利用粉煤灰漂珠合成莫来石的研究

用粉煤灰漂珠直接制备M45莫来石以及与工业纯氧化铝混合合成M70莫来石,可明显降低合成成本.采用综合热分析仪(TG-DSC)、X-射线衍射仅(XRD)和扫描电子显微镜(SEM)对样品进行表征.结果表明:用预处理后的粉煤灰漂珠直接制备低牌号莫采石(M45),适宜的烧结温度为800℃;用预处理后的粉煤灰漂珠和工业氧化铝混合制备高牌号莫来石(M70),适宜的烧结温度为900℃;合成的莫来石的主要组分符合我国<烧结莫来石>标准(YB/T5267-2005).     

以煤矸石为原料制备堇青石-莫来石复合材料

以煤矸石、菱镁矿、高岭土为原料,采用原位反应烧结法制备堇青石-莫来石复合材料,研究烧结温度和保温时间对堇青石-莫来石复合材料的物相组成、显微结构、物理性能的影响。结果表明,适当提高烧结温度和延长保温时间,可促进堇青石和莫来石晶体的合成,使试样显气孔率下降,致密度提高,耐压强度增大,但温度过高或保温时间过长不利于堇青石相的生成,使试样体积密度和耐压强度均有所降低。烧结温度为1 350℃,保温时间为2 h时,试样内部堇青石晶体和莫来石晶体发育良好,显气孔率为33.61%,体积密度为1.795 g/cm3,耐压强度为63.12 MPa,性能最优。     

锆英石原位合成氧化锆——莫来石复相材料的研究

通过锆英石与α-Al2O3、γ-Al2O3和Al(OH)3之间的原位反应制备了氧化锆—莫来石复相材料,采用XRD、SEM和EDS等手段研究了合成温度、铝源种类对氧化锆—莫来石复相材料物相组成、显微形貌和性能的影响,探讨了锆英石和不同铝源之间原位反应合成氧化锆—莫来石复相材料的烧结机制。结果表明:原位反应合成氧化锆—莫来石复相材料的优化反应温度为1 600℃,优化氧化铝源为α-Al2O3,可获得高致密度的氧化锆—莫来石复相材料。     

合成莫来石的生产

据美刊《工业矿物》报道合成莫来石主要以三种形式产出,即烧结莫来石,电熔莫来石和电熔氧化锆莫来石.消耗和生产均维持在相对小的规模,可能一年仅为数万吨.只有欧洲、北美、南美和日本的少数生产厂家在进行生产.合成莫来石的主要用途是作耐火材料,两个主要市场是炼钢工业和玻璃     

高温烧结条件下蓝晶石的莫来石化

采用两种不同粒度的蓝晶石为主要原料,加入不同数量的轻烧高铝矾土,并分别于1600℃和1650℃下烧结,研究讨论所得试样的烧结性能。试验结果表明:提高铝硅比可以降低莫来石形成的起始温度;适当提高合成温度,可使莫来石含量提高,气孔率降低,体积密度增加。     

粉煤灰用于制备莫来石-SiC材料的实验研究

利用粉煤灰、铝矾土、碳化硅为原料，在1450℃下烧结制备了莫来石-SiC复合材料，采用XRD、SEM等手段研究了莫来石～SiC复合材料的性能、物相和显微形貌。结果表明：当混合料M（其中Al／Si=1．0，摩尔比）=10％，所得材料的显气孔率、吸水率最小，分别为16．09％和6．27％，抗折强度和体积密度最大，分别为46．7MPaN2．57g／cm^3此时，构成材料的主要晶相为SiC、莫来石和刚玉，莫来石的相对含量达到最大值，为38．99％。SEM分析表明，生成的莫来石和刚玉镶嵌在SiC中间，当M=10％，莫来石呈现网状小球体的形态。     

硅线石合成莫来石研究

以硅线石精矿为原料，添加高铝矿物，可人工合成莫来石，本试验确定了人工合成莫来石的工艺流程和工艺参数，进行了烧结温度，保温时间，Ａｌ２Ｏ３含量，磨矿粒度等对合成莫来石的影响试验。所获产品莫来石含量为９３．５％，刚玉５％，玻璃相微量，具有良好的物理化学性能。     

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。     

低品位锂辉石对铝矾土尾矿制备莫来石基复相陶瓷的影响

在铝矾土尾矿减量消纳利用制备陶瓷材料的基础上,探究低品位锂辉石的助熔作用对制备莫来石基复相陶瓷的影响。在配料—混料—干燥—成型—烧结的制备工艺过程中外加低品位锂辉石,探究外加剂含量(0%、2%、 5%、10%)和烧结温度(850、900、950 ℃ )对莫来石基复相陶瓷物相行为、显微形貌和力学性能的影响规律。 结果表明,经低温烧结制得莫来石基复相陶瓷的主要物相为石英、莫来石、刚玉,提高烧结温度在热力学和动力学方面均有利于莫来石的形成;锂辉石的助熔作用可增加试样中的莫来石和刚玉等优质耐高温物相,在微观形貌上起到支撑骨架作用,有利于提高试样的力学性能;外加 10%低品位锂辉石时,在 950 ℃ 温度下保温 2 h 获得试样的常温抗压强度为 47. 0 MPa、体积密度为 1. 77 g / cm³。     

铝土矿尾矿烧结合成莫来石反应热力学计算与试验验证

在综合分析铝土尾矿物相组成基础上,基于多相平衡反应热力学原理,分析评价直接高温烧结莫来石的反应过程。结果显示,在1 100℃下,硬水铝石、高岭石等物相之间即可反应;1 600℃下,尾矿烧结过程需消耗标煤约214.7kg/t。烧结试验结果表明,在1 100℃下烧结,铝土尾矿即可反应生成莫来石,并出现中间产物刚玉、方石英与少量赤铁矿;优化烧结温度为1 600℃,最终产物的物相组成为:莫来石89.8%,铁板钛矿7.3%,硅酸钙2.3%,与计算结果相一致,其可作为生产硅莫砖原料使用。     

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     

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     

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     

2014 second batch of rare earth quota released

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矿用防爆轴流对旋主要通风机叶片ANSYS模态分析及应用

高效节能矿用防爆对旋主要通风机的叶片是主要通风机运行的关键部件,叶片在运行时不断受到气流的作用力,从而使叶片产生振动,当叶片振动的频率与叶片的固有频率接近时,容易产生共振从而导致叶片的断裂。一旦叶片断裂时,对主要通风机的安全运行产生致命的影响,从而导致矿山、化工等企业发生重大事故,将会产生不可估量的损失。基于有限元分析软件ANSYS,对高效节能矿用防爆轴流对旋主要通风机叶片进行模态分析及产生对应的六阶模态频率,对主要通风机叶片的运行频率、固有频率及产生的共振问题进行了原理分析,并且解决了叶片频率共振的问题,从而为主要通风机叶片结构设计提供理论依据,并对主要通风机叶片的安全运行提供保障。     

2013 NdFeB export analysis

<正>China totally exported nearly 24,000 tonsof NdFeB products during 201 3,including 18,825 tons of permanent magnet,valued USD 1.34 billion at an average price of 71.4 USD/kg;3,277 tons of NdFeB magnetic powder,valued USD 1 01 million at an average price of 30.9 USD/kg;1,334 tons of strip casting ribbon,with total export value of USD 74million at an average price of 55.3 USD/kg;and 586