赤泥中硫酸选择性浸出铁、钪及动力学研究

以硫酸为浸出剂,进行了酸浸初步分离铁、钪的研究,考察了反应时间、反应温度、液固比、硫酸浓度等对浸出率的影响。结果表明,在40 ℃、液固比10∶1、硫酸浓度10 mol/L条件下浸出30 min,铁、钪浸出率分别为11.32%、58.41%。酸浸铁、钪的动力学研究结果表明,赤泥酸浸铁的过程符合未反应收缩核模型,受化学反应控制,其表观活化能为41.79 kJ/mol;而赤泥酸浸钪的过程符合多相液固区域反应动力学特征,受扩散控制,其表观活化能为6.72 kJ/mol。     

拜耳法赤泥中铝铁的盐酸浸出过程研究

分析了拜耳法赤泥的矿物组成,通过热力学计算讨论了赤泥与盐酸反应可行性。通过正交试验得出了盐酸浸出赤泥的最佳条件。结果表明:对铝、铁浸出率显著性影响顺序分别为盐酸浓度温度液固比反应时间,盐酸浓度液固比温度反应时间;最佳条件为:盐酸浓度6 mol/L,温度110℃,液固比6:1,反应时间90 min;在最佳条件下,铝铁浸出率分别为83%和84%。浸出反应符合未反应收缩核模型的化学反应控制过程,铝、铁的浸出活化能分别为45.17 KJ/mol,22.35 KJ/mol。     

从广西某赤泥中盐酸浸出钪实验研究

对广西某赤泥经铝钠回收(亚熔盐法)-还原焙烧-磁选回收铁后得到的含钪物料进行了物相组成和盐酸浸出钪试验研究。物相组成研究结果表明,物料中主要矿物为Ca₂SiO₄和Ca₃Al₂O₆,是主要的耗酸矿物。盐酸浸出实验研究了浸出时间、温度、盐酸浓度和矿浆浓度对钪浸出率的影响,得到最佳工艺条件为:浸出时间4 h、浸出温度80℃、盐酸浓度6 mol/L和矿浆浓度7.7%,在最佳工艺条件下进行了3组综合试验,可获得钪平均浸出率73.27%。     

赤泥的弱酸浸出脱碱及综合利用研究

强碱性是制约赤泥综合利用的关键因素,酸浸是实现赤泥脱碱的有效方法。大部分研究采用强酸浸出赤泥实现重金属的回收,忽略了低浓度酸对赤泥脱碱化的影响。本文研究了低浓度的硫酸浸出赤泥过程中钠的浸出行为,同时考察了硫酸浓度、液固比、搅拌速度、浸出温度和浸出时间对赤泥脱碱化的影响。结果表明:采用pH 1的酸性溶液可以浸出赤泥中17.84%的钠。采用H+浓度为0.5 mol/L的酸性溶液可以浸出赤泥中大于60%的钠,这使得浸出液处理工艺相对简单,同时滤渣的pH值为8.5,为弱碱性,可直接用于土壤。在H+浓度为1.6 mol/L、固液比为1/4 g/mL、搅拌速度为300 r/min、浸出温度为298 K和浸出时间为10 min的最佳条件下,钠的浸出率为94.70%,滤渣中只剩下0.6% 的钠,可以用于建筑材料。并对硫酸浸出动力学进行了研究。结果表明:在较低浓度的硫酸介质中,钠的浸出过程主要受产物层扩散模型控制,浸出过程的表观活化能为16.99 kJ/mol。XRD分析结果证实方解石与硫酸反应生成硫酸钙微溶物质是形成产物层的主要原因。基于上述结果,提出了一种新型多级酸浸脱碱工艺,为赤泥的综合利用奠定了基础。      

硫酸浸出赤泥中铁、铝、钛的工艺研究

采用硫酸作为浸出剂, 研究了赤泥中3种金属铁、铝和钛的浸出工艺。通过考察反应温度、反应时间、液固比、硫酸浓度、赤泥颗粒粒径、焙烧温度、焙烧时间对浸出率的影响, 确定了3种金属离子的最佳浸出工艺条件。实验结果表明, 将粒径为0.15～0.18 mm的赤泥颗粒于600 ℃下焙烧5 h后, 在温度为60 ℃, 硫酸浓度为12 mol/L, 液固比为5的条件下反应1 h, Fe、Al、Ti的浸出率分别为46.7%、63.3%和54.3%。此外, 实验还采用扩散控制的收缩未反应芯模型对浸出反应的动力学进行了研究, 通过对实验数据的模拟分析, 得到了3种金属的浸出动力学方程。     

工业废盐酸浸出拜耳赤泥中铁、铝的试验研究

研究了工业副产废盐酸常压浸出拜耳法赤泥中铝、铁的过程。考察了盐酸浓度、浸出温度、浸出时间和液固比对氧化铁、氧化铝浸出率的影响。通过试验得出了较佳浸出工艺条件:盐酸浓度25%、酸浸温度90℃、酸浸时间60 min、液固比6∶1。在此条件下,铁的浸出率为92.51%,铝的浸出率为90.12%。各因素对氧化铝氧化铁浸出率影响大小为:酸浸反应温度盐酸浓度反应时间液固比。同时,利用硫酸铁作为除钙剂对赤泥盐酸浸出液进行脱钙处理,Ca~(2+)一次脱除率达83.3%。研究成果为低浓度工业废盐酸和贵州拜耳赤泥的处置与利用提供了理论依据和技术参考。     

微波加热强化赤泥浸铁的研究

以赤泥和硫酸为原料,采用微波加热法对赤泥中的铁进行浸出,分析各因素对铁浸出率的影响,研究微波对铁浸出的强化效果。微波加热下最佳浸出条件为:液固比11∶1 m L/g、温度90℃、硫酸浓度2.5 mol/L、赤泥颗粒粒径0.15～0.30 mm、搅拌速度200 r/min、浸出时间45 min。在最佳浸出条件下,铁的最大浸出率为93%。对浸出过程进行动力学分析中,采用缩核模型得到微波加热浸出过程的活化能(Ea=36.47 kJ/mol)和传统水浴加热浸出过程的活化能(Ea=42.35 kJ/mol),微波加热能显著降低浸出过程的活化能,对铁浸出具有强化作用。与传统水浴浸出对比表明,微波加热可以在一定程度上减少酸的消耗,缩短浸出时间,提高铁的浸出效率。     

钒钛铁精矿钛白废酸浸出提钒实验

为了提高钒钛铁精矿中V₂O₅的综合利用率,采用正交实验法,对其进行了钛白废酸直接浸出和焙烧-浸出实验。直接浸出实验结果表明,对V₂O₅浸出率影响最大的因素是液固比,影响最小的是废酸浓度;在浸出温度为90℃,浸出时间90 min,液固比为5和废酸浓度为20%时,钒钛铁精矿中V₂O₅的浸出率较高,其值为71.05%。焙烧-浸出实验结果表明,对钒浸出率影响程度由大到小分别是焙烧温度、碳酸钾配比、碳酸钠配比和焙烧时间;在焙烧温度为1000℃,焙烧时间1 h,碳酸钠配比为5%和碳酸钾配比为10%时,V₂O₅的浸出率可达84.48%。      

某低品位氧化镍矿酸浸正交试验研究

利用L16(45)正交试验对低品位氧化镍矿酸浸过程中酸的浓度,液固比,浸出时间,浸出温度和搅拌速率等影响镍浸出率的较大因子进行了研究。通过极差分析和方差分析对试验结果进行了分析,结果表明,影响镍浸出率的因素显著性依次为液固比>浸出温度>硫酸浓度>浸出时间>搅拌速率。镍的浸出优化条件为液固比为4:1,浸出温度为100℃,硫酸浓度为5.2mol/L,浸出时间2.5h,搅拌速率为250r/min,在此条件下镍的浸出率可达98.23%。研究可为优化类似镍矿酸浸工艺提供参考。     

赤泥中钛硫酸浸出的工艺条件及动力学研究

对用硫酸浸出赤泥中的钛的工艺条件及其动力学进行了研究。结果表明,在赤泥平均粒度约为74μm、硫酸浓度为6 mol/L、浸出温度80~95℃、浸出时间为3 h、搅拌速度为100 r/min的条件下,钛的浸出率在80%以上。动力学分析表明,赤泥的硫酸浸出是一级反应,浸出反应控制步骤是固膜扩散控制。     

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。