磷石膏—磷渣基复合胶凝材料强度和水化特性研究

为实现磷石膏、磷渣固废材料的再生利用,提高工业固废的利用率,以磷石膏、磷渣作为主要原料,采用水玻璃、水泥熟料和磷石膏共同激发磷渣活性制备磷石膏—磷渣基复合胶凝材料。分别探讨磷石膏掺量、水玻璃掺量和磷渣粉磨制度对磷石膏—磷渣基复合胶凝材料强度的影响;并运用SEM、XRD分析磷石膏—磷渣基胶凝材料硬化体的微观结构及组成形貌。结果表明:磷石膏掺量低于50%时,复合胶凝材料各龄期强度与磷石膏掺量成反比;当m(磷石膏)∶m(磷渣)∶m(熟料)=20∶72∶8,水玻璃掺量为1.5%时,胶凝材料28 d抗压、抗折强度均达到最大值,分别为43、6.3 MPa;较单独粉磨磷渣与水泥熟料而言,混合粉磨制度会产生“微介质效应”,有利于提高复合胶凝材料强度;复合胶凝材料主要水化产物为C—S—H凝胶与钙矾石,钙矾石与未溶解的磷石膏作为骨架被生成的C—S—H凝胶包裹、充填、交织在一起,形成致密结构;复合胶凝材料用于替代水泥作为矿区充填材料时推荐磷石膏掺量为20%～40%。     

铁尾矿—磷渣—脱硫灰三元固废混凝土抗压性能研究

为实现铁尾矿固废材料的再生利用,提高工业固废利用率,以铁尾矿、磷渣、脱硫灰作为掺合料部分代替水泥制备混凝土,研究三元体系下钙相固废与铁尾矿协同作用对混凝土抗压强度的影响,测试不同水胶比、铁尾矿研磨时间、掺合料掺量及掺合料比例对混凝土抗压强度的影响。结果表明,混凝土抗压强度与水胶比呈正相关关系,机械研磨提高了铁尾矿的比表面积,有利于铁尾矿表面与自由水发生水化反应,30%掺量混凝土后期抗压强度较20%掺量下降不大,在铁尾矿比表面积为1 589.3 m²/kg,铁尾矿、磷渣、脱硫灰分别占胶凝材料的6%、16%、8%时制备的混凝土抗压强度最高,28 d抗压强度达到40.9 MPa。通过采用压汞法（MIP）和背散射电子成像技术（BSE）研究了混凝土的微观结构,结果表明,掺合料的掺入优化了混凝土的孔隙结构,促进了界面过渡区的发展。铁尾矿、磷渣、脱硫灰三元体系在30%掺量下对混凝土强度影响较小,可代替水泥制备混凝土。     

磷石膏基胶凝材料的试验研究

以未经处理的原状磷石膏为主要原料制备磷石膏基胶凝材料,通过微观分析及测试其力学性能,考察石灰掺量,水泥、粉煤灰比例及养护制度对磷石膏基胶凝材料力学性能的影响。结果表明:(1)该体系最优配比为磷石膏60%,水泥与粉煤灰比例为1∶4,生石灰4%,水料比0.25,减水剂0.2%;(2)该胶凝体系中磷石膏掺量超过60%后,抗压、抗折强度急剧下降;(3)蒸养制度对磷石膏基胶凝材料性能影响较大,在75℃下蒸汽养护10 h,基体强度增长较快且耐水性较高,28 d抗压强度为30.1 MPa,吸水率为8.5%,软化系数达到0.82。     

铁尾矿基多元体系抗压强度及水化特性研究

以铁尾矿、磷渣、脱硫灰为复合掺和料部分替代水泥，确定掺量为30%的情况下，考察复合掺和料不同配比对水泥砂浆试件抗压强度的影响，采用扫描电镜(SEM)和热重-差示扫描量热(TG-DTG)分析了水化产物数量及微观结构。结果表明，当铁尾矿、磷渣、脱硫灰质量比为1∶2∶2时强度最佳，7 d和28 d强度分别达到24.2 MPa和34.6 MPa。复合掺和料体系中，铁尾矿活性较低，主要起到微集料填充效应，使体系颗粒级配均匀；磷渣、脱硫灰中活性SiO₂、Al₂O₃可以通过二次水化反应进一步为体系提供强度，三者存在耦合效应，协同水化，生成水化硅酸钙(C-S-H)等水化产物促进强度提升。     

磷尾矿、磷石膏和黄磷渣的地质聚合反应资源化利用研究进展

随着磷矿开采量的增大,磷矿固废的库存量也逐年增加,对自然环境造成了严重的危害。概述了磷尾矿、磷石膏和黄磷渣固废资源的利用现状,以及碱激发地质聚合反应机理,对比了碱激发地质聚合物混凝土和普通硅酸盐水泥混凝土,阐述了通过碱激发地质聚合反应资源化综合利用磷尾矿、磷石膏和黄磷渣的现状。      

掺加磷尾矿煅烧水泥熟料的应用研究

分析了掺加磷尾矿对水泥熟料质量的影响,对不同掺量磷尾矿的水泥熟料进行易烧性、强度、岩相、XRD等测试.结果表明,磷尾矿的加入对生料易烧性有明显改善;掺量为2.5％时,熟料晶型形成较好,大小均匀,边棱清晰,中间相丰富;3d和28 d胶砂抗压强度达到了32.8 MPa和57.0 MPa,较空白样提高了5.1 MPa和3.3MPa.XRD图谱及TOPAS全谱分析也得出,掺加2.5％～ 5.0％磷尾矿有利于C3S以强度较高的M1型晶系存在,并对QS有稳定晶型的作用,但随着掺量的增加,又会阻碍C3S的形成,减少C3S的数量.     

基于磷石膏的多骨料充填体强度演化规律研究

针对湖北宜昌某磷矿重选尾矿产出量远远低于充填骨料需求量及磷石膏堆放造成环境污染的问题,在磷石膏及重选尾砂物理化学性质分析的基础上,进行了基于磷石膏和重选尾砂的多骨料配比试验,探究了不同养护龄期下充填体的强度演化规律;并利用电镜扫描(SEM)呈现了磷石膏胶结充填体的微观结构,揭示了磷石膏胶结充填体作用机理。研究结果表明:单独采用磷石膏作为骨料时,早期强度较低,添加重选尾矿可明显加快充填体的固结速度,同时充填体的早期及中期强度也相应增大,灰砂比1∶10、磷石膏∶重选尾矿为3∶2,质量浓度70%状态下,试块的7d强度可达1.35MPa,28d强度可达2.67 MPa。基于磷石膏和重选尾砂的多骨料充填体的早期强度增长平稳,增长较快,且强度较高,中期强度可达到后期强度的50%左右,多骨料充填体的强度增长相对稳定。     

贵州某磷渣矿物学特征及作水泥掺合料可行性研究

采用ICP-AES、XRD、SEM-EDS、FTIR等方法,对贵州某磷渣矿物学特征进行了研究,并考察了磷渣用作水泥掺合料时水泥的活性、凝结时间和标准稠度用水量。试验结果表明,磷渣掺量越大,水泥凝结时间越长,标准稠度用水量越高,活性指数越低。磷渣掺量为45%时,水泥的初、终凝结时间分别为502 min和572 min,满足GB 175-2007普通硅酸盐水泥凝结时间的要求;磷渣掺量为40%的水泥3 d的抗压、抗折活性指数均大于50%,满足GB/T 26751-2011规定的水泥和混凝土中的粒化电炉磷渣粉要求。     

磷化工固体废弃物综合利用技术现状

中国磷化工产业规模庞大,是我国国民经济发展的支柱产业,但在磷化工生产过程中每年会产生数千万吨的磷尾矿、磷石膏、磷渣等工业固体废弃物。目前,这些固体废弃物的堆积和消纳已经严重制约了我国经济的可持续健康发展,如何处理和利用这部分资源,对于整个磷化工产业的发展具有重要的意义。为了进一步了解我国磷化工固体废弃物综合利用技术现状,本文详细介绍了磷化工固体废弃物的产出、理化性质、堆存危害、处理技术,阐述了磷尾矿、磷石膏、磷渣三种典型磷化工固体废弃物在工业、农业、水泥、建筑等各个方面的综合利用技术现状,总结了我国磷化工固体废弃物现有利用技术中存在的综合利用率不高、产品转化处于初级阶段、没有实现资源全部循环利用等问题,最后针对未来磷化工固体废弃物处理发展路线,从技术可行性方面提出了合理化的建议,以期我国磷化工固体废弃物大量堆积现状能够得到有效改善,综合利用技术有所突破。     

电解锰渣复合胶凝材料的研制

利用电解锰渣和生石灰激发火山灰质材料粉煤灰的火山灰活性,制备电解锰渣复合胶凝材料.研究了电解锰渣和水泥对复合胶凝材料性能的影响,并在此基础上得出了最佳配合比,当电解锰渣复合胶凝材料中电解锰渣、粉煤灰、生石灰与水泥的质量比为50∶30∶ 10∶10,取水胶质量比为0.55,其28d抗折、抗压强度分别为2.50 MPa、10.05 MPa.     

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 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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Annual Report analysis of Chinese rare earth-related listed companies in 2013

<正>Chinese rare earth-related listed companies have published their 2013 annual reports.It can be understood from their reports that production and operation activities of Chinese rare earth-related companies were still heavily affected by macro economy and industrial policies.They basically followed the steps of national economy.In 2013,world economy recovered slowly but the economy     

Market opportunities and challenges for rare earth polishing powder

正1.Status of rare earth polishing powder Rare earth polishing powder with high content of cerium oxide began to replace iron oxide for glass polishing and became one of the key materials in glass polishing process since 1940.Compared with traditional iron oxide,rare earth polishing powder has many advantages,such as fast polishing rate,high polishing quality and long service life.It can achieve good surface quality and improve operation conditions.For example,in lens polishing,the polishing work that cerium     

Baotou Research Institute of Rare Earths developed a new RE alloy preparation technology

正Pyrometallurgy Laboratory of Baotou Research Institute of Rare Earths had independently developed a new preparation technology of rare earth alloy for NdFeB.The alloy can remarkably enhance the coercivity of NdFeB magnet but also evidently reduce the production cost of the magnet.The new master alloy was prepared in the kA pilot-scale electrolytic cell by the independent technology.The rare earth master alloy can be used as the raw material for NdFeB.Compared     

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.     

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.