离子型稀土矿区土壤中高岭土对氨氮的吸附研究

我国南方离子型稀土矿区土壤氨氮污染严重,高岭土是矿区土壤的主要黏土成分之一。本文对高岭土黏土矿物与氨氮污染间的吸附特点及吸附动力学等进行了研究。结果表明:随着氨氮初始浓度、温度的升高,高岭土对氨氮的吸附量与吸附速率均提高;pH9.2时,高岭土对氨氮的吸附量随pH值增大而增大;pH9.2时,二者间的吸附量随pH值增大急剧降低;高岭土对氨氮的等温吸附符合Langmuir模型和Freundlich模型,吸附动力学符合准二级动力学方程;对于实际的我国南方的离子型稀土开采矿区,在矿区土壤的温度存在主要区间(298~310K)、pH值存在范围(3.0~6.0)内,随原地浸矿时温度、浸矿液浓度或pH值的升高,矿区土壤中氨氮的吸附残留量均会增大;可通过使用较低浓度的原地浸矿液、控制较低的土壤pH值和温度,加强对矿区污染土壤中氨氮的去除。     

粘土矿物对废水中Cu~(2+)、Cd~(2+)、Cr~(3+)的吸附实验研究

采用膨润土和高岭土对重金属的吸附性能进行了实验研究。结果表明:pH对吸附效果有明显影响,当pH值增大时,膨润土和高岭土对重金属的吸附量也随之增大。初始浓度相同的情况下,蒙脱石对重金属的吸附大于高岭土,而且都是随初始浓度的增加而增大。蒙脱石和高岭土对三种不同的重金属离子的吸附能力的强弱都是Cr>Cu>Cd,用Langmuir吸附方程式对吸附等温线进行拟合,相关系数达到0.98以上。     

电解质对低阶煤油泡浮选矿化过程的影响

浮选矿浆中离子的种类与浓度直接影响着矿物颗粒和气泡的表面电位,进而支配着浮选矿化过程。从热力学和动力学两个方面入手,通过DLVO理论探究了不同电解质对煤粒和油泡间的相互作用势能的影响,结合其在不同电解质条件下诱导时间的差异,最终通过相应条件下的油泡浮选试验来证实电解质对低阶煤-油泡浮选矿化黏附过程的影响。结果表明:对于NaCl和CaCl_2两种电解质,随其浓度的增大,煤粒和油泡表面电位的负值均不断减小,煤粒和油泡间的能垒也不断降低,当CaCl_2浓度为100 mmol/L时,煤粒和油泡间的相互作用不存在能垒;并且随这两种电解质浓度的增大,黏附过程的诱导时间逐渐减小,相应地可燃体回收率不断提高,且相同的电解质浓度下,CaCl_2电解质对其相互作用能垒和诱导时间的降低程度更大,可燃体回收率更高。而对于AlCl_3电解质,当其浓度大于20 mmol/L时且随浓度的增大,煤粒和油泡间的相互作用能垒和诱导时间不断增大,相应地可燃体回收率则不断降低。     

微细粒赤铁矿磁复合絮凝行为研究

以赤铁矿纯矿物作为研究对象,通过沉降试验来考察磁场和絮凝剂联合作用对赤铁矿絮凝沉降行为的影响。结果表明:通过磁场和絮凝剂的联合作用,沉降效果明显优于单一的高分子絮凝和磁絮凝。对复合体系中赤铁矿颗粒间总作用势能进行计算,计算结果表明磁场和絮凝剂的联合作用降低了复合体系中的势能垒,利于赤铁矿颗粒间的聚团。     

酸改性高岭土对Cr(Ⅵ)印染废水的吸附性能研究

通过电子扫描电镜(SEM)、傅立叶变换红外光谱(FTIR)表征酸改性高岭土,并分别研究了平衡时间、高岭土用量、pH值对Cr(Ⅵ)在酸改性高岭土上吸附性能的影响.结果表明,酸改性高岭土对Cr(Ⅵ)具有较强的吸附能力,在Cr(Ⅵ)初始浓度为9.375×10-3 g/L的情况下,4h时达到吸附平衡;高岭土浓度在0.75 g/L时,吸附效果好;Cr(Ⅵ)在膨润土上的吸附受pH值影响较大,pH值在6.0～7.0时去除率达到最大值95.5％.高岭土对Cr(Ⅵ)的吸附等温线表明,高岭土吸附能力随着温度的升高而增大,其吸附是吸热过程.     

磁化处理对微细粒赤铁矿絮凝的影响

以赤铁矿纯矿物作为研究对象, 通过沉降试验来考察不同方式的磁化处理作用对赤铁矿絮凝沉降行为的影响。结果表明:矿浆和药剂在经过磁化处理后, 絮凝效果明显优于未经过磁化处理的絮凝效果, 且磁场强度越高絮凝效果越好; 在矿浆磁化和药剂磁化为60 min时赤铁矿沉降率达到最大值, 分别为73.9%和72.7%, 磁化矿浆比磁化药剂对赤铁矿絮凝的效果好; 磁化矿浆和磁化药剂两种不同磁化处理方式下的赤铁矿颗粒Zeta电位测量结果表明, 磁化处理会改变赤铁矿颗粒的Zeta电位, 分别从-50.765 mV减小至-43.538 mV和-44.006 mV; 磁化处理降低了赤铁矿颗粒间双电层排斥力, 降低颗粒间的势能垒, 使赤铁矿颗粒更易于聚团, 絮凝效果增强; 赤铁矿与淀粉红外光谱研究结果表明, 赤铁矿与淀粉分子间存在着化学吸附和氢键作用。      

酸改性高岭土对Cr(VI)印染废水的吸附性能研究

通过电子扫描电镜(SEM)、傅立叶变换红外光谱(FTIR)表征酸改性高岭土,并分别研究了平衡时间、高岭土用量、pH值对Cr(VI)在酸改性高岭土上吸附性能的影响.结果表明,酸改性高岭土对Cr(VI)具有较强的吸附能力,在Cr(VI)初始浓度为9.375×10~(-3 )g/L的情况下,4 h时达到吸附平衡;高岭土浓度在0.75 g/L时,吸附效果好;Cr(VI)在膨润土上的吸附受pH值影响较大, pH值在6.0～7.0时去除率达到最大值95.5%.高岭土对Cr(VI)的吸附等温线表明,高岭土吸附能力随着温度的升高而增大,其吸附是吸热过程.     

弱磁性矿物颗粒在外磁场中的疏水絮凝

本文讨论了外磁场中弱磁性矿物粒子的疏水絮凝现象，作者称之为复合絮。试验结果表明，它比单一的疏水絮凝和磁絮凝强烈得多，作者对外磁场中诱导菱锰矿疏水颗粒间总作用势能进行了计算，并讨论了外磁场中疏水絮凝的影响因素。计算结果表明，单一的外磁场不能形成强烈絮凝，它可以强化疏水絮凝过程，外磁场的作用在于减小以至消除疏水颗粒间总相互作用势能的能垒，从而使絮团过程更容易产生，这正好与试验结果相吻合。     

微细粒鲕状赤铁矿磁化絮凝行为与机理研究

为提高赤铁矿絮凝浮选指标，分别采用磁化水、磁化矿浆和磁化淀粉3种磁化方式对赤铁矿进行絮凝沉降，考察磁处理方式对絮凝效果的影响。结果表明，3种磁化方式均能提高鲕状赤铁矿絮凝沉降率。光学显微镜分析结果显示，经过磁化处理后的絮团较未磁化时表观粒径更大，结构更加紧密，同时观察到絮团周围分散着透明的石英颗粒，说明磁化处理能够显著促进微细粒赤铁矿选择性絮凝。在磁化水、磁化矿浆和磁化淀粉3种磁化方式作用下赤铁矿颗粒表面ζ电位均随着磁化时间的增加而降低，ζ电位的变化趋势与鲕状赤铁矿在不同磁化条件下沉降率的变化规律一致。3种磁化方式对微细粒赤铁矿的絮凝过程符合扩展的DLVO理论，其絮凝机理为：磁化处理能在不同程度上降低赤铁矿颗粒表面ζ电位，进而降低了微细粒赤铁矿颗粒间的双电层排斥力，降低了颗粒间的势能垒。     

微生物絮凝剂絮凝机理的初步研究

通过絮凝实验和高岭土表面zeta电位测定,初步研究了agrobacteriumradiobacter菌产生的絮凝剂的絮凝特性和絮凝机理,结果表明阳离子Ca2+、Al3+、Fe3+通过中和高岭土表面的负电荷和增加微生物絮凝剂在高岭土颗粒表面的吸附而促进微生物絮凝剂的絮凝性能;在pH2.0~10.0范围,微生物絮凝剂均有良好的絮凝活性,并且加入微生物絮凝剂后,高岭土的zeta电位曲线下移,表明它对高岭土的絮凝作用不是以电中和为主的,而是以吸附架桥为基础的;不同温度条件下(40~100℃)加热30min,絮凝活性变化很小,表明微生物絮凝剂是表面带阴离子的具有热稳定性的多聚糖类生物大分子,而不是对热敏感的蛋白质类物质,同时紫外扫描光谱也证明了该絮凝剂中不含蛋白质类成分和核酸。     

Market and recycling of NiMH battery

<正>Market status and future trend of NiMH battery1.Global market of small NiMH battery Global market size of small NiMH batteries declined year on year since 2011.The trend will continue to 2018,at the rate of 5%to 10%annually.Demand for small NiMH batteries will be stable gradually.Many electrical apparatuses are powered by the built-in lithium battery today,which is the main reason for the shrunk market of small NiMH batteries.But,for some products,small NiMH     

China rare earth market review

正September 1-10,2014 Affected by the National Day holiday,rare earth transaction was stagnant and the market showed a weak steady state.As there was no good news for downstream market,some products with flat demand would likely rally slightly for some time to     

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     

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.     

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.     

Current situation and future trend of China rare earth luminescent material industry

<正>Rare earth luminescent material is one of the most important application sectors of rare earths.China enjoys the exceptional advantage to develop rare earth luminescent material for its abundant rare earth resources.After several decades'endeavor,China's rare earth luminescent material industry,headed by rare earth phosphor for lamp and LED and high efficient rare earth energy-saving light source,has been gradually developed into a scale industry.China has become a major production base of rare earth phosphor for lamps and rare earth     

China rare earth market review

正June 1~10,2014Rare earth market remained weak.Quoted price of rare earth products was similar to that in May.There was no sign of recovery in downstream market.The market of NdFeB magnetic materials and phosphor was depressed.Catalyst,polishing powder and ceramic industries remained inactive.Demand from downstream industry was soft.Consumers purchased on their needs.Suppliers had strong intention to sell.Prices of rare earth products     

2014 second batch of rare earth quota released

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