工艺条件对制备超细氢氧化镁性能的影响

以菱镁矿为原料,经低温煅烧得到轻烧氧化镁,采用水化法制备氢氧化镁超细粉体.论文研究了水化温度、添加剂对水化产物颗粒大小的影响.利用XRD和SEM对合成氢氧化镁晶体特征、颗粒大小和形貌进行了表征.结果表明,制备的超细氢氧化镁为片状颗粒,颗粒大小约为200nm.     

石棉尾矿综合利用研究进展

石棉尾矿是一种以蛇纹石为主要矿物成分的尾矿，对矿区环境危害严重。本文介绍了石棉尾矿的基本物化性质并综述了国内外近年来对石棉尾矿综合回收利用的研究工作。指出利用石棉尾矿制备高纯超细氢氧化镁和高纯超细高比表面积白炭黑是一种技术上可行、经济效益明显的路线并介绍了相关研究成果。     

水热法制备超细氢氧化镁

以水镁石为原料,通过煅烧,制得氧化镁粉末,然后将氧化镁和尿素碱溶液反应,通过氧化镁水合法制备出了超细氢氧化镁颗粒,同过利用X-射线衍射仪(XRD)和扫描电子显微镜(SEM)对所制得氢氧化镁颗粒的晶相、形貌和颗粒尺寸进行了表征。试验结果表明,溶液浓度和添加剂对氢氧化镁晶体的晶相和颗粒尺寸有显著的影响,当溶液浓度为2.5 mol/L,添加剂为PEG 6000的情况下,制备出了半径为250 nm,片厚约150 nm,晶形完整,大小均一的六方片形超细氢氧化镁颗粒,但是样品的纯度有待于进一步的提高。     

油页岩半焦合成多孔托贝莫来石晶体的研究

以油页岩半焦为原料采用水热合成法制备多孔托贝莫来石晶体。采用XRD、SEM、N2吸附脱附实验等方法探讨了晶化温度、晶化时间、残余碳组分对合成托贝莫来石晶体物相、孔特征等性能的影响。XRD实验结果表明:通过加入Ca O、Na OH水热助剂在晶化温度220℃、晶化时间7 h条件下可合成结晶良好的托贝莫来石晶体;油页岩半焦中残余碳组分在反应早期有利于托贝莫来石晶体的形成。SEM结果表明:水热合成的托贝莫来石晶体呈片状或针状,残余碳组分的存在阻碍托贝莫来石晶体的长大及团聚,增加了托贝莫来石结晶体的比表面积和孔径,这有利于托贝莫来石晶体作为吸附剂的吸附性能。比表面积实验结果表明利用油页岩半焦为原料合成的多孔托贝莫来石比表面积达到76.3 m2/g。     

石灰乳法制备大粒径氢氧化镁研究

以卤水和石灰乳为原料,研究了温度、进料速度及氯化钙浓度对氢氧化镁颗粒大小的影响。通过比表面积分析仪(BET)、扫描电镜(SEM)和X射线衍射仪(XRD)对产物的比表面积、形貌及晶体生长方向进行表征。结果表明,氯化钙的加入对氢氧化镁晶体生长方向有较大影响,颗粒更倾向于沿着极性较弱的(001)面方向生长;当氯化钙浓度为16 mol/L,石灰乳和卤水浓度分别为2 mol/L、4 mol/L,反应温度90℃,进料速度0.11 m L/min时,比表面积降到8.56 m2/g,与未加入氯化钙比较,氢氧化镁的粒径明显变大。     

表面活性剂对TiOSO_4常温水解法制备纳米TiO_2粉末的影响

论述了聚乙二醇在TiOSO4 常温氨水水解反应制备纳米TiO2 粉末中的作用 ,并对不同制备条件及热处理温度下的纳米TiO2 粉末结构、粒径大小和比表面积进行了表征。讨论了水解时聚乙二醇的加入与否和煅烧条件对纳米TiO2 粉末的团聚作用 ,以及对晶型转变温度、粒径大小、比表面积等因素的影响。结果表明 :水解时加入聚乙二醇制得的纳米TiO2 粉末团聚作用小 ,颗粒为球形 ,平均粒径为 7.4nm ,平均比表面积为 1 1 6.5 5m2 /g ,最高比表面积达 1 60 .92m2 /g。     

石棉尾矿综合利用中试技术研究

以石棉尾矿为原料,采用酸浸、氧化除铁、控制碱析Mg(OH)2以及酸浸渣碱溶、稀酸法控制沉析SiO2工艺,并在碱析和稀酸沉析过程中适时添加表面处理剂和粒径控制剂,制备了超细Mg(OH)2和超细高比表面积SiO2.中试主要产品的技术指标为:①超细氢氧化镁,d50=1.0±0.2μm,Mg(OH)2=98±0.5%,白度＞92.0%;②超细二氧化硅BET比表面积1900～479m2/g,孔体积0.47～1.01cm3/g,平均孔径30～80A,干基SiO2含量为≥99%,白度≥93.0%;③产出率(以加工1000kg尾矿计),超细氢氧化镁≥420kg,超细高比表面积二氧化硅≥310kg,尾矿中氧化镁和二氧化硅的回收率在80%以上.     

外力环境对氧化镁水化产物性能的影响

为解决氢氧化镁制备过程中存在的周期长、产品纯度低、形貌团聚等难题，探究了水化效果最佳的氧化镁活性条件，并在无外力、搅拌和超声三种环境下分别进行75 ℃，2 h常压水化反应制取氢氧化镁，分析了产物的纯度、形貌及粒度分布规律。结果表明：比表面积为4.59 m2/g的氧化镁原料水化速率适中，所得产物为主要为0.5~3.5 μm细颗粒，且最大体积含量高达12%，仅存在少量100~130 μm的大颗粒，在水化速率和产品粒度上均最佳。但无外力作用时水化产物纯度不够，氢氧化镁含量仅为35.6%，含有大量氧化镁杂质，团聚现象严重，产物粒度分布范围大，颗粒尺寸不均更是证实存在团聚现象；在搅拌作用下虽加快了水化反应，使氢氧化镁含量提高至55.9%，但加剧了氢氧化镁的团聚，使粒度变粗；超声作用克服了氧化镁的团聚问题，由于团聚现象微弱，氧化镁完全裸露在反应液中，加快反应速率的同时，也实现了氧化镁100%的转化率，保证了产品纯度和粒度，提高了产品分散性。     

超细氧化铝粉制备的研究

采用沉淀法制备超细氧化铝粉,通过添加表面活性剂控制颗粒的大小、共沸蒸馏处理有效地消除氟氧化铝凝胶的硬团聚,制得了平均粒度为ｄ５０＝０．４７ｕｍ、比表面积ＢＥＴ－４．５５６０ｍＴ＾２／ｇ的超细粉末。     

石棉尾矿高效综合利用技术研究

以甘肃阿克塞矿区的石棉尾矿为原料,采用酸浸、氧化除铁、控制碱析Mg(OH)2以及酸浸渣碱溶、稀酸法控制沉析SiO2工艺,并在碱析和稀酸沉析过程中适时添加表面处理剂和粒子阻隔剂,制备了超细Mg(OH)2和超细高比表面积SiO2。中试产品的主要性能指标为:①超细氢氧化镁:中位粒径(d50)1.0±0.2μm; MgO=67±0.5%,白度>92.0;②超细高比表面积二氧化硅:BET比表面积384～479m2/g ,孔体积0.47～1.01cm3/g ,平均孔径30～80A,干基SiO2含量为≥99%,白度≥92.0。平均产出率(以加工1t尾矿计):超细氢氧化镁357kg,超细高比表面积二氧化硅326kg,尾矿中MgO和SiO2组分的回收率达到80%以上;处理1t石棉尾矿可获利1 000元以上。。     

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