多面体镧铈铽氧化物荧光粉的制备研究

采用共沉淀-焙烧法制备镧铈铽氧化物绿色荧光粉,研究了表面助剂、酸碱度、底液溶剂及反应温度对镧铈铽氧化物形貌的影响.用X衍射、扫描电镜以及光学显微镜对产物进行分析表征.结果表明,前驱体镧铈铽草酸盐的结晶环境对镧铈铽氧化物的形貌有着重要影响;在非离子表面助剂、强酸性和有机溶剂做底液的体系环境中更利于得到分散性好、形貌规则、球形度较高的多面体镧铈铽氧化物.     

盐酸体系中制备氢氧化铈的工艺研究

研究了用氯化铈溶液为原料制备氢氧化铈,考察了氯化铈溶液浓度、H_2O_2加入量、NH_3·H_2O用量及反应温度对氢氧化铈中铈氧化率的影响,确定最优工艺条件。结果表明:在氯化铈质量浓度120 g/L、H_2O_2用量为CeO_2质量的0. 7倍、NH_3·H_2O用量为理论量130%、反应温度50℃条件下,得到铈氧化率大于97%,w(Cl-)0. 15%的氢氧化铈,且在常温下能溶于HNO_3溶液。     

微波快速固相合成铈掺杂镥铝石榴石

通过微波固相法快速合成了名义组成为Lu_(3-x)Ce_xAl_5O_(12)(x=0.04~0.10)的镥铝石榴石荧光粉,研究了微波辐射时间和铈掺杂量对荧光粉物相组成和发光性能的影响。结果表明,微波加热20~30 min即合成出纯度较高的镥铝石榴石,LuAG:Ce~(3+)的发射峰约为516 nm,激发峰约为342 nm和441 nm,在相同铈原子比条件下延长合成时间有利于提高发光性能。制备的荧光粉颗粒大部分为2~4μm的椭球形,小部分呈针棒状,长5~10μm,直径约1μm;颗粒间有轻微烧结团聚。     

铈在重轨钢中行为特性的热力学模型分析

以重轨钢为研究对象,建立可以定量描述稀土在重轨钢中行为特性的热力学模型,并通过实验验证了模型的精确度.利用该热力学模型,研究分析了在不同氧、硫的质量分数条件下,铈加入量对重轨钢液及其凝固过程中铈的赋存状态以及夹杂物组成的影响作用规律,得到以下结论:当钢中氧、硫的质量分数较低时,随着铈加入量的增加,Ce2O2S的析出量略有减少;当钢中氧、硫的质量分数较高时,随着铈加入量的增加,Ce2O2S的析出量有所增加;铈加入量的增加以及温度的下降均有利于Ces的析出;当钢中氧、硫的质量分数较低时,在凝固过程中钢中析出CeN和固溶铈;随着铈加入量的增加,CeN的析出温度和析出量均有所增加,当CeN的析出达到平衡时,固溶铈大量析出.     

硝酸钠为氧化剂的碳酸稀土焙烧过程研究

对以硝酸钠为氧化剂的富铈混合碳酸稀土焙烧过程进行了实验研究。通过对氧化剂加入量、焙烧温度、焙烧时间的考察 ,得出了铈氧化率的变化规律。研究结果证明 ,硝酸钠对铈的氧化作用是显著的。     

碳酸钠焙烧盐酸浸出分解氟碳铈矿精矿工艺的研究

系统地研究了焙烧温度、焙烧时间和碳酸钠的加入量对氟碳铈矿精矿焙烧分解的影响及浸出时间、浸出温度、盐酸浓度和盐酸用量对三价稀土和铈的浸出率的影响。针对氟碳铈矿精矿的分解,提出了碳酸钠焙烧、水洗除杂、稀盐酸浸出处理氟碳铈矿精矿的简单工艺。在实验室内扩大实验的条件下,首次由焙烧、浸出两步制得了高质量的高铈抛光粉,同时也得到了制取少铈富镧氯化稀土的原料。     

溶胶-凝胶法制备的BaMgAl10O17:Eu2+荧光性能研究

研究了柠檬酸为络合剂的溶胶-凝胶法制备的BaMgAl10O17Eu2+蓝色荧光粉的荧光性能,考察了Eu 2+掺杂量和晶化温度等因素对荧光粉的紫外和真空紫外波段激发的荧光性能的影响,并通过X射线衍射分析,探讨了Eu2+掺杂量引起的晶胞参数和荧光粉发射波长的变化.结果表明BaMgAl10O17Eu2+随着Eu2+掺杂量的增加,除荧光强度发生变化外,发射光谱的波长发生红移;真空紫外波段激发,Eu2+的最佳添加量为0.1,紫外波段激发下为0.12,发射峰波长均为450 nm;晶化时间2小时,温度在1300℃以上更好.     

PYG型稀土飞点扫描荧光粉

本文介绍了稀土飞点扫描荧光粉,提出了铈激活钇铝镓石榴石的制备工艺。研究了镓取代对峰值的影响。证明镓取代可使峰值向短波长方向移动。以镓取代2个铝时,即发绿光的 PYG 飞点扫描荧光粉发射强度最大。试验对粉的粒度、晶体结构进行了测定,并制成高分辨率飞点管测试了亮度和耐灼伤性能。在实际应用中得出管的寿命及有关数据。PYG 荧光粉经用户使用鉴定取得满意结果。     

微波辅助液相法制备CaMoO4∶Eu3+荧光粉

采用微波辅助液相沉淀法制备了Ca1-xMoO4∶ Eu3+(0.05≤x≤0.09)系列红色荧光粉.通过荧光光谱仪、SEM、XRD测试和表征了该荧光粉的荧光性能、形貌、结构.结果表明,当Eu3+掺杂量为0.07,烧结温度为900℃,保温时间为3h时,可获得性能最佳的荧光粉,在395 nm和465 nm波长激发下,在616 nm处出现了很强的发射峰,对应于Eu3+的5D0→7F2的跃迁.采用微波辅助液相沉淀法制备的荧光粉发光强度高于高温固相法所制备的荧光粉,适合白光LED用红色荧光粉.     

纳米Ce/TiO2光催化剂的制备及光催化性能

以TiCl4为原料,Ce(NO3)2·6H2O为掺杂剂,制备了铈掺杂TiO2纳米粒子并进行了X射线衍射表征和气相光催化性能评价。实验结果表明,铈掺杂对样品的光催化活性有影响,随着掺铈量的增加样品的光催化活性提高。掺铈量大于4%以后活性变化不再明显。样品的焙烧温度和时间也对样品的光催化活性有影响。此外,样品的粒径随制备中的pH值降低而减小。     

熔炼次数对M17返回料合金成分、组织和性能的影响

实验结果表明,M17铸造高温合金(%:0.16C、8.79Cr、5.79A1、4.93Ti、3.29Mo、15.20Co、0.78V、0.015B、0.073Zr、0.002S、0.001P、0.001 1O、0.001 0N)经25 kg真空感应炉返回重熔后,Si含量随重熔次数的增加而略有增加,合金中主要元素和其它杂质元素S、P、H的含量变化不大,而氧、氮略有增加;合金中初生碳化物由新合金中的草书体逐渐向返回合金块状转变,初生碳化物的遗传性堵塞合金凝固时的补缩通道,使返回料合金的疏松倾向增大,高温塑性下降较大。     

China's Major Non-ferrous Metals Imports & Exports

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Zinc Production by Province in 2014

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80% of Chinese Firms Purchasing Overseas Mines Ended up in the Red

<正>Minmetals Resources acquired the world’s largest copper mine under construction for USD5.85 billion.One after another,listed companies Jien Nickle,China Molybdenum and Chihong Zinc and Germanium raised money to get involved in overseas mining projects…SOEs and private enterprises are engaged in a frenzy of overseas mine purchasing.A reporter with Economic     

Copper Processing Profit Dropped Sharply,Copper Consumption Will Face Impact in the Second Half of the Year

正Judging from China’s copper consumption field,the biggest consumption unit is electric power,which accounts for 47%of total consumption;it is followed by light industry sector,including household electrical appliance,machinery,durable goods and hardware etc,which accounts for 22%of total consumption;followed by transportation field,     

Central Geological Prospecting Fund Newly Added 16.47 Million Tonnes of Bauxite in 2013

正In 2013,the Central Geological Prospecting Fund(CGPF)Project newly discovered 15 ore fields,including 3 large above ore fields,and 5medium sized ore fields.The reporter learned from the recently published"Annual Report of Central Geological Prospecting Fund Project(2013)"that,from 2006 to 2013 the CGPF     

Manufacturers of Copper Tube for Central Air Conditioner Use Face Mounting Pressure in the Final Quarter of the Year

正This year,the investment growth rate of real estate industry continued to slow down,sold area of commercial housing also dropped significantly,which brought huge pressure to the domestic air conditioning manufactures.In the first half of the year,by relying on high growth in national financial expenditure,along with investment in public infrastructure     

Xinjiang Ranks No.1 in Production of Primary Aluminum in China

正Kang Yi,Honorary Chairman of China Nonferrous Metals Industry Association,said recently at the Forum on Development of the Non-ferrous Metals Industry in Central and Western China held in Zhengzhou that,as more and more electrolytic aluminum factories in Xinjiang came into operation,the electrolytic aluminum output of Xinjiang had reached2,275,000 tons in the first 7 months this year,     

Shenhuo Coal Industry and Electricity Power Completed800,000 t/a Aluminum Project in Xinjiang

正"Xinjiang project has been completed according to schedule,but total completion and total start of production are two different concepts,after completion it still needs a gradual process of reaching production target."On the morning of November 3,Shenhuo Coal Industry and Electricity Power told investors the above statement on the investor interaction platform.     

Guangdong Metal Transaction Center has Become the Second Largest Precious Metal Transaction Platform Nationwide

正The reporter learned from Guangdong Province Precious Metal Transaction Center that in 2013the Center maintained healthy development momentum,and had become the second largest precious metal transaction platform in China in terms of market size;currently Guangdong is quickening steps of financial innovation for the Center,aiming to build a transaction center with international core competitiveness.