铜冶炼渣中铁的生物炭深度还原—磁选回收试验

铜冶炼渣中铁含量达30%~40%,但铁元素主要以铁橄榄石的形式存在,采用传统方法难以回收利用。以可再生生物炭为还原剂,通过深度还原—磁选回收铜冶炼渣中的铁,考察了还原条件对铜冶炼渣深度还原的影响。当还原温度为1 200 ℃、还原时间为75 min、CaO用量10%、碳氧摩尔比为1.5时,深度还原产品的金属化率达到86.83%,经过磨矿磁选可获得铁品位为62.84%、回收率为81.92%的磁选精矿。铜冶炼渣中主要含铁矿物有Fe2SiO4、Fe3O4及少量的Fe2O3,其还原过程为Fe2SiO4→FeO→Fe、Fe2O3→Fe3O4→FeO→Fe,得到的金属铁逐渐聚集长大最终形成有利于磁选分离的金属铁颗粒。     

红土镍矿电炉还原炼镍铁合金的研究进展

综述了我国红土镍矿电炉还原炼镍铁的研究进展,重点总结了炼镍铁的机理与研究现状,分析了该技术的难点及其发展趋势。结果表明:红土镍矿中各氧化物的还原先后顺序为NiO>NiFe2O4>Fe2O3>SiO2>MgO。SiO2/MgO在1.6～2.8,FeO含量在20%～30%时,渣与金属密度差异大,且具有良好的流动性,有利于渣与金属分离,提高镍的直收率。渣型对脱硫影响也较大,在碱性渣范围内适当提高炉渣碱度,有利于炉渣脱硫,但是碱度过大会导致渣黏度变大而对脱硫不利。采用电炉还原熔炼工艺生产镍铁具有流程短、镍铁品位易控、金属回收率高的优点,但对于强化冶炼过程、提高作业效率、进一步提高镍铁合金的金属镍含量等问题还有待在生产实践中继续摸索解决。     

低贫难选铁矿深度还原中助熔剂的研究现状及进展

针对低贫难选铁矿深度还原中助熔剂的研究,从助熔剂的种类及用量对深度还原的影响、机理研究等方面入手,论述了国内深度还原助熔剂的研究现状及进展,同时对助熔剂在深度还原中的动力学和热力学研究进行了阐述。研究认为,常用助熔剂有钙基和钠基助熔剂,在低贫难选铁矿深度还原中加入这两种助熔剂都会提高Fe2O3还原为Fe3O4的反应速率,同时减少或避免了2FeO·SiO2等比FeO更难还原的氧化物的生成,因此可以降低系统还原温度,且利于铁粒粒径的增大,但是这两种助熔剂的助熔效果不大相同,这与反应温度和被还原铁矿性质有关。     

降低铜密闭鼓风炉富氧熔炼四氧化三铁影响的生产实践

在铜密闭鼓风炉熔炼过程中,Fe3O4会从冰铜和炉渣中析出,沉积在炉底、炉侧壁及前床,严重影响生产。通过适当提高转炉渣中SiO2含量(21%～24%),可以减少进入鼓风炉(转炉渣作为块料)的Fe3O4量;选择并控制合理的熔炼渣型(Fe31%～35%、SiO233%～36%、CaO11%～13%,SiO2/Fe≈1 13,渣含Cu<0 30%)及精心操作,成功地避免了Fe3O4对鼓风炉生产的危害。     

铜吹炼渣侧吹贫化新工艺研究

提出把传统的P-S转炉改造为具有将燃料喷射进炉膛保温和固体还原剂从风口喷入熔池功能的还原转炉,创造弱还原气氛处理铜吹炼渣的新工艺。研究结果表明,该工艺能耗低,Fe3O4还原彻底,铜回收率高。处理50 t含Fe3O4为41%的吹炼渣,当控制炉温为1250℃、煤基还原剂输送速率为30 kg/min、渣中Fe/SiO2=1.25时,可将渣中的Fe3O4降至5%以下。工业验证性试验表明,用此工艺处理50 t含Fe3O4为46%的转炉渣,经过还原后弃渣含Cu 0.34%、含磁性氧化铁3.55%,铜的回收率为89.4%。     

加拿大派普斯通湖钛磁铁矿回收钛、钒和铁的方法

对于加拿大马尼托巴省派普斯通湖含钒的钛磁铁矿矿床，现已在实验室开发出一种火冶和水治相结合的方法，以回收钛、钒和铁。矿石含Fe57．5％、V0.66％和TiO216．6％．矿石经过选择还原熔炼，因此，大部分的铁存在于金属相中，而钒和钛则存在于渣相中．铁的纯度达到99％，渣中含FeO9％～35％、ToO231％～46％和V1．2％～1．6％．98％以上的钛和钒成为渣相。渣在950℃的条件下，用苏打发焙烧，然后用80℃的热水浸析以回收钒。浸析后的残余物在105℃的条件下再用盐酸加以处理，主要除去铁、镁和铝，以提高TiO2的含量。最终产品含TiO282．9％、FeO1.5％、SiO215．6％、MgO1％、Al2O32％和CaO0.3％；钛的总回收率为90％以上。这种产品可用作颜料工业的原料．     

轧制工艺对热轧船板表面耐海岸大气腐蚀行为的影响

利用恒温恒湿腐蚀模拟试验方法,辅以扫描电镜(SEM)、能谱(EDS)和X射线衍射(XRD)等材料分析手段,对不同轧制工艺下的船板表面进行耐海岸大气腐蚀研究,得到轧制工艺对船板表面耐海岸大气腐蚀行为的影响规律。结果表明,热轧船板表面的氧化铁皮以Fe3O4、Fe2O3和FeO为主,随终轧温度升高、终冷温度降低,Fe3O4含量明显增加,Fe2O3含量减少;在680～850℃内对钢板实施弱强度水冷,冷速为6～15℃/s,减少了450～600℃降温过程中表面氧化铁皮Fe3O4转化为Fe2O3的比例;氧化铁皮中Fe3O4的含量控制在40%～60%,Fe2O3的含量低于30%,FeO含量高于10%,降低了氯离子引起的点蚀蚀坑数量和深度,延长船板在海岸大气环境下的存储期。     

铅银渣混配铅精矿直接还原熔炼成渣特性及动力学解析

利用铅火法熔炼资源化消纳铅银渣等含铅固废已成为大势所趋。然而,由于原料结构明显差异导致常规高铅渣直接还原控制理论并不适用于混配铅银渣的反应过程。为此,本文在原料赋存状态及热力学分析基础上,结合还原实验对资源化消纳铅银渣的直接还原过程成渣特性及反应动力学规律进行了研究。结果表明,还原初期及还原后期( >30 min )均受界面反应控制,还原20~30min内受外扩散控制,可通过增大反应界面及降低黏度来强化还原反应效率。随还原过程进行,渣中含铅相不断减少,锌黄长石相和铁锌尖晶石不断增加,硅酸盐结构由简单SiO44-^变为Si2O74-^,还原渣熔化温度及黏度均有所增加;控制终渣FeO/SiO2=1.6,CaO/SiO2=0.6,ZnO≤20 wt.%,可满足还原熔炼生产要求。     

闪速炼铜过程中四氧化三铁的生成与控制

闪速炉炼铜炉渣中含Fe3 O4较高 ,这是渣含铜高和沉淀池结瘤的主要原因。本文结合生产实践 ,论述了Fe3 O4在闪速熔炼过程中的生成机理 ,并在生产中采取一系列措施 ,如 :通过下料管、分布器等设备改造改善精矿喷嘴性能 ,反应塔加焦粉 ,沉淀池加生铁 ,并适当提高炉渣SiO2 含量等 ,以减少Fe3 O4对生产过程的危害。     

闪速熔炼渣含铜的数值模拟

通过数值仿真的方法,分析闪速熔炼反应塔内Fe3O4含量的分布与变化规律,提出降低渣含铜的途径和措施.计算表明,精矿喷嘴操作参数的优化匹配,可以减少反应塔底部Fe3O4的生成量.氧浓或氧量分布为调控的主要参数;工艺风氧浓高,工艺风速低,有利于减少Fe3O4生成量;增加SiO2台量,颗粒中的Fe3O4含量明显降低,但需综合考虑此因素对渣含铜的影响.调整反应塔精矿喷嘴的工艺风氧量和氧浓,使反应塔内的氧势呈合理的梯度分布,将有助于渣含铜的降低.     

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