黄铵铁矾的制备及其形貌对锂离子电池磷酸铁锂正极材料性能的影响

为探索出红土镍矿杂质Fe高附加值利用的研究，以红土镍矿的硫酸铵焙烧熟料溶出液作为研究对象，以NH4HCO3作为造矾剂制备黄铵铁矾，矾水解后获得锂离子电池正极材料LiFePO4的原料Fe2O3，Fe2O3中加入Li2CO3、磷酸二氢铵NH4H2PO4及蔗糖煅烧制备出锂离子电池正极材料LiFePO4/C。获得最佳造矾条件为:反应时间4 h、反应温度95℃、终点pH值2.5、搅拌速度400 r/min，除铁率在98.35%以上，并采用XRD、SEM和化学分析手段对黄铵铁矾进行了表征；煅烧温度750℃、煅烧时间10 h制备的片状磷酸铁锂在0.1C倍率下的首次放电比容量164.12 mAh/g，0.1C、0.5C、1C、2C、5C倍率下循环10周的容量保持率较颗粒状磷酸铁锂高，表明片状磷酸铁锂有较好的电化学性能。由红土镍矿中的铁元素合成了高附加值锂离子电池LiFePO4正极材料，为红土镍矿资源高效、综合利用提供新技术及理论支持。     

红土镍矿选择性溶出制备黄铵铁矾花球状晶体

以红土镍矿硫酸焙烧熟料溶出液为原料,(NH_4)_2CO_3为碱式调节剂,采用湿法制备黄铵铁矾。研究和分析了反应温度、反应时间和pH值对溶出液中黄铵铁矾生成率的影响,并利用X射线衍射(XRD)、扫描电子电微镜(SEM)和化学成分分析等手段对制备产物进行了表征。研究发现,在反应温度95℃、反应时间4 h、终点pH值是2.5的条件下,黄铵铁矾生成率大于98%,实现了铁的有效分离,得到花球状黄铵铁矾粉体。     

红土镍矿黄铵铁矾法除铁及杂质铁的高值化利用

以红土镍矿为原料,采用硫酸铵焙烧—水浸—黄铵铁矾法除铁,然后再以黄铵铁矾水解所得Fe2O3为原料,加入一定比例的Li2CO3、NH4H2PO4和蔗糖进行还原焙烧制备锂离子电池正极材料LiFePO4/C。采用X射线衍射(XRD)、扫描电子显微镜(SEM)和化学分析等手段对实验样品进行了分析和表征。研究了工艺参数对除铁率和黄铵铁钒形貌以及黄铵铁钒形貌对磷酸铁锂电化学性能的影响。结果表明,最佳造矾条件为:反应时间4h、反应温度95℃、终点pH值2.5、搅拌速度400r/min,在此条件下浸出液除铁率超过98.35%;煅烧温度750℃、煅烧时间10h时制备的片状磷酸铁锂具有较好的电化学性能,在0.1C倍率下的首次放电比容量为164.12mA·h/g,0.1C、0.5C、1C、2C、5C倍率下循环10周的容量保持率较高。研究结果可为红土镍矿资源的高效、综合利用提供新技术及理论支持。     

热酸浸出—铁矾法处理高铟高铁锌精矿的研究

本研究提供了一个有效回收锌、铟的联合湿法流程,对流程中浸出、澄清、黄钠铁钒除铁、铁矾的热学性质、铁矾的焙烧及浸出、钢铁的革取工艺及设备、渣处理等进行了详细的研究。     

红土镍矿-硫酸铵焙烧熟料铁溶出动力学

以红土镍矿-硫酸铵混合焙烧后所得熟料为研究对象,采用水溶出的方法提取铁,系统地研究溶出温度、液固比、溶出时间、搅拌强度对铁溶出率的影响,并对铁的溶出动力学进行探讨。结果表明:在溶出温度60 ℃、溶出时间60 min、液固比2.5 GA6FA 1、搅拌强度400 r·min-1的条件下溶出时,铁的溶出率可达到99%以上;动力学分析表明,铁的溶出反应受外扩散控制,根据阿伦尼乌斯经验方程计算得到反应的表观活化能为E=7.23 kJ·mol-1,得到溶出过程动力学方程为1-（1-α）2/3=0.208 5 exp（-7 234/RT）t。      

Ramu红土镍矿湿法冶炼过程中钪的富集回收

分析了Ramu红土镍矿中金属钪的矿物赋存特性。跟踪考察了钪在Ramu红土镍矿湿法冶炼过程中的走向和分布。在此基础之上,结合工业生产实际,研究了中和除铁铝过程pH值、石灰石乳浆加入速度和搅拌强度对钪富集的影响,给出了合理化建议。结果表明,在Ramu红土镍矿湿法冶炼过程中,大于60%的钪可在中和除铁铝过程的铁铝渣中进行富集。在一段中和除铁铝pH值为3.9,二段中和除铁铝pH值为4.9,匀速加入石灰乳浆且搅拌强度均匀时,钪的富集情况最佳,可得到钪含量为1 300g/t粗钪中间体,且此条件下的浸出液铁铝去除率高,镍钴损失小。     

基于BP神经网络技术的红土镍矿还原焙烧-磁选工艺条件的优化

还原焙烧—磁选工艺可有效提取红土镍矿中的镍和铁等有价金属，由于影响红土镍矿还原焙烧—磁选效果的因素较多，导致工业生产中的选矿指标不稳定。为进一步提高还原焙烧—磁选工艺处理红土镍矿的效果，本研究以青海某镍矿为原料，采用正交试验与BP神经网络相结合的方法，对还原焙烧—磁选工艺的还原剂用量、焙烧温度、料层厚度、焙烧时间及磁场强度等因素进行了优化。结果表明:通过BP神经网络模型优化后的试验条件为还原剂用量9.5%、焙烧温度1 070℃、料层厚度10.0 mm、焙烧时间65 min及磁场强度2.5 kA·m-1，在此条件下可获得产率为30.29%的镍粗精矿，比采用正交试验最优因素组合条件所得的镍粗精矿产率提高了2.83%。      

熔剂性红土镍矿球团的还原焙烧-弱磁选效果

回转窑直接还原红土镍矿存在所需温度高、对耐火材料要求苛刻、还原指标差等问题。为开发一种高效低成本的红土镍矿球团还原工艺,考察了以CaO为熔剂改变红土镍矿碱度对红土镍矿球团还原焙烧-弱磁选效果的影响。结果表明：自然碱度下,在还原温度为1 400 ℃、还原时间为60 min时,所得还原产品经磨矿-弱磁选,获得的磁性产品镍、铁品位分别仅3.8%和72.9%,回收率分别为17.8%和39.8%,磁性产品中含有较多的镁橄榄石和顽火辉石;随着红土镍矿碱度的增加,红土镍矿的软熔温度先降低后提高,碱度为1.0时,红土镍矿的软熔温度最低,比自然碱度时降低了100 ℃;碱度为1.0的红土镍矿球团在1 300 ℃下还原焙烧60 min后,经磨矿-弱磁选,获得的磁性产品镍、铁品位分别为8.7%和83.8%,回收率分别为85.6%和62.8%。XRD和扫描电镜分析结果表明：自然碱度的红土镍矿还原焙烧生成的Fe-Ni合金晶粒多在5 μm以下,并且分布比较分散,还原产品中夹杂有较多的杂质;添加CaO至碱度为1.0时,Fe-Ni合金晶粒可以长大到10~50 μm,还原产品中杂质较少,镍和铁得到了明显的富集。试验结果可以为红土镍矿球团还原焙烧-磁选制取镍铁新工艺提供理论基础。     

赣南某红土镍矿常压酸浸液中杂质离子的除去

赣南某红土镍矿常压酸浸液中含有铁、镁、铜、铅、锌等杂质离子,且这些杂质离子与镍离子分离较困难。采用黄钠铁矾法去除铁离子,达到了99%的去除率;采用硫化钠沉淀法去除铜、铅、锌等重金属离子,达到了90%的去除率;采用氟化钠法去除镁离子,达到了90%的去除率;各作业段镍离子作业损失率分别为15%、12%、5%。     

印尼某红土镍矿常压浸出实验研究

以印尼某地红土镍矿为原料,考察了浸出时间、浸出温度、硫酸浓度、液固比等因素对硫酸常压浸出镍、铁的影响。结果表明,硫酸浸出红土镍矿的适宜工艺参数为: 初始硫酸浓度300 g/L、液固比6∶1、搅拌速度300 r/min、浸出温度85 ℃、浸出时间240 min,此优化条件下红土镍矿中Ni浸出率97%,Fe浸出率83%。对浸出渣进行XRD、SEM分析表明,红土镍矿晶型较稳定,浸出后形貌无较大变化; 浸出渣主要成分为铁氧化物、硅氧化物和铁酸镍、铁酸镁。     

China rare earth market review

正November 21~30,2014Due to weak demand from downstream industries,transactions of rare earth in Chinese domestic market were inactive.It was difficult to sell any rare earth products except for dysprosium oxide and terbium oxide.Suppliers lost confidence in recent market.Demand for rare earth products was soft.Consumers continued to take a wait-and-see attitude.Rare earth export market remained slow.     

Current situation and future trend of China rare earth luminescent materialindustry(continued)

<正>Developing ecological lighting source The world is facing the big problem of energy shortage today and the contradiction between economy development and environmental protection is worsened.Therefore,people are more likely to choose an ecological light source that is more energy efficient and environmental friendly.The choice provides great opportunity for the development of rare earth optical material industry in China.The concept of green lighting positions rare earth luminescent material as a leading player in illumination market.The light source of both rare earth luminescent lamp and LED lamp is ecological and energy saving.This is why     

Galaxy Magnets achieved the net profit of 34.02 million yuan in the first six months of 2014

正Galaxy Magnet announced its financial results for the first half of 2014 on August 14.For the first six months ended on 30 June 2014,Galaxy Magnet achieved operation income of RMB 182.3 million,up8.40% over the same period of 2013,and the net profit attributable to the shareholders of the listed company of 34.02 million yuan,increasing 35.49% over the same period of last year.Stable performance increase was led by development of new customers and application market of magnets.     

Rare Earth Application in Steel in China

<正>China has rich rare earth resources.Output of rare earth and steel in China ranks the top first in the world.However,there is still certain distance between the steel produced in China and developed countries from the point of varieties and quality.China still has to import some types of steel.Improving the quality should be emphasiZed in future development of steel industry in China.Rare earth can be used to upgrade traditional steel     

稀散金属产业的观察与思考

分析了近年来国内外稀散金属产业的生产、应用、资源与市场状况.铟锡氧化物靶材、砷化镓晶片、锗红外材料、铼高温合金和硒在电解锰及玻璃的应用等已成为稀散金属的主要应用领域.稀散金属的产量快速增长达到历史高位而导致了市场的失衡.以GaInP_2/GaAs/Ge,CIGS和CdTe为代表的非硅系太阳能电池是稀散金属的新兴应用领域,将给稀散金属带来日益增长的需求.     

China rare earth market review

正November 1~10,2014Chinese rare earth market was still inactive.Demand for rare earth products was weak.Consumers took a wait-and-see attitude for lower price.As it was an off season for rare earth products,it was expected that prices of rare earth could continue turbulence at the bottom in short terms.Due to a sharp drop,demand for rare earth from downstream recovered.Affected by new energy vehicles,wind powder and energy-efficient appliances,production of rare earth permanent     

China rare earth market review

正August 1~10,2014 There was some good news in rare earth industry recently.Restructuring plans of rare earth groups led by Baotou IronSteel Group and Xiamen Tungsten Group respectively have been approved by MIIT.And rare earth storage policy,which had been expected for a very long time,has been launched officially.Pushed by the good news,rare earth price started to rebound since August 5.Price of didymium oxide and dysprosium oxide rose about 1% to 2%,averagely.About 10% of     

China rare earth market review

正July 1~10,2014Due to weak demand from downstream industry and slow transactions,rare earth market remained weak and price of rare earth products continued to decline.There was no sign of recovery in downstream market.The market of NdFeB magnetic materials and phosphor was depressed.Catalyst,     

New energy vehicle:an opportunity for rare earth magnets

<正>Extracted from Securities Guide 1.Popularity of new energy vehicles—an irresistible market trend1.1 Progress of new energy vehicles Chinese Premier Li Keqiang said recently on a visit to Xi'an BYD Autos that new energy vehicles,especially new energy bus,can lessen environment and noise pollution.He encouraged the use of new     

Brief news

正Corun invested another 50 million yuan in power battery for HEV Hunan Corun announced on 27 June that they had signed the cooperation agreement to jointly built Corun(Shaoxing)Autos Power Battery System Co.,Ltd.in Shaoxing Binhai New City.According to the announcement,total registered