了表征,并将Ni/MgO-AN催化剂用于催化CO2重整CH4反应.结果表明,在低于650℃焙烧时,NiO不能完全溶入MgO中,NiO/MgO样品中存在自由的NiO粒子,还原态Ni/MgO-AN催化剂在CO2重整CH4反应中的稳定性低;当样品焙烧温度等于或高于650℃时,NiO可以完全溶入MgO中形成NiO-MgO固溶体,还原态Ni/MgO-AN催化剂具有高稳定性.

2-(2-喹啉偶氮)-5-二乙氨基苯甲酸固相萃取光度法测定环境水样中的镍

用 2 (2 喹啉偶氮 ) 5 二乙氨基苯甲酸 (QADEAB)与镍的显色反应及WatersPorapak Sep Park固相萃取小柱对显色络合物的固相萃取 ,建立了测定水样中 μg/L级镍的新方法。水样中的镍在pH =8.0的硼酸 磷酸二氢钾缓冲介质中和Tween 80存在下与QADEAB反应生成 2∶1稳定有色络合物 ,该络合物可用WatersPorapak Sep Park固相萃取小柱富集 ,用乙醇洗脱后用光度法测定 ,可测定水样中 μg/L级的镍。方法用于几种环境水样分析 。