固氟氯化铵焙烧法从包头稀土矿中回收稀土的动力学

研究了固氟氯化铵焙烧法分解包头混合型稀土精矿回收稀土的动力学.结果表明:固氟焙砂的氯化反应过程符合Bagdasarym提出的区域反应速率模型,氯化反应过程经过了两个串联反应步骤,且反应生成物的核按一个方向长大;反应速率方程遵从Erofeev方程的串联反应步骤模型,反应表观活化能Ea为36.831 KJ·mol-1,过程控制步骤是内扩散控制.     

镁合金表面稀土转化处理技术的研究进展

镁合金稀土转化膜技术是近年发展起来的一种环保型镁合金表面处理新技术.综述了国内外镁合金稀土转化膜研究的现状及进展,分析了镁合金稀土转化膜处理工艺的成膜影响因素、膜的形成机制等.     

镁合金表面稀土转化膜研究进展

镁合金作为结构材料具有十分突出的性能,但镁的低电位导致其耐蚀性很差,大大限制了镁合金的广泛应用.化学转化膜作为一种简单、有效的防腐蚀表面处理方法得到了迅速发展.相较目前成熟但污染严重的铬酸盐转化膜处理工艺,稀土盐转化处理因其良好的环境友好性和耐蚀性能而备受关注.总结了稀土盐转化膜的成膜工艺及膜的性能、膜的组成及微观形貌、膜的形成机理以及膜的耐腐蚀机理等方面的研究现状,提出了转化膜的一些技术问题,并展望了该技术的发展趋势.     

稀土对铝导线导电性的影响

研究了稀土含量对高纯铝和工业纯铝导线导电性的影响。稀土使高纯铝的电阻率增加。在所研究的稀土含量0.034-1.04%Ce 及0.21-0.51%RE 范围内,没有发现稀土降低电阻率的现象。结合铝导线中铁和硅的影响,对稀土的作用及其与杂质铁、硅的综合作用进行了讨论。     

用分光光度法测定稀土硬质合金中的铈

基于在稀硫酸介质中铈（Ⅳ）能氧化甲基红使之褪色的原理，建立了用分光光度法测定稀土硬质合金中的铈的操作步骤，并分析了Ｈ２ＳＯ４酸度、共存离子、甲基红用量等对测定的影响。结果表明：本法操作简便，试剂简单，可测定０．０１％～１％的铈。     

焙烧氟碳铈矿硫酸浸出稀土的动力学(英文)

研究了硫酸浸出德昌稀土与天青石共伴生矿的焙烧矿过程。考查粒度、搅拌速度、硫酸浓度和温度对稀土浸出率的影响,并对稀土的浸出动力学进行分析。在选定的浸出条件下:粒径0.074～0.100mm、硫酸浓度1.5mol/L、液固比8:1、搅拌速度500r/min,稀土浸出反应受内扩散控制,表观活化能为9.977kJ/mol。     

稀土Ce对铸态AlCuMgAg合金耐热性能的影响

采用拉伸测试与透射电镜(TEM)，研究了稀土Ce对铸态Al-5.3Cu-0．8Mg-0．6Ag(质量分数)合金的组织和耐热性能影响。结果表明，添加质量分数为0．20％～0．45％的Ce，在室温到300℃，铸态合金的室温抗拉强度和高温耐热性能得到了提高。金相显示，稀土Ce的添加能明显细化铸态合金的晶粒，减少晶界上Cu的偏析。透射电镜分析表明，合金中的主要强化相为Ω相；添加微量Ce能细化合金中的强化相，提高该相的析出密度。同时研究也表明，当合金中同时添加微量Ce和Ti时，铸态合金中形成了一种AlxTi6Ce3Cu的大块稀土化合物相，这种化合物相严重降低了合金的拉伸性能。     

Recovery of RE from Baotou rare earth concentrate with chlorination roasting

1　INTRODUCTIONBaotourareearthdepositisthelargestoneintheworld .Theconcentrateisthemixtureofbastnaesite(REFCO3)andmonazite (REPO4 )andtheratioofbastnaesitetomonaziteisgenerally 7∶3.ThemainprocessestorecoverREfromtheconcentrateincludetheroastingwithsulfuricacid ,alkaliheatingprocessandhightemperaturechlorinationetc[1] .Thecon ventionalprocessesproducewasteacid ,alkaliordis chargegastopollutetheenvironment ,thereforethemetallurgiststrytoseekthegreenchemistryprocesswithlowcost,simplepro…     

Column leaching process of rare earth and aluminum from weathered crust elution-deposited rare earth ore with ammonium salts

In order to better understand the leaching process of rare earth (RE) and aluminum (Al) from the weathered crust elution-deposited RE ore, the mass transfer of RE and Al in column leaching was investigated using the chromatographic plate theory. The results show that a higher initial ammonium concentration in a certain range can enhance the mass transfer process. pH of leaching agent in the range of 2 to 8 almost has no effect on the mass transfer efficiency of RE, but plays a positive role in the mass transfer efficiency of Al under strong acidic condition (pH<4). There is an optimum flow rate that makes the highest mass transfer efficiency. The optimum leaching condition of RE is the leaching agent pH of 4–8, ammonium concentration of 0.4 mol/L and flow rate of 0.5 mL/min. The mass transfer efficiencies of RE and Al both follow the order: (NH₄)₂SO₄<NH₄Cl<NH₄NO₃, implying the complexing ability of anion.     

RECOVERING RE FROM LEACHING LIQUOR OF RARE EARTH ORE BY EXTRACTION

ＲＥＣＯＶＥＲＩＮＧＲＥＦＲＯＭＬＥＡＣＨＩＮＧＬＩＱＵＯＲＯＦＲＡＲＥＥＡＲＴＨＯＲＥＢＹＥＸＴＲＡＣＴＩＯＮＣｈｉＲｕ＇ａｎ；ＸｕＪｉｎｇｍｉｎｇ；ＨｅＰｅｉｊｉｏｎｇ；ＺｈｕＹｏｎｇｊｕｎ（ＩｎｓｔｉｔｕｔｅｏｆＮｕｃｌｅａｒＥｎｅｒｇｙＴｅｃ...     

Leaching hydrodynamics of weathered elution-deposited rare earth ore

1　ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｗｅａｔｈｅｒｉｎｇｃｒｕｓｔｅｌｕｔｉｏｎ ｄｅｐｏｓｉｔｅｄｒａｒｅｅａｒｔｈｏｒｅｉｓａｋｉｎｄｏｆｒｉｃｈｒａｒｅｅａｒｔｈｒｅｓｏｕｒｃｅ[1] .Ｔｈｅｒａｒｅｅａｒｔｈｉｎｔｈｅｗｅａｔｈｅｒｉｎｇｃｒｕｓｔｅｌｕｔｉｏｎ ｄｅｐｏｓｉｔｅｄｒａｒｅｅａｒｔｈｏｒｅｍａｉｎｌｙｅｘｉｓｔｓｗｉｔｈｔｈｅｉｏｎ ｐｈａｓｅａｄ ｓｏｒｂｅｄｏｎｃｌａｙｍｉｎｅｒａｌｓ[2 ] ,ａｎｄｃａｎｂｅｌｅａｃｈｅｄｂｙｉｏｎ ｅｘｃｈａｎｇｅｍｅｔｈｏｄ[3] .Ｍａｎｙｉｎｄ…     

Leaching process of rare earths from weathered crust elution-deposited rare earth ore

In order to strengthen the leaching procedure, the chemical processes of leaching rare earths (RE) from the weathered crust elution-deposited rare earth ore were investigated frow the viewpoints of kinetics, hydrodynamic and mass transfer. The results show that the leaching hydrodynamics follows the Darcy law. The leaching kinetics can be described by the shrinking core model; the leaching process is controlled by diffusion of porous solid layer; and the mass transfer can be described with Van Deemter equation. This provides a theoretic basis and a scientific approach with high efficiency and optimized extraction conditions in industrial practice.     

Recovering indium with sulfating roasting from copper-smelting ash

A technology for recovering indium from Jinchuan copper-smelting ash was developed. Indium in the ash was first enriched to the leaching-slag in leaching process,and then recovered by sulfating roasting. The method included mixing the leaching-slag with sulfuric acid,making them into particles,roasting the mixture,and then leaching the calcine with hot water. Above 90% of indium in calcine could be dissolved into the leaching solution. The optimized conditions were determined as follows： the mass ratio of sulfuric acid to leaching slag was 0.1,the roasting time was about 1 to 1.5 h in the temperature range of 200-250℃,and the calcine was leached for 1 h with 5：1 of liquid/solid ratio at 60℃. Over 99% of indium in leaching solution was finally enriched by Zn substitution or sulfide precipitation.     

Laser surface coating of RE bioceramic layer on TC4

1　ＩＮＴＲＯＤＵＣＴＩＯＮＦｏｒａｌｏｎｇｔｉｍｅ ,ｓｔａｉｎｌｅｓｓｓｔｅｅｌｓ ,Ｃｏ ｂａｓｅｄａｌ ｌｏｙｓ ,ｔｉｔａｎｉｕｍａｎｄＴｉ ｂａｓｅｄａｌｌｏｙｓｈａｖｅｂｅｅｎｕｓｅｄａｓｒｅｐａｉｒｉｎｇａｎｄｉｍｐｌａｎｔｉｎｇｍａｔｅｒｉａｌｓｆｏｒｈａｒｄｈｕｍａｎｔｉｓｓｕｅｓｂｅｃａｕｓｅｏｆｔｈｅｉｒｅｘｃｅｌｌｅｎｔｍｅｃｈａｎｉｃａｌａｎｄｍａ ｃｈｉｎｉｎｇｐｒｏｐｅｒｔｉｅｓ .Ｈｏｗｅｖｅｒ ,ｍｅｔａｌｍａｔｅｒｉａｌｓｈａｖｅｎｏｃｏｎｓａｎｇｕｉｎｉｔｙｗｉｔｈｈｕ…     

Dissolution kinetics of low grade complex copper ore in ammonia-ammonium chloride solution

The leaching kinetics of Tang-dan refractory low grade complex copper ore was investigated in ammonia-ammonium chloride solution. The concentration of ammonia and ammonium chloride, the ore particle size, the solid-to-liquid ratio and the temperature were chosen as parameters in the experiments. The results show that temperature, concentration of ammonia and ammonium chloride have favorable influence on the leaching rate of copper oxide ores. But, leaching rate decreases with increasing particle size and solid-to-liquid ratio. The leaching process is controlled by the diffusion of the lixiviant and the activation energy is determined to be 23.279 kJ/mol. An equation was also proposed to describe the leaching kinetics.     

稀土在渗硼中渗入机制和作用机理的讨论

研究了45钢表面硼稀土共渗，讨论了稀土元素的渗入机制、催渗机理及稀土催渗效果出现最佳值的原因。在硼砂型渗硼剂中加入适量的稀土有利于45钢渗硼层质量、厚度及性能的提高，稀土加入量的最佳值为10％。