含砷铜渣N_2-CO气氛中还原焙烧脱砷新工艺

在分析含砷铜渣理化性质的基础上,研究了铜渣中砷在N2-CO弱还原焙烧过程中的挥发行为,系统考察了还原温度、还原时间和CO浓度等因素对脱砷效果的影响。结果表明,在氮气中通入一定的CO气体可实现砷酸盐的还原,并抑制铁橄榄石和磁铁矿的还原。在还原温度1 100℃、焙烧时间60 min、CO浓度2.5%、铜渣粒度75~100μm的条件下预处理后,铜渣中砷含量仅为0.044%,脱除率可达到70.17%,脱砷效果明显,为后续直接还原提铁实验提供了良好的原料条件。     

砷铁渣中砷和铁的资源化利用研究

采用磁化还原法回收砷铁渣中的砷和铁，优化实验条件为：焙烧温度650℃、碳加入量25%、焙烧时间180 min、氩气保护，此条件下砷挥发率达97.25%,焙烧渣中砷含量降至0.61%;砷以As₂O₃形式回收，纯度为99.13%;砷铁渣中铁被磁化，可采用磁选法以Fe₃O₄形式回收。该工艺实现了砷铁渣资源化利用。     

含砷铜渣预脱砷过程的热力学分析

采用HSC Chemistry 6.0 热力学分析软件研究了惰性气氛下焙烧温度对含砷贫化铜渣在预脱砷过程中砷平衡组成的影响, 并通过实验进行了验证。结果表明：在惰性气氛下, 升高温度可促进硫化砷的分解, 而砷酸盐的稳定性较好, 不能通过高温分解脱除。在温度低于500 ℃时, 固态硫化砷物相和氧化物不发生分解; 温度超过500 ℃后, As₂S₃、As₄S₄率先发生气化反应; 温度超过900 ℃后, 硫化砷开始发生分解。对于惰性气氛下铜渣的预脱砷, 实验结果与热力学分析吻合较好。     

高砷锌烟灰脱砷研究

以高砷锌烟灰为原料,采用低温硫酸化焙烧工艺,使烟灰中的砷以As_2O_3形式挥发逸出,经收尘系统收集。锌、铟、锗等有价金属在焙烧过程中转变为硫酸盐,实现了与砷的分离。考察了硫酸用量、温度、焙烧时间对脱砷的影响。结果表明,硫酸用量1.2倍理论量,温度300℃,焙烧时间3 h,焙烧过程砷的脱除率达78.28%。焙砂浸出时进入溶液中的少量砷与溶液中同时被浸出的少量铁一起通过氧化水解形成砷铁渣沉淀。砷铁渣与原矿混合后再经硫酸化焙烧,砷的脱除率达70.39%。     

含砷、锡铁精矿煤基直接还原焙烧脱除砷锡试验研究

采用煤基直接还原焙烧工艺对内蒙古黄岗含砷、锡铁精矿进行了焙烧脱除砷锡试验研究。考察了焙烧工艺、焙烧气氛及氯化剂用量等工艺参数对产品中砷、锡脱除效果的影响。结果表明, 砷主要是在中性焙烧阶段被氧化脱除, 锡是在还原焙烧阶段与氯化剂反应生成易挥发的氯化物挥发脱除。综合试验结果表明, 在优化条件下, 还原焙烧-磁选得到直接还原铁产品中TFe品位及回收率均达到88%, As残余含量0.03%, Sn残余含量0.07%。     

高砷锑烟尘焙烧脱砷试验研究

高砷烟尘是铜、铅等冶金过程中产生的一种难处理副产物,回收其中有价金属之前,需要先脱砷。采用焙烧方法对高砷锑烟尘进行了脱砷预处理,考察了焙烧温度和焙烧时间对脱砷率的影响。结果表明:在焙烧温度550℃,焙烧时间120 min的条件下,采用流动空气,As、Pb的脱除率分别为41.51%和59.81%,需要进一步控制氧势以提高脱砷率。     

铜冶炼白烟尘酸化焙烧工艺研究

针对云锡铜业高砷高锡低铜白烟尘,开展酸化焙烧选择性脱砷的研究,考察活性炭配比、浓硫酸配比、焙烧温度、焙烧时间对砷、锡、铅、锌、铋、铜挥发率的影响。在焙烧温度450 ℃、焙烧时间3 h、活性炭加入量5%、硫酸加入量30%较优条件下,白烟尘砷挥发率为94.28%,锡、铅、锌、铋、铜挥发率分别为2.34%、3.71%、2.96%、1.43%、1.64%。酸化焙烧实现了砷的选择性挥发,使白烟尘中的砷形成开路,为后续有价金属的分别回收创造了有利条件。     

基于Box-Behnken设计优化白银炉电收尘脱砷工艺

采用低温碱性焙烧-热水浸出工艺脱除白银炉电收尘(EPD)中的砷, 主要考察了焙烧过程中碱料比、焙烧温度、焙烧时间对砷浸出率的影响, 并利用响应曲面法的Box-Behnken设计优化工艺参数。结果表明, 3个因素对EPD中砷的浸出率均有影响, 其中焙烧温度对砷浸出率影响最大。结合单因素实验结果及Box-Behnken设计优化后焙烧条件为: 碱料比1.2, 焙烧温度600 ℃, 焙烧时间2 h。优化条件下, EPD中砷浸出率为90.76%, 铅、锌、铜、铋均不浸出。低温碱性焙烧-热水浸出工艺能实现EPD中砷的选择性脱除, 有价金属富集在浸出渣中得以综合回收。     

铜渣还原-熔分过程中砷的行为特征

对铜渣直接还原和高温熔分过程中砷的行为特性进行了研究。结果表明,直接还原过程中,砷脱除率较低,只有26.0%左右,升高温度、提高配碳量和炉料碱度均不利于砷的脱除,而延长还原时间可促进砷的脱除。在保证球团金属化率的基础上,在还原温度1 300 ℃、C/O比1.2、碱度0.6、还原时间30 min的最优条件下,还原后球团内砷含量最低为0.073%。高温熔分过程中,砷元素富集进入铁相,少部分进入渣相,在保温温度1 455 ℃、CaO添加量4%、CaF₂添加量1%、保温时间30 min时,铁相中砷含量为0.082%。     

铜冶炼渣固废资源制备珠铁的研究

为了最大程度地回收铜渣中的铁资源、得到高品质的珠铁产品, 在实验室条件下模拟转底炉, 使用高温炉焙烧还原由铜渣、还原煤、石灰石制备的含碳球团, 直接还原生成珠铁和渣, 再通过人工挑选的方式实现渣铁分离。研究了焙烧温度、焙烧时间、还原煤用量、石灰石用量等因素对焙烧效果、珠铁全铁品位、铁回收率的影响, 确定较佳的球团配料比为铜渣∶还原煤∶石灰石=100∶20∶10, 较佳的焙烧条件为焙烧温度1 400 ℃、焙烧时间40 min, 最终可获得铁回收率91.04%、全铁品位94.72%、C含量1.23%的高品质珠铁。     

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。