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。     

Study of the Coarse Blocky Compounds in the As－cast 7075 Aluminium Alloys Containing Rare Earth Elements

ＳｔｕｄｙｏｆｔｈｅＣｏａｒｓｅＢｌｏｃｋｙＣｏｍｐｏｕｎｄｓｉｎｔｈｅＡｓ－ｃａｓｔ７０７５ＡｌｕｍｉｎｉｕｍＡｌｌｏｙｓＣｏｎｔａｉｎｉｎｇＲａｒｅＥａｒｔｈＥｌｅｍｅｎｔｓＰａｎＦｕｓｈｅｎｇ；ＺｈｏｕＳｈｏｕｚｅ；ＤｉｎｇＰｅｉｄａｏ；（Ｃｈ...     

Effect of Rare Earth Elements on the Impact Wear Resistance of Nitrocarburizing Layers

In this paper the effect of rare earth elements on the toughness and impact wear resistance of nitrocarburiz-ing layers is studied.The experimental results show that the toughness and impact wear resistance ofRE-nitrocarburizing layers are increased significantly compared with that of conventional nitrocarburizing lay-ers.The service life of hot die for manufacturing bicycle bolts increased more than 100%.The impact wearmechanism of RE-nitrocarburizing layers is investigated by SEM as well.     

Study on the Interaction between Rare Earth and Carbon in High Carbon Steel

ＳｔｕｄｙｏｎｔｈｅＩｎｔｅｒａｃｔｉｏｎｂｅｔｗｅｅｎＲａｒｅＥａｒｔｈａｎｄＣａｒｂｏｎｉｎＨｉｇｈＣａｒｂｏｎＳｔｅｅｌ￥ＬｉｎＱｉｎ（林勤），ＦｕＴｉｎｇｌｉｎｇ（付廷灵），ＹｕＺｏｎｇｓｅｎ（余宗森），ＹｅＷｅｎ（叶文）（Ｕｎｉｖｅｒｓｉｔ...     

Quantum Chemical Calculation on the Structures and Electronic Properties of Phosphonate Ester as Rare Earth Extractants

ＱｕａｎｔｕｍＣｈｅｍｉｃａｌＣａｌｃｕｌａｔｉｏｎｏｎｔｈｅＳｔｒｕｃｔｕｒｅｓａｎｄＥｌｅｃｔｒｏｎｉｃＰｒｏｐｅｒｔｉｅｓｏｆＰｈｏｓｐｈｏｎａｔｅＥｓｔｅｒａｓＲａｒｅＥａｒｔｈＥｘｔｒａｃｔａｎｔｓＺｈａｎｇＳｈａｏｗｅｎ（张绍文），Ｓｈ...     

Effects of La-Rich Rare Earth Alloys on Structure and Mechanical Properties of ZL101A Alloy

ＥｆｅｃｔｓｏｆＬａＲｉｃｈＲａｒｅＥａｒｔｈＡｌｏｙｓｏｎＳｔｒｕｃｔｕｒｅａｎｄＭｅｃｈａｎｉｃａｌＰｒｏｐｅｒｔｉｅｓｏｆＺＬ１０１ＡＡｌｏｙＬｉＨｕａｊｉ（李华基），ＴａｎＨｕｉｘｉｎ（谭会辛），ＺｈｕＺｈｅｎｃｈａｏ（祝阵超）（Ｃｈｏｎｇ...     

高铁稀土精矿硫酸焙烧—浸出试验

某稀土矿经选矿获得的稀土精矿,其稀土含量较低、铁含量高,分别进行了浓硫酸低温焙烧及浓硫酸高温焙烧试验。结果表明,以浓硫酸低温焙烧工艺处理该高铁稀土精矿,在较佳条件下,稀土浸出率达96.94%,钍浸出率达97.36%,铁浸出率亦达92.71%;以浓硫酸高温焙烧工艺处理该高铁稀土精矿,在较佳条件下,稀土浸出率可达90.15%,钍浸出率为42.10%,铁浸出率仅12.44%。浓硫酸低温焙烧工艺获得的稀土浸出液铁含量高、酸度大(Fe含量23g/L左右,pH0.5),从高铁、高酸稀土溶液中回收稀土产品,其工艺过程较繁琐。浓硫酸高温焙烧工艺处理该高铁稀土精矿,可获得铁含量较低(Fe含量约2.3g/L)的稀土浸出液,从低铁含量的稀土溶液中回收稀土产品,其工艺流程较简短,废水较易治理,在生产成本上也具有优势。     

稀土元素的特殊性质及其应用

本文从稀土元素微观结构角度，揭示了稀土元素的某些特殊性质，并指出这种特性与应用机理有必然的联系。从而启迪稀土使用者，掌握和了解稀土的基本特性，才能自由地驾驭稀土的应用。     

变价稀土元素对镁合金熔体中镁元素活度的影响

根据Miedema二元合金生成焓模型,结合相关热力学数据,对Mg-Eu,Mg-Yb的四个变价二元合金体系中镁元素的活度进行计算。结果表明,对这四个合金体系,低价稀土金属元素将使镁的活度变化曲线对理想溶液曲线产生正偏差,而低价稀土元素体系将出现负偏差。控制不同价态稀土元素的添加量将可在一定范围内控制合金熔体中镁的活度。     

Study on Adsorption of Rare Earth Elements by Kaolinite

Rareearthelements (REEs)werewidelyappliedtotracingthesourcesofmaterialsandtostudyingtheirevolutionprocessesinmanyfieldsofearthscienceinconsiderationoftheirsimilarityandsystematicdiffer enceinchemicalproperties .Furthermore ,lanthanidesarebothimportantprod…     

盐酸浸出中低品位胶磷矿中稀土的研究

采用盐酸对贵州织金磷矿进行酸解,研究了盐酸浓度、反应时间、酸料比和温度等对磷矿中稀土浸出率的影响。结果表明,在下述最佳工艺条件下稀土浸出率可达98%以上:浓盐酸(11mol/L)、反应时间120min、酸料比2∶1、温度50℃。     

Study on Mechanism of Rare Earth PVC Stabilizer

Rare earth compounds can be used as PVC thermal stabilizers. According to the infrared spectra of the mixture of PVC and some stearates, the mechanism of stabilization of different stearates was studied. The specialty of rare earth stabilizers was found. They can change the conformation of PVC and restrain the elimination of HCI. From this aspect, the unique synergetic effect with other stabilizers of rare earth compounds can be explained.     

Effects of Heavy Rare Earth Elements on Properties ofAmorphous NiB Alloy Catalyst

Gas-phase hydrogenation of benzene was selected as probe reaction to study the effects of heavy rare earth ele-ments on the catalytic activity and sulfur resistance of amorphous NiB alloy. XRD, DSC, CO chemical adsorption, TPR and TPD were used to characterize the bulk and the surface properties of the alloys, respectively. The results indicate that the addition of a small amount of heavy rare earth (HRE) elements obviously improves the activity, thermal stability and sulfur resistance of amorphous NiB alloy. The HRE can alter H2 adsorption bond strength, increase the surface area of ac-tive nickel and the number of active centers over the surface of NiB alloy and it also can decrease the activation energy of NiB alloy for benzene hydrogenation. There are four kinds of adsorbing sites over the surface of NiB and NiBRE, only three kinds of them have concerned with the reaction.     

稀土化合物对粉末冶金镍基合金摩擦磨损性能的影响

用粉末冶金热压方法制备了几种含不同稀土化合物（LaF3,CeO2,La2O3)的Ni基合金，将合金制备为块样，45^#钢为环样，在环－块摩擦试验机上考察了稀土化合物含量及其种类对Ni基合金摩擦磨损性能的影响，研究结果表明：添加稀土化合物可明显改善合金在高载高速下的耐磨性能，这与其摩擦表面形成摩擦保护性“釉质层”密切相关。     

稀土元素对活性污泥影响的初步研究

初步研究了稀土元素镧（Ｌａ）、铈（Ｃｅ）、镨（Ｐｒ）、钕（Ｎｄ）及其混合物对活性污泥生长的影响。结果表明，５０ｍｇ／Ｌ浓度以上的稀土元素对活性污泥生长有明显的影响，表观变色上浮；显微可见菌胶团疏松分散，原生动物个体游离。     

喷施稀土对茶叶中不同状态的稀土元素组成及含量的影响

茶树叶面喷施稀土是一项增产提质的栽培措施。但人们关心外源稀土对茶叶中稀土元素(REE)含量、组成及存在状态所产生的影响。试验表明,喷施至采摘间隔期愈长,喷施稀土对茶叶中稀土含量及组成等的影响愈小。茶叶中REE约有80%左右以水不溶态残存于茶渣中,不进入茶汤。进入茶汤中的REE约有10%是以稀土多糖状态存在,其中尤以La、Ce、Nd为主。间隔期愈短,稀土进入茶汤的量及参与稀土多糖配合物的量愈高。     

某低品位复杂稀土精矿中提取稀土的研究

对某低品位复杂稀土精矿采用传统的浓硫酸低温焙烧工艺,可以较好的浸出稀土和铍,浸出率分别达到95%和90%以上,但钽、铌浸出率只能达到40%左右;采用添加活化剂后,可使钽铌的浸出率提高到80%,同时稀土和铍的浸出率也分别达到97%和99%;将水浸液采用添加草酸沉淀稀土,经过煅烧后成稀土氧化物后稀土总量达到86%,将稀土氧化物采用盐酸溶解后,通过调整pH值,除去部分杂质,采用碳铵沉淀稀土,得到碳酸稀土,非稀土杂质小于2%.     

夹杂物对稀土金属丝塑性和韧性的影响

稀土金属中的酸不溶物是影响其塑性、韧性的重要原因,将所述酸不溶物含量限于一定水平,则能保证稀土金属合格的塑性和韧性.     

稀土对60CrVA钢组织和性能的影响

用兴澄特钢生产的φ18 mm 60CrVA圆钢做原料,在25 kg真空感应炉中,进行了三炉添加稀土的试验.对钢的化学成分、气体含量、金相以及硬度、横向韧性、塑性等性能进行检验.稀土改变了钢中夹杂物形态和细化了珠光体片间距,提高了钢的韧性和冲击性能,有利于延长产品的使用寿命.     

Synthesis of Mono-esters of Phenyl-and Substituted Phenylphosphonic Acids and Their Performance in Rare Earth Extraction

Methodsfor the synthesis of acidic phenyl-and substituted phenylphosphonates bearing a branched longchain ester alkyl group are described.These synthetic routes are incomparably superior to other methods in vari-ous aspects including better reaction yield and higher purity of the product.The behaviour of themono(2-butyloctyl)esters and mono(2-methyldodecyl)esters of both phenyl-and o-methylphenylphosphonicacids thus obtained in extraction of lanthanum,praseodymium,neodymium and lutecium as representatives oflight and heavy rare earths,is investigated and discussed on the basis of their chemical structure.The dependenceof the extraction constants and separation factors accords with the Reactivity-Selectivity Principle in solvent ex-traction proposed by us.The composition and structure of the extracted species have been characterized byinfra-red and proton nuclear magnetic resonance spectroscopy in addition to elemental analyses.