壳聚糖改性膨润土及其对水中Pb2+的吸附性能

用壳聚糖改性膨润土,制备了一系列不同原料配比的改性膨润土,运用扫描电镜、红外光谱和X-衍射对其结构进行表征,表征结果表明,壳聚糖吸附在膨润土的表面,形成了复合吸附剂.考察了壳聚糖改性膨润土对水中Pb2+吸附性能,通过单因素影响吸附实验,确定了壳聚糖改性膨润土吸附水中Pb2+的适宜反应条件.实验结果表明:当Pb2+初始浓度为20mg/L时,膨润土和壳聚糖质量比为1︰0.01,反应时间为45min,pH值为5.5,吸附剂用量为1g/L,Pb2+去除率达到90%以上.与膨润土相比,吸附性能得到了很大的提高.运用Langmuir和Freundlich方程对该吸附过程进行拟合,吸附行为符合Langmuir和Freundlich吸附等温式.经多次再生,吸附容量基本不变.通过计算不同温度下各热力学参数△G,△H,△S的值,表明该吸附过程是一个自发的吸热过程.     

有机膨润土吸附丁基黄药试验研究

以钠基膨润土为原料制得有机膨润土,采用红外光谱对有机膨润土进行表征。研究了有机膨润土用量、吸附时间、温度及p H值对有机膨润土吸附丁基黄药效果的影响,并结合吸附动力学模型研究有机膨润土对丁基黄药的吸附特性。结果表明,在有机膨润土用量为1.4 g/L,p H值为9,温度30℃,吸附时间20 min时有机膨润土对黄药的吸附率为96.06%,且有机膨润土对丁基黄药的吸附过程更适合采用二级吸附动力学方程进行描述。     

天然膨润土对Cr(Ⅵ)的吸附动力学及等温线研究

研究所用膨润土的主要成分为SiO2和Al2O3,属于钙基膨润土,BET比表面积为47.98 m2/g。在恒温及恒定pH条件下,用动态吸附法研究了膨润土对Cr(Ⅵ)的吸附特性,结果表明其较好符合Lagergren二级吸附速率方程。利用Langmuir等温线方程和Freundlich等温线方程对动态吸附过程进行拟合,发现其吸附等温反应与Langmuir等温线更适合,属于表面单分子吸附。     

有机膨润土制备及其对Cr（Ⅵ）吸附性能研究

以内蒙古固阳钙基膨润土为实验材料,在提纯和钠化的基础上,以十六烷基三甲基溴化铵(CTMAB)作为有机改性剂,对制备的钠基膨润土进行有机改性.通过正交实验,得到制备有机膨润土的优化工艺条件为:pH值为2,温度60℃,改性剂用量13mmol/10g土.实验结果表明,有机膨润土对水溶液中Cr(Ⅵ)的去除率较钠基土有显著提高,有机膨润土吸附Cr(Ⅵ)符合Freundlich等温吸附方程.     

酸改性膨润土对废水中铬的吸附性能研究

以硫酸为改性剂,对膨润土进行活化改性,考察了膨润土原土及酸改性膨润土用量、吸附时间以及pH值等因素对其处理低浓度含Cr6+废水的影响.结果表明,在35℃下,当改性膨润土用量为0.8 g/100mL,吸附时间为40 min,pH值在2以下时,对废水中Cr6+(1 mg/L)的吸附效果较好,吸附量可这0.047 mg/g.改性膨润土吸附Cr6+的动力学数据满足准二级动力学方程.     

膨润土负载壳聚糖对水中Cu(II)的吸附特性研究

通过水热振荡法制备了膨润土-壳聚糖复合吸附剂,并对废水中铜(Cu(II))进行吸附。通过傅立叶变换红外光谱(FT-IR)和扫描电子显微镜(SEM)对复合吸附剂进行了表征。研究结果表明,膨润土-壳聚糖复合吸附剂对铜的吸附性能优于单一膨润土。与膨润土相比,膨润土-壳聚糖复合吸附剂的形状不规则,表面粗糙疏松。在Cu(II)初始浓度为50 mg/L、pH值为7、吸附温度为30℃、接触时间为15 min的条件下,膨润土-壳聚糖复合吸附剂对Cu(II)的去除效率可达95%以上,吸附量可达到20.12 mg/g。此外,Langmuir和Freundlich模型都能很好地拟合Cu(II)在两种吸附剂上的等温吸附。膨润土壳聚糖复合吸附剂对Cu(II)的吸附过程符合准二级动力学方程。     

钠基膨润土对重金属离子Cu2+， Zn2+，Cd2+ 的吸附实验

通过等温吸附试验,研究了钠基膨润土对不同浓度的Cu²⁺,Zn²⁺,Cd²⁺的吸附情况,结果表明,钠基膨润土对Cu²⁺,Zn²⁺,Cd²⁺有很好的吸附作用,等温吸附曲线符合Langmuir 方程,吸附容量随金属离子浓度的增加而增大,并趋于平稳,通过吸附实验发现钠基膨润土对重金属离子的吸附具有选择性,吸附容量的大小顺序为Cu²⁺＞Zn²⁺＞Cd²⁺.研究表明,钠基膨润土是一种良好的土壤改良剂,可降低土壤中重金属的有效性,且不产生二次污染.     

多孔有机膨润土颗粒研制及对PO4^3-的吸附研究

将易燃微粉按一定比例混入膨润土中，挤压造粒，高温灼烧，再用阳离子表面活性剂改性．得到多孔有机膨润土颗粒。将其用于对PO4^3-离子的吸附，研究了酸度、吸附时间、PO4^3-离子的初始浓度对吸附反应的影响．指出该吸附过程符合Langmuir吸附等温方程。     

微波-CTMAB膨润土吸附除磷的动力学和热力学研究

通过静态实验,考察了在不同反应时间和温度条件下,原膨润土(OB)、CTMAB改性膨润土(CTMABB)以及微波-CTMAB协同改性膨润土(MCTMABB)对pO43-吸附效果的影响;对3种材料除磷的吸附动力学、吸附速率控制步骤以及吸附热力学模型进行了拟合并计算出相应参数.结果表明,吸附反应15min (25℃),OB、CTMABB及MCTMABB对PO43-的吸附基本达到平衡,其吸附容量分别达到2.27、3.50和4.88 mg/g.伪二级动力学方程可以很好地描述3种材料对PO43-的吸附(R2＞0.99);Elovich方程中的a值大小表现为:αOB＜aCTMABB＜aMCTMABB,表明膨润土经CTMAB和CTMAB-微波协同改性后其对PO43-的吸附效率依次增强.3种材料对PO43-的吸附反应均受液膜扩散和颗粒内扩散2个步骤控制.3种材料对PO43-的吸附反应均是自发的放热反应,温度升高均不利于3种材料对PO43-的吸附.     

天然膨润土对Cr(VI)的吸附动力学及等温线研究

研究所用膨润土的主要成分为SiO₂和Al₂O₃,属于钙基膨润土,BET表面积为47.98 m₂/g。在恒温及恒定pH条件下,用动态吸附法研究了膨润土对Cr(VI)的吸附特性,结果表明其较好符合Lagergren二级吸附速率方程。利用Langmuir等温线方程和Freundlich等温线方程对动态吸附过程进行拟合,发现其吸附等温反应与Langmuir等温线更适合,属于表面单分子吸附。     

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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