干法氟化制备高纯金属镝的工艺研究

介绍了一种制备无水高纯氟化镝的新方法。在氟化炉内的镍制料盘中直接完成了Dy2O3和无水氟化氢气体的氟化反应，然后将钙热还原DyF3制得的粗镝进行熔盐萃取提纯处理，用此式敢可使工业规模化生产的镝金属中的氧，氟含量均小于0.02%，使金属镝的纯度达99.9%以上。     

高纯金属镝的制备工艺研究与工业实践

对高纯金属镝的制备工艺进行了研究，并用此工艺进行了工业实践。表明：采用氟化氢氟化－制备中间合金－低温蒸馏的工艺流程，是工业生产高纯金属镝较为适宜的方法。     

熔盐电解法制备镨钕镝合金的研究

利用4000 A电解槽,在氟化锂-氟化镨钕-氟化镝熔盐体系中,通过电解氧化镝与氧化镨钕的方法,制备了成分稳定的镨钕镝合金,金属直收率大于96%,电流效率大于75%。讨论了电解质组元、温度、阴极电流密度、加料速度对电解过程的影响。同时与钙热法生产金属镝、自耗阴极制备镝铁合金工艺进行综合性对比分析,结果表明,熔盐电解法在成本、工艺稳定、产品质量等方面具有绝对的优势。     

直接还原法制取稀土金属镝

本文就氟化镝钙热直接还原法制取稀土金属镝的有关工艺条件对还朱过程和金属回收率及质量的影响作了较详细的论述和探讨，指出了稀土金属镝还原的最佳配比和工艺条件。     

水蒸汽蒸馏-EDTA滴定法测定氟化镝中氟

探讨了水蒸汽蒸馏分离-富集氟的条件,建立了EDTA滴定法测定氟化镝中氟量的方法。试样经高氯酸分解后,在140～170 ℃的温度下进行水蒸汽蒸馏,溶液中的氟富集于馏分中,在较低的pH值条件下煮沸馏分使氟离子与过量的氯化镧充分反应,待溶液冷却后,以二甲酚橙为指示剂,六次甲基四胺-盐酸为缓冲溶液,用EDTA标准溶液滴定溶液中剩余镧离子,计算得出氟量。干扰试验证明,样品中的稀土、铁、钙、铝、硅等干扰元素可有效与氟分离,对实验结果无影响。方法用于氟化镝中氟量的测定,结果的相对标准偏差(RSD,n=10)为0.48%。对氟化镝实际样品进行分析,结果同碱熔融-EDTA滴定法一致。     

国内稀土市场行情

20 0 3年 2月产品及规格价格 /( 元 /kg)氧化镧 99%～ 99.9% 14～ 2 2氧化铈 99%～ 99.9% 15～ 2 3氧化镨 96%～ 99% 3 5～ 40氧化钕 99%～ 99.9% 40～ 45氧化钐 99%～ 99.9% 18～ 2 6氧化铕 99.99% 2 3 0 0～ 2 60 0氧化钆 99.9%～ 99.99% 3 0～ 5 0氧化镝 99%～ 99.9% 15 0～ 2 0 0氧化铽 99.9%～ 99.99% 13 0 0～ 160 0氧化钇 99.9%～ 99.99% 70～ 85金属镧 99%～ 99.9% 3 8～ 48金属铈 99%～ 99.9% 42～ 5 0产品及规格价格 /( 元 /kg)金属镨 96%～ 99% 5 5～ 65金属钕 99%～ 99.9% 62～ 72金属钐 99%～ 99.9% 12 0～ 160金属镝 99%～ 99…     

国内稀土市场行情

20 0 2年 3月产品及规格价格 / ( 元 / kg)氧化镧 99%～ 99.9%2 0～ 2 4氧化铈 99%～ 99.9%2 0～ 2 4氧化镨 96 %～ 992～ 38氧化钕 99%～ 99.9%4 3～ 46氧化钐 99%～ 99.9%2 3～ 2 6氧化铕 99.99%2 2 0 0～ 2 30 0氧化钆 99.9%～ 99.990～ 5 0氧化镝 99%～ 99.90～ 2 0 0氧化铽 99.9%～ 99.990 0～ 15 0 0氧化钇 99.9%～ 99.99p～ 80金属镧 99%～ 99.9%4 0～ 5 0金属铈 99%～ 99.9%5 0～ 5 6产品及规格价格 / ( 元 / kg)金属镨 96 %～ 99%6 8～ 75金属钕 99%～ 99.9p～ 75金属钐 99%～ 99.9 0～ 180金属镝 99%～ 99.940…     

国内稀土市场行情

2006年8月产品及规格价格/(元/kg)氧化镧99%~99.9%12.5~14.5氧化铈99%~99.9%12.5~15氧化镨96%~99%95~105氧化钕99%~99.9%115~125氧化钐99%~99.9%20~30氧化铕99.99%1900~2200氧化钆99.9%~99.99%30~50氧化镝99%~99.9%600~700氧化铽99.9%~99.99%3500~4500氧化钇99.9%~99.99%50~70金属镧99%~99.9%30~35金属铈99%~99.9%35~45产品及规格价格/(元/kg)金属镨96%~99%145~160金属钕99%~99.9%165~185金属钐99%~99.9%100~140金属镝99%~99.9%850~950混合稀土金属(冶金级)23~30混合稀土金属(电池级)35~45氯化稀土(REO 45%)7.5~8.5碳酸稀土(REO 45%)6.5~…     

国内稀土市场行情

2006年10月产品及规格价格/(元/kg)氧化镧99%~99.9%12.5~14.5氧化铈99%~99.9%12.5~15氧化镨96%~99%140~160氧化钕99%~99.9%150~160氧化钐99%~99.9%20~30氧化铕99.99%1900~2200氧化钆99.9%~99.99%30~50氧化镝99%~99.9%600~700氧化铽99.9%~99.99%3500~4500氧化钇99.9%~99.99%50~70金属镧99%~99.9%30~35金属铈99%~99.9%35~45产品及规格价格/(元/kg)金属镨96%~99%210~230金属钕99%~99.9%210~220金属钐99%~99.9%100~140金属镝99%~99.9%850~950混合稀土金属(冶金级)23~30混合稀土金属(电池级)35~45氯化稀土(REO 45%)12~13碳酸稀土(REO 45%)11~1…     

国内稀土市场行情

2006年12月产品及规格价格/(元/kg)氧化镧99%~99.9%12.5~14.5氧化铈99%~99.9%10~14氧化镨96%~99%140~160氧化钕99%~99.9%150~160氧化钐99%~99.9%20~30氧化铕99.99%1900~2200氧化钆99.9%~99.99%30~50氧化镝99%~99.9%600~700氧化铽99.9%~99.99%3500~4500氧化钇99.9%~99.99%50~70金属镧99%~99.9%30~35金属铈99%~99.9%32~40产品及规格价格/(元/kg)金属镨96%~99%210~230金属钕99%~99.9%210~220金属钐99%~99.9%100~140金属镝99%~99.9%850~950混合稀土金属(冶金级)22~28混合稀土金属(电池级)30~40氯化稀土(REO 45%)12~13碳酸稀土(REO 45%)11~12…     

用盐酸优溶法从NdFeB废料中回收稀土

介绍了盐酸优溶法的基本流程。采用该方法从钕铁硼废料中萃取分离钕镝,制取的氧化镝中w(Dy_2O_3)≥99%,非稀土杂质含量符合国标要求,稀土总回收率大于92%,生产过程稳定。     

Dysprosium cerate nanostructures:facile synthesis,characterization,optical and photocatalytic properties

A facile approach was developed to prepare Dy_2Ce_2O_7 nanostructures. Dy_2Ce_2O_7 nanostructures were prepared by applying cerium(IV) ammonium nitrate and dysprosium nitrate as Ce and Dy precursors. It was found that the kind of connecting agent, space-filling template and chelating agent were significant factors for the control in shape and size. Transmission electron microscopy(TEM), X-ray diffraction(XRD), diffuse reflectance UV-vis spectroscopy(DR-UV-vis), field emission scanning electron microscopy(FESEM), photoluminescence spectroscopy(PL) and energy dispersive X-ray microanalysis(EDX) techniques were applied to characterize the Dy_2Ce_2O_7 nanostructures and investigate their optical characteristics. To examine the photocatalytic activity of as-produced Dy_2Ce_2O_7 nanostructures, the photocatalytic degradation of erythrosine dye as water pollutant was carried out. The results of the photocatalytic investigations suggest as-obtained nano-sized Dy_2Ce_2O_7 product as a new, proper and efficient candidate for photocatalytic usages under UV illumination.     

Magnetron sputtered Dy_2O_3 with chromium and copper contents for antireflective thin films with enhanced absorption

Dy_2O_3 is a rare earth oxide having a number of advanced applications in various fields including protective or antireflective coatings, Main objective of this novel research work is to check the effect of Cr and Cu addition on different properties of Dy_2O_3 and achievement of antireflective thin films with enhanced abso rption. Thin films of these materials we re deposited using DC magnetron with reactive cosputtering. XRD studies reveals the crystalline nature of thin films having Dy_2O_3(222) reflection in all samples with Cr_2O_3(116) and CuO(111) reflections in Cr and Cu containing compositions. Field emission scanning electron microscopy demonstrates the homogeneous deposition of thin films with uniform shape, size and distribution of grains. Refractive index, extinction coefficient and absorption coefficient significantly increase while optical reflectance decreases with Cr and Cu mediation corroborating an improved antireflective mechanism. The imaginary part of dielectric constant is found to increase slightly with low tangent loss for Cr containing composition co nsidered favorable for energy storage applications.     

Identification of ions present in LiF-DyF3 melts and the mechanism of Dy2O3 dissolution therein

Herein, the present paper were attempted to identify ions in LiF-DyF_3 melts according to the law of decreasing primary crystallization temperature and model analysis. Specifically.the primary crystallization temperatures of LiF-DyF_3 and LiF-DyF_3-Dy_2O_3 melts with various DyF_3 and Dy_2O_3 contents were determined by differential scanning calorimetry(DSC), and reactions occurring in the above melts were investigated using ideal dilute solution(Temkin and Flood) models. Moreover, crystal phases produced by rapid solidification of LiF-DyF_3, LiF-Dy_2O_3, DyF_3-Dy_2O_3, and LiF-DyF_3-Dy_2O_3 melts were identified by X-ray diffraction(XRD) analysis. The primary crystallization temperature of LiF-DyF_3 melts exhibits an approximately linear decrease with increasing molar fraction of DyF_3, and the general formula of complex ions in these melts is expressed as DyF_x~((3-x)),e.g., DyF_4~-. Finally, we investigated the dissolution of Dy_2O_3 in LiF-DyF_3 melts, showing that it was chemical in nature and afforded Dy_(1+x)O_(3x)F_(3-3x) and DyOF.     

NIR emitting terephthalates(Sm_xDy_yGd_(1-x-y))_2(tph)_3(H_2O)_4 for luminescence thermometry in the physiological range

The first luminescence thermometer based on coordination compound of samarium and dysprosium is repo rted.High luminescence intensity and high signal resolution are reached thanks to the concentration quenching reduction due to the use of the trimetallic complexes of Sm-Dy-Gd.The best thermometric properties in a wide temperature range among the studied systems are demonstrated by(Sm_(0.2)Dy_(0.15)Gd_(0.65))_2(tph)3(H_2 O)_4.The sensitivity reaches 0.5%/K in visible range and 1.2%/K in NIR range at low temperatures and 0.5%/K and 0.8%/K in physiological range.     

含钛低碳钢凝固过程中氧化钛形成的热力学

通过研究含钛低碳钢的热力学,确定了在凝固过程中形成氧化钛的最佳钢液条件。计算结果表明：在含钛低碳钢中,为促进凝固初期析出Ti2O3从而细化凝固组织,关键的工艺要点是控制钢液中氧含量在0．0005％～0．0030％,铝含量小于0．001％,氮含量小于0．014％。     

Enhanced photocatalytic activity of Gd~(3+) doped TiO_2 and Gd_2O_3 modified TiO_2 prepared via ball milling method

Gd~(3+)/TiO_2 and Gd_2O_3/TiO_2 nanoparticles were prepared by ball milling method.The effects of Gd~(3+)ion and Gd_2O_3 on the structure and optical property of TiO_2 were studied by XRD and UV-vis DRS.Specific surface area was determined by Brunauer-Emmett-Teller(BET)method.The morphology and elemental composition were characterized by SEM-EDS.XPS was used to determine the surface compositions and chemical character of elements.The sample sizes and microstructures were observed by TEM.The photocatalytic activities of TiO_2 nanoparticles modified with rare earth metal gadolinium(Gd~(3+)ion or Gd_2O_3)were evaluated by degradation of methylene blue(MB)under UV light.Experimental results indicate that 2,5 mol%Gd~(3+)/TiO_2 shows the best photocatalytic activity compared with Gd_2O_3/TiO_2 and pure TiO_2.The existence of gadolinium can exhibit the aggregation and induce lattice distortion of TiO_2 obtained from XRD,SEM and TEM results.The band gap energy of 2.5 mol%Gd~(3+)/TiO_2 decreases to3.07 eV and it leads to visible light absorption response which can be seen from UV-vis absorption spectra.The surface area of 2.5 mol%Gd~(3+)/TiO_2 equals to 85.8 m~2/g and average crystal size is 21.1 nm.EDS and XPS analyses reveal that gadolinium can be introduced either into TiO_2 lattice or adsorbed on the surface of TiO_2.The content of surface OH groups in 2.5 mol%Gd~(3+)/TiO_2 is 50,88%(1.55 times higher than that of pure TiO_2)and the content of lattice oxygen decreases to 11.26%.The MB(25 mg/L)degradation reaction rate constants of 2,5 mol%Gd~(3+)/TiO_2,0.5 mol%Gd_2O_3/TiO_2 and pure TiO_2 were0.0713,0.0588 and 0.0263 min~(-1),respectively.The degradation rates of rhodamine B(30 mg/L)in 60 min are 97,9%,90.1%and 84.6%for 2,5 mol%Gd~(3+)/TiO_2,0.5 mol%Gd_2O_3/TiO_2 and pure TiO_2,respectively.     

钕铁硼废料中钕、镝及钴的回收

研究了钕铁硼废料中钕、镝、钴的回收与分离,根据废料中所含元素的化学性质,选择了硫酸溶解、复盐沉淀稀土、碱转化、盐酸溶解、复盐沉淀铁及萃取分离等手段,成功的将钕铁硼废料中有价值的元素进行了提取,得到了纯度较高的氧化钕、氧化镝及氧化钴。