硫酸铵焙烧活化石棉尾矿提取镁实验研究

本实验采用硫酸铵与石棉尾矿用高温炉焙烧的方法提取镁。首先利用差热-热重法分析石棉尾矿与硫酸铵混合物的热分解和化学反应的热效应,得出石棉尾矿与硫酸铵混合物在240~500℃下产生分解、失重。将石棉尾矿与硫酸铵混合均匀后在320℃、400℃和460℃下焙烧1h,用XRD分析焙烧产物,得出在320℃时石棉尾矿和硫酸铵反应主要生成(NH4)2Mg(SO4)2和(NH4)2Mg2(SO4)3;在400℃时主要生成(NH4)2Mg2(SO4)3;在460℃时主要生成MgSO4,由于吸水变为MgSO4.6H2O。研究了硫酸铵与石棉尾矿不同物质的量的配比、焙烧温度和焙烧时间对镁浸取率的影响,得出当硫酸铵与石棉尾矿物质的量之比为2∶1、焙烧温度为460℃、焙烧时间为60min时,镁的浸取率为83.1%。     

温石棉尾矿酸法焙烧产物提取氧化镁的研究

针对温石棉尾矿中提取MgO助剂消耗高、经济成本高等问题,采用浓硫酸和硫酸铵为混合酸性反应助剂,通过焙烧工艺提取温石棉尾矿中的MgO。优化工艺参数为：助剂中硫酸的摩尔比为80%;助剂（以SO42-计）与石棉尾矿（以MgO计）的摩尔比为1.2∶1;焙烧温度为350℃;保温时间为90 min,MgO的浸出率可达到83%~85%。适当增大酸性助剂中硫酸的摩尔比、助剂与温石棉尾矿物料比和温度可增大MgO提取率,而延长保温时间的效果不明显。TG-DSC与XRD分析表明,酸法焙烧温石棉尾矿反应过程主要分为3个阶段：第1阶段（136~253℃）纤蛇纹石与硫酸铵和硫酸反应生成中间产物(NH4)2Mg(SO4)2;第2阶段（253~324℃）残余的纤蛇纹石与(NH4)2Mg(SO4)2反应生成(NH4)2Mg2(SO4)3;第3阶段（324~400℃）(NH4)2Mg2(SO4)3分解,最终生成MgSO4。     

石棉尾矿焙烧活化制备建筑材料技术研究

以石棉尾矿为原料,采用不同焙烧助剂和焙烧工艺制备系列石棉尾矿焙烧产物,通过X射线衍射(XRD)和扫描电镜(SEM)分析,探究焙烧助剂种类、添加量、焙烧温度和时间等对焙烧产物结构、形貌及性能的影响。结果表明,焙烧温度为800℃,焙烧时间为2 h,焙烧助剂(NH₄)₂SO₄添加量为12%时,获得的样品胶凝性能最好;以该工艺条件制得的石棉尾矿焙烧活化产物为原料,加入不同比例水泥制成砌块试件,根据GB/T 4111-2013测试砌砖试件的各项性能指标,当水泥添加量为10%时,固化体抗压强度可达30 MPa,样品的抗压、抗冻、收缩率、吸水率等达到MU25免烧砖性能指标要求。     

煤泥尾矿活化增白实验研究

探究了煤泥尾矿的煅烧活化和增白条件,煤泥尾矿经过预处理成为合成分子筛等无机产品的原料,提高煤泥尾矿附加值。结果表明:采用盐酸对煤泥灰酸浸处理效果最好,采用炉内冷却比室温冷却对煤泥尾矿除铁效果好。通过单因素实验得到煤泥尾矿的最佳煅烧条件为:800℃煅烧2h,铁的浸出量为6.07%,铝的浸出量为17.96%,白度为85。正交试验分析表明,煤泥尾矿的最佳增白条件为:煅烧温度750℃,煅烧时间1h,粒度150μm。煤泥尾矿的最佳活化条件为:煅烧温度750℃,煅烧时间2h,粒度74μm。     

硫酸铵焙烧粉煤灰提氧化铝

采用硫酸铵焙烧法从粉煤灰中提氧化铝,通过单因素试验,研究了焙烧时间、焙烧温度和硫酸铵与粉煤灰质量比对氧化铝提取率的影响。正交试验结果表明,试验过程中各因素对氧化铝提取率的影响由大到小的顺序为:焙烧时间焙烧温度硫酸铵与粉煤灰质量比。最佳试验条件为硫酸铵与粉煤灰质量比为9∶1、焙烧温度为550℃、焙烧时间为60 min,氧化铝的提取率可达到81%。     

硫酸铵焙烧粉煤灰提铝

采用硫酸铵焙烧法从粉煤灰中提氧化铝,通过单因素试验,研究了焙烧时间、焙烧温度和硫酸铵与粉煤灰质量比对氧化铝提取率的影响。正交试验结果表明,试验过程中各因素对氧化铝提取率的影响由大到小的顺序为:焙烧时间>焙烧温度>硫酸铵与粉煤灰质量比。最佳试验条件为硫酸铵与粉煤灰质量比为9∶1、焙烧温度为550℃、焙烧时间为60 min,氧化铝的提取率可达到81%。     

硫酸铵焙烧钛渣提钛的研究

通过单因素试验,研究了焙烧温度、硫酸铵与钛渣质量比、原料粒度和焙烧时间对二氧化钛提取率的影响。正交试验结果表明试验过程中各因素对二氧化钛提取率的影响由大到小的顺序为:焙烧温度焙烧时间硫酸铵与钛渣质量比。得到最佳试验条件,即在硫酸铵与钛渣质量比为5∶1、焙烧温度为470℃、钛渣粒度为44~49μm,焙烧时间为80 min时,钛渣中二氧化钛的提取率可达到80%。     

温石棉尾矿活化产物酸浸渣碱浸取率实验研究

温石棉尾矿燃烧活化产物酸浸渣的主要化学成分为无定形二氧化硅,由于受到煅烧的作用,温石棉尾矿中硅氧架状结构受到破坏,生成更多的化学断键,增大了其活性.采用NaOH浸取其中的二氧化硅,研究NaOH浓度、反应时间、反应温度、液固比及粒度大小对碱浸取率的影响,并与未煅烧的温石棉尾矿酸浸渣碱浸取率进行对比.结果表明,最佳实验条件...     

云锡脉锡型尾矿预先抛尾—焙烧回收锡、铁研究

以云锡脉锡型尾矿粗粒部分为研究对象,通过正交试验研究了焙烧温度、焙烧时间、还原剂种类和用量对尾矿焙烧的影响,确定了影响焙烧的主要因素和最佳工艺条件。试验结果表明,在最佳工艺条件下,即焙烧温度为973K,焙烧时间为20min,无烟煤用量为5%时,可获得品位和回收率分别为64.17%和68.55%的铁精矿以及9.12%和30.54%的锡精矿。     

白云鄂博稀土尾矿酸浸渣制备白炭黑

以白云鄂博稀土尾矿酸浸渣作为原料进行了制备白炭黑的可行性试验,试验分别对硅浸出过程中的焙烧温度、时间以及焙烧药剂用量进行了研究。试验结果表明：以白云鄂博稀土尾矿酸浸渣和NaOH为原料,在熔盐体系下700 ℃煅烧2 h,酸浸渣中的SiO₂浸出率达93%以上;用X射线衍射仪、红外光谱仪对所制白炭黑的分析表明,所制备的白炭黑为无定型的水合二氧化硅。     

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     

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     

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     

唐口煤矿深部复杂开采工作面瓦斯分源涌出规律研究

研究工作面瓦斯涌出规律对工作面瓦斯治理有重要意义。为了得到唐口煤矿深部3号煤层复杂开采条件下工作面回采时期瓦斯涌出时空演化规律,选取6304工作面作为对象,采用实测方法研究6304工作面瓦斯涌出规律。结果表明:6304工作面瓦斯涌出量为6.534 m³/min,其中煤壁占34.27%,落煤占29.62%,采空区占36.11%;沿工作面倾向由低到高,瓦斯浓度整体为上升趋势,其中1—76号架工作面瓦斯浓度小于0.20%,76—102号架瓦斯浓度上升明显,最大为0.387%;上隅角的后部采空区是工作面的瓦斯主要涌出源,上隅角1号测点瓦斯浓度0.78%,上隅角周边3号、5号、7号、8号、9号测点瓦斯浓度平均为0.643%;周期来压时,上隅角瓦斯相对平时较高。研究为针对性的瓦斯分源监控与灾害防治提供基础。