Advances on Rare Earth Application in Pollution Ecology

RE application in the agriculture was originatedfrom China and entitled to exclusive intellectual prop erty, which is the most advanced technology of thisfield in the world. Agriculture and RE industry of Chi na have been greatly benefited from t…     

稀土对低温固体B-C-N共渗的影响

本文研究了硼－碳－氮－稀土（Ｂ－Ｃ－Ｎ－ＲＥ）共渗工艺及共渗层的组织性能，并与硼－碳－氮（Ｂ－Ｃ－Ｎ）共渗工艺及共渗层的组织性能进行了比较，结果表明，在适当范围内，稀土具有明显的催渗作用；与Ｂ－Ｃ－Ｎ共渗相比，Ｂ－Ｃ－Ｎ－ＲＥ共渗层的耐磨性和耐蚀性明显提高。本文对Ｂ－Ｃ－Ｎ－ＲＥ共渗的机理及稀土元素的作用作了初步的探讨。     

Effect of Rare Earth Elements on Powder Boro-Carbo-Nitriding at Low Temperature

Ｂｏｒｉｄｉｎｇｃａｎｓｉｇｎｉｆｉｃａｎｔｌｙｉｍｐｒｏｖｅｓｕｒｆａｃｅｐｒｏｐｅｒｔｉｅｓｏｆｓｔｅｅｌｓ,ａｎｄｔｈｕｓｉｓａｐｒｏｓｐｅｒｏｕｓｓｕｒｆａｃｅｓｔｒｅｎｇｔｈｅｎｉｎｇｐｒｏｃｅｓｓｗｈｉｃｈｈａｓａｌ ｒｅａｄｙｂｅｅｎｕｓｅｄｉｎｔｒｅａｔｉｎｇｓｏｍｅｄｉｅｓａｎｄｃｕｔ ｔｉｎｇｔｏｏｌｓ[1 ] .Ｈｏｗｅｖｅｒ,ｔｈｅｒｅｅｘｉｓｔｓｏｍｅｐｒｏｂ ｌｅｍｓｉｎｂｏｒｉｄｉｎｇ .Ｆｉｒｓｔｌｙ ,ｂｏｒｉｄｉｎｇｉｓｇｅｎｅｒａｌｌｙｐｅｒｆｏｒｍｅｄａｔｔｅｍｐｅｒａ…     

Effect of Rare Earth Elements on Quenching Crack Resistance of Steel 9Cr2Mo

Ｒｏｌｌｅｒｆｏｒｃｏｌｄｒｏｌｌｉｎｇｉｓａｋｅｙｆｏｒｇｉｎｇｐａｒｔ,ｗｈｉｃｈｅｘｐｅｒｉｅｎｃｅｓｃｏｎｔａｃｔｓｔｒｅｓｓ ,ａｌｔｅｒ ｎａｔｉｎｇｓｔｒｅｓｓａｎｄｆｒｉｃｔｉｏｎａｌｓｔｒｅｓｓｄｕｒｉｎｇｒｏｌｌｉｎｇ .Ｔｈｅｒｅｆｏｒｅ ,ｈｉｇｈｅｒｓｔｒｅｎｇｔｈ ,ｓｕｒｆａｃｅｈａｒｄｎｅｓｓ,ｗｅａｒｒｅｓｉｓｔａｎｃｅａｎｄｅｎｏｕｇｈｔｏｕｇｈ ｎｅｓｓｓｈｏｕｌｄｂｅｃｏｎｓｉｄｅｒｅｄｆｏｒｍａｎｕｆａｃｔｕｒｉｎｇｔｈｉｓｃｏｌｄｒｏｌｌｅｒ[1] .Ｓｉｎｃｅｔｈｅ…     

Primary Results of New Rare Earth Materials for Hongti Grape

New rare earth (RE) materials including RE phosphate as base fertilizer, bioactive RE micro-fertilizer and RE entire plant nutrition agent as topdressing fertilizer are treated on Hongti grope.The result showes that the plant leaves become thicker, the color is dark green, the plant disease index is lower, and the sugar content significantly increases.     

Research and Development of Rare Earth Advanced Materials in China

ＲｅｓｅａｒｃｈａｎｄＤｅｖｅｌｏｐｍｅｎｔｏｆＲａｒｅＥａｒｔｈＡｄｖａｎｃｅｄＭａｔｅｒｉａｌｓｉｎＣｈｉｎａＷａｎｇＤｉａｎｚｕｏ（王淀佐），ＷａｎＱｕｎ（万群），ＹａｎｇＹｕｃｈｕｎ（杨遇春）（ＧｅｎｅｒａｌＲｅｓｅａｒｃｈＩｎｓｔｉｔｕｔｅ...     

Effect of Rare Earth on Thermal Shock Resistance of Steel 9Cr2Mo

Ｒａｒｅｅａｒｔｈｅｌｅｍｅｎｔｓｈａｖｅｂｅｅｎａｄｄｅｄｉｎｔｏｈｏｔｒｏｌｌｅｒｓｔｅｅｌ.ＲＥｅｌｅｍｅｎｔｓｃａｎｉｍｐｒｏｖｅｔｈｅｒ ｍａｌｆａｔｉｇｕｅ[1] ,ｌｏｗｆｒｅｑｕｅｎｃｙｆａｔｉｇｕｅ[2 ] ,ｐｌａｓ ｔｉｃｉｔｙａｎｄｔｏｕｇｈｎｅｓｓ[3] ,ｒｅｆｉｎｅａｕｓｔｅｎｉｔｉｃｇｒａｉｎｓｉｚｅ[4] ａｎｄｍｏｄｉｆｙｉｎｃｌｕｓｉｏｎｓ[5 ] ｏｆｈｏｔｒｏｌｌｅｒｓｔｅｅｌ 6 0ＣｒＭｎＭｏ .Ｓｔｅｅｌ 9Ｃｒ2Ｍｏｉｓａｔｒａｄｉｔｉｏｎａｌｃｏｌｄｒｏｌｌｅｒｓｔｅｅｌ.Ｗｈｅｎ…     

Effects of rare earth on inclusions and corrosion resistance of 10PCuRE weathering steel

The types,morphologies and distributions of nonmetallic inclusions in Cu-P weathering steels with and without rare earth were analyzed through a quantitative image analyzer,scanning electron microscopy(SEM)and energy dispersive spectroscopy(EDS)attached to SEM.Solid-soluble content of rare earth in the steels was analyzed by non-aqua electroanalysis and ICP.The results showed that rare earth modified the types and the morphologies of inclusions in the weathering steels.The small spherical rare earth oxysulfides and rare earth sulphides replaced the elongated MnS inclusions in the RE weathering steels.The rare earth inclusions dispersedly distributed and most inclusions were smaller than 2 μm in size.The optimum content of RE was 0.0065%-0.016% for 10PCuRE weathering steels containing about0.002% oxygen and 0.004% sulfur.Solid-soluble content of rare earth in steels was(14-20)x 10-6,which can act as a micro-alloying element.The corrosion resistance of 10PCuRE weathering steels and Q235 were studied by dry-wet cyclic immersion test.Their corrosion rates were obtained respectively.The polarization curves and pitting corrosion behaviors of weathering steels with and without rare earth were measured by electrochemical methods.The corrosion resistance of Cu-P weathering steels was improved by adding an appropriate amount of rare earth.Less and fewer rare earth inclusions largely decreased pitting susceptibility and rate of pit propagation.The pitting potential and the resistance against pitting corrosion of the RE weathering steel were significantly improved due to the modification of rare earth to inclusions.     

稀土对铁基自熔合金喷焊层组织与耐蚀性能的影响

通过熔炼—雾化工艺制备了稀土铁基自熔合金粉末,并考察了稀土对铁基自熔合金喷焊层的显微组织及其在弱酸、中性盐溶液中耐蚀性能的影响。采用金相显微镜、SEM、EDAX对合金喷焊层的物相结构、显微组织进行了观察和分析。在实验结果的基础上,对稀土的有关作用机制进行了分析和讨论。     

稀土超量积累植物铁芒萁中稀土元素的赋存状态

从稀土矿区和非矿区采集的稀土超量积累植物铁芒萁的叶片分离成醚溶物、水溶物、碱溶物和残余物四个组分。用中子活化分析测定了其中稀土元素的含量 ,发现稀土元素主要存在于残余物 (果胶、半纤维素、纤维素 )中 ,而主要成份为蛋白的碱溶物中稀土含量维持较低水平 ,从而避免了大量稀土对植物正常生理功能造成影响。矿区幼叶醚溶物 (脂肪、色素、蜡等 )和碱溶物中稀土含量明显高于矿区和非矿区的成熟叶片 ,表明稀土元素很可能参与了植物的生理活动。     

Tensile Properties of Surface-Treated Glass Fiber Reinforced PTFE Composite with Rare Earth Elements

The optimum amount of rare earth elements (RE) for treating glass fiber surface and its effect on the tensile properties of glass fiber reinforced polytetrafluoroethylene (GF/PTFE) composites were investigated. The tensile properties of GF/PTFE composites with different surface treatment conditions were measured. The fracture surface morphologies were observed and analyzed by SEM. The results indicate that rare earth elements can effectively promote the interfacial adhesion between the glass fiber and PTFE, owing to the effects of rare earth elements on the compatibility. The tensile properties of GF/PTFE composites can be improved considerably when the content of RE in surface modifier is 0.2%-0.4%,and the optimum performance of GF/PTFE composites is obtained at 0.3 % RE content.     

Progress of Study on Application of Rare Earth Metals in Steels

With the improvement of the clean steel by degrees, the functions of rare earth metals in steel are more focused on modification of inclusions and micro alloying.The new study concerning the application of RE metals in clean steels were investigated by ICP, metallographic examination, SEM, EDS, EPMA, TEM and IMMA.The mechanism of corrosion resistance in the weather resistance steel was clarified.The mechanism of abrasion resistance and the life of fatigue enhanced in the RE - heavy rails steel were discussed.Progress in study of application of rare earth metals in steels (including weather resistance steel, low alloy steel, and heavy rails steel) was covered in this paper.     

Kinetics of Formation of Large-Dimension Rare Earth Inclusion in Steels

The elemental distribution within the large-dimension rare earth inclusion in steels was studied through analysis on plane distribution of elements by EPMA (Electron Probe Microanalyzer). The kinetics and mechanism of formation of RE inclusion were discussed, taking 5CrNiMo steel with the addition of RE and other microalloying elements as example. RE inclusions nucleate on oxides and sulphides with high melting point and grow up separately, then integrated by relatively high surface activity, which is a particular characteristic of RE elements, in liquid phase and during the course of solidification. Finally, the fine and dispersed RE inclusions merge and grow into a large-dimension one.     

Economical and Technical Indices of Decomposition Processes of Typical Rare Earth Minerals in China

The typical treatment processes we of main rare earth resources in China, especially the economical and technical indices of the minerals decomposition of such as ionic adsorptive rare earth deposit ore, bastnasite and mixed with monazite in Baotou, was presented. The dispersive ionic adsorptive rare earth deposit ore, which is enriched on valuable middle and heavy elements, concentrated by bicarbonate precipitation after exchanging with ammonium sulphate solution. Planting and waste liquid should be focused. Bastnasite and/or monazite, which is enriched light rare earth, centralized with high content and capacity,concentrated by gravimetric, magnetic, floating, then decomposed by calcinations and leaching. Waste liquid, gases and dregs should be treated properly. Investors interested in RE industry can find out the technical and economic characters and history of various RE minerals. Engineers and workers in RE industry can also find the differences of the plants, so as to make more efforts on improving management. However, solving environment protection problems for each process should be committed extraordinarily in order to make a sustainable development of RE industry.     

稀土铁基自熔基合金抗硫化氢腐蚀性能的实验研究

近年来关于稀土在热喷涂（焊）材料中的应用研究正日益受到人们的重视。铁基自熔合金末作为一种广泛使用的热喷涂（焊）材料具有价格低廉，喷涂（焊）层的耐磨性较好等优点，但其耐蚀性较差。为此，本研究引入稀土对其改性。通过熔炼－雾化工艺制备了稀土铁基自熔合金粉末，并考察了稀土对铁基自熔合金喷焊层在硫化氢介质中气蚀和在含硫化氢的中性氯化钠溶液中浸蚀的影响。结果表明，铁基自熔合金（含稀土和不含稀土）喷焊层试样表现出较强的抗硫化氢能力。铁基合金喷焊层试样在含硫化氢的4Wt%NaCl溶液中的腐蚀速率随稀土的添加量增加量增加而逐渐降低，且稀土添加量有最佳值0.2Wt%。     

高丰度稀土永磁材料的研究现状与展望

随着稀土永磁材料应用领域的扩大及需求量的猛增,导致关键稀土元素(Pr、Nd、Dy、Tb)的过度使用,而高丰度稀土元素(La、Ce、Y)却不断积压.高丰度稀土永磁材料不仅可以降低成本,还可实现稀土资源综合平衡利用,出于国家战略安全和原材料成本角度考虑,高性价比的高丰度稀土永磁材料的研究与开发势在必行.近年来,大量学者对高丰度稀土永磁材料的高值化利用展开了广泛研究.然而,在不同成分合金中,其主相热稳定性、第二相种类、相析出行为、价态、微量元素的偏聚冶金行为等方面均与目前广泛使用的Nd基商业磁体存在较大差异.综述了高丰度稀土永磁材料的相结构、磁性能、微观结构和耐蚀性能等研究现状,并为其进一步开发与利用提出了建议.      

Modification Mechanism of Rare Earth Elements in ZA27 Casting Alloys

The model of the liquid-phase ZA27 alloys was set up by molecular dynamics theory. The atomic structure of phase, RE-compounds, and the phase-liquid interface in ZA27 alloys were constructed by computer programming. Electronic structures of phase with rare earth elements dissolved and of phase-liquid interfaces with rare earth elements enrichment in ZA27 casting alloys were investigated by using the Recursion method. The ESE energy of RE elements and the structure energy of RE-compounds, phase, and the liquid-phase ZA27 alloys were calculated. The results show that rare earth elements are more stable to be in the phase interface than in phase, which explains the fact of very small solid solubility of rare earth elements in phase, and the enrichment in the solid-liquid growth front. This makes dendrite melt and break down, dissociate and propagate. RE-compounds can act as heterogeneous nuclei for phase, leading to phase refinement. All above elucidates the modification mechanism of rare earth elements in zinc-aluminum casting alloys, at electronic level.     

2,4-二氯-6-溴偶氮氟膦与稀土的显色反应及其应用

摘 要：对显色剂2,4-二氯-6-溴偶氮氟膦与稀土元素在微波催化下的显色反应进行了研究。在硝酸及少量吡啶介质中,于40℃的微波水浴中加热催化8 min,试剂与各稀土发生显色反应,形成稳定的蓝色配合物。典型稀土元素La、Ce与显色剂的配合比均为1︰3,各稀土配合物的最大吸收波长位于632～636 nm,表观摩尔吸光系数相近,ε为 0.89～1.15×105 L?mol-1?cm-1。以634 nm作为测定波长,改变混合稀土的配分进行试验,结果表明,La、Ce、Y的比例对稀土总量测定的影响不显著。加入四元混合掩蔽剂,采用本方法对岩石等实际样品中稀土总量进行测定,相对标准偏差（RSD, n=5）为2.0%～2.4%,回收率为 93%～98%。     

Effects of RE on Microstructures and Mechanical Properties of Hot-Extruded AZ31 Magnesium Alloy

Effects of rare earth (RE) additions on microstructure and mechanical properties of the wrought AZ31 magnesium alloy were investigated. The results show that, by adding 0.3%, 0.6% and 1.0% RE elements, the as-cast microstructure can be refined, and the as-cast alloys‘ elongation and tensile strength can be improved. After extrusion, the alloy with 0.3 % and 0.6% RE additions obtain a finer microstructure and the best mechanical properties, but the alloy with 1.0% RE addition has the coarse A1-RE compound particles in grain boundaries which decreased elongation and tensile properties. Usually, Rare earth (RE) elements were used to improve the creep properties of aluminium-containing magnesium pressure die cast alloys at elevated temperatures. In this paper, it is also found that the high temperature strength of extruded materials can be increased by RE elements additions.     

溴酸钾氧化甲基绿催化光度法测定痕量钯

研究了稀硫酸介质中痕量Ｐｄ（Ⅱ）催化溴酸钾氧化甲基绿的褪色反应及动力学条件，建立了高灵敏度测定痕量Ｐｄ（Ⅱ）的新催化光度法。方法的灵敏度为５６７×１０－１２ｇ／ｍｌ，线性范围为０～０１μｇ／２５ｍｌ。用于测定矿石中的痕量钯，结果较好。