某难处理金矿生物预氧化研究

某金矿黄铁矿含量5.31%、氧化率6.02%,直接氰化金浸出率仅27.78%,属典型的低品位硫化物包裹型难处理金矿。为评估生物堆浸预氧化工艺对该矿石的工业化应用前景,开展了直接氰化浸出试验、生物搅拌预氧化试验和生物柱浸试验,考察了黄铁矿氧化率和金浸出率的关系以及温度对黄铁矿氧化率和金浸出率的影响。生物柱浸试验获得良好指标：原生矿破碎至P₈₀=5.5mm,在室温条件下(8-30℃)预氧化221天后,黄铁矿氧化率62.7%,金的浸出率为52.3%,氰化渣金品位为0.47g/t,较直接氰化浸出(金浸出率27.78%)金浸出率提高34.92个百分点。     

金精矿/软锰矿联合浸出提取金、锰工艺研究

以湖南黄金洞高砷高硫金精矿为原料, 开展了金精矿/软锰矿联合浸出提取金、锰新工艺研究。两矿氧化还原浸出, 可同时实现软锰矿还原浸出与黄铁矿、毒砂氧化分解。两段氧化还原浸出条件为: 两矿比5.4∶1, 酸矿比0.98∶1, 温度90 ℃, Ⅰ、Ⅱ段浸出时间分别为4 h和24 h, 在此条件下锰浸出率大于95%, 黄铁矿、毒砂分解率达到了99%; 氧化还原浸出渣金氰化浸出率随黄铁矿、毒砂氧化分解率提高而提高, 但在硫化矿几乎完全氧化分解情况下, 仅为70.56%, 有待进一步查明原因, 从而优化氰化浸出工艺条件。     

预浸出对硫化铜精矿硫酸化焙烧处理的影响

采用硫酸化焙烧-浸出-电积工艺来处理硫化铜精矿时增加预浸出可以使得铜浸出率增加,焙砂浸出液中影响铜电积的主要杂质元素Fe、Mn、Co等含量降低,预浸出段酸矿比0.3:1、温度50 ℃、时间3 h、液固比1:1时,Cu的最终浸出率大于99%,焙砂浸出液中Fe、Mn含量分别为0.12g/L和0.005g/L。通过预浸出段正交试验,确定了酸矿比对各个元素的浸出率影响最大,当酸矿比0.6:1,温度70 ℃,时间2 h,液固比1:1时,Fe的渣计浸出率为93.61%,Mn的渣计浸出率为59.50%,Mg的渣计浸出率为32.97%。     

高钙型低品位铜矿酸性浸出动力学研究

通过单因素实验及动力学分析研究了低品位氧化铜矿的浸出过程,考察了矿物粒度、浸出温度、硫酸浓度和液固比对浸出过程的影响。结果表明,适宜的浸出条件为: 矿物粒度-0.074 mm粒级占比85%、浸出温度60 ℃、浸出时间120 min、硫酸浓度2.5 mol/L、液固比4∶1,此时铜浸出率为96.23%; CaCO₃的存在导致浸出过程硫酸消耗增加; 浸出过程可用未反应核收缩模型来描述,反应速率受固膜界面传质和扩散混合控制,浸出过程活化能为8.78 J/mol。     

磁处理提高广东某含铜金矿金浸出率的试验研究

广东某含铜浮选金精矿的金品位为8.312 g/t、铜含量为5.18%,工业上采用全泥氰化、浸出渣浮选回收铜的工艺流程。矿石中较高的铜含量不仅消耗大量的氰化物,还影响了金的浸出效果。为了进一步提高金的浸出率、降低氰化物用量,采用加温常压化学预氧化浸铜—浸铜渣氰化浸金工艺回收试样中的铜和金,并在磁处理条件下,考察了磁场强度、磁化时间、起始硫酸浓度、NaCl浓度、浸出温度和浸出时间等因素对金、铜浸出率的影响。试验确定磁处理的最佳条件为：磁场强度150 kA/m,磁化时间50 min,磨矿细度-200目占88%,预氧化温度93 ℃,起始硫酸浓度0.77 mol/L,NaCl浓度0.76 mol/L,预氧化时间27 h。在此条件下进行氧化预处理浸铜及铜渣氰化浸金试验,固定搅拌强度为760 r/min,液固比为3∶1,氧气流量为160 mL/min,氰化钠用量为7 kg/t,铜和金的浸出率分别为85.76%、98.86%。较未进行磁处理的最佳指标（铜浸出率71.28%,金浸出率86.26%）相比,铜浸出率提高了14.48个百分点,金浸出率提高了12.60个百分点;此外,预氧化温度降低了2 ℃,预氧化时间减少了1 h,氰化钠用量减少了3 kg/t。研究结果表明磁处理能有效提高含铜金矿的铜、金浸出率,减少有毒氰化物的用量。     

含金银褐铁矿直接碱性浸出预分离锰银

云南某矿中的银多数以类质同象或微细粒包裹体存在于褐铁矿和铅硬锰矿中,直接采用氰化浸出其浸出率仅为30.26%。为提高银的氰化浸出率,采用直接碱性浸出法对矿物进行锰、银预分离实验,研究了不同反应条件对浸出的影响,以确立最优的工艺流程。结果表明,在浸出液中铵根的浓度为1.5 mol?L^-1、浓氨水为1.5 mL（在浸出液中的浓度为0.0195 mol?L^-1）、还原剂铜丝4 g、液固比为3:1的条件下,常温下反应4 h后,锰的浸出率为47.2%,而银不被浸出,实现了银和锰预分离。经碱浸后的渣再进行氰化浸出,银的氰化浸出率可提升至71.66%。该方法原材料价廉易得、操作简单、环境污染小,可在短时间内较好地实现锰和银的分离回收,具有较高的综合经济价值。     

酸性条件下高锰酸钾预处理氰化尾渣的试验研究

在酸性条件下采用高锰酸钾对氰化尾渣进行预处理, 分解载金黄铁矿。试验主要考察了反应时间和温度、矿浆浓度、高锰酸钾用量、硫酸初始浓度等因素对预处理效果的影响, 并确定了最佳反应条件。实验表明, 在固液比1∶20, 高锰酸钾用量75 g/L,反应时间5 h, 反应温度80 ℃, 硫酸初始浓度1.3 mol/L, 对应的铁浸出率及矿样失重率分别为92.82%和47.94%, 预处理效果较好。     

含铁氰化渣中铁的浸出性能和热力学研究

以含铁氰化渣为原料进行了酸浸试验, 考察了浸出酸用量系数、浸出温度和浸出时间对铁浸出率的影响。热力学分析结果表明, 氰化渣中的铁氧化物在高温、浓酸条件下以可溶性铁离子形式进入浸出液。试验结果表明: 在硫酸浓度45%、硫酸用量系数(硫酸理论用量的倍数)1.5、盐酸用量0.1 mL/g、体系沸点温度下、液固比3∶1、浸出时间4 h的最佳条件下, 铁浸出率为96.53%; 然后采用胶体分散法制备聚合硫酸铁回收浸出液中的铁。浸出渣氰化浸出试验结果表明, 金浸出率达到98.82%, 为实现氰化渣的综合利用提供了一种新的处理工艺。     

铜冶炼渣硫酸浸出回收铜试验研究

以硫酸溶液为浸出剂,采用常压氧化浸出法处理铜冶炼渣以回收渣中有价金属铜。考察了浸出温度,浸出时间,硫酸浓度,浸出液固比,氧化剂(双氧水)添加量对铜浸出率的影响。试验结果表明:在未加入氧化剂时,主要发生的是铜氧化物的简单酸溶反应,硫化铜几乎不溶于浸出液,因此铜浸出率很低;而随着氧化剂添加量的增加硫化铜被氧化浸出,因此铜浸出率增加很明显。此外,铜浸出率随着浸出温度,浸出时间和浸出液固比的增大而增大。浸出过程最佳的条件为:浸出温度70℃,时间180 min,硫酸浓度2 mol/L,液固比8∶1,氧化剂(双氧水)添加量400 m L/kg。铜浸出率可达到91.2%。通过对浸出渣XRD和SEM-EDS分析可得浸出渣中主要的矿物为磁铁矿。在磁场为2T的条件下,浸出渣磁选可以得到品位53.15%的铁精矿。     

含砷锑金精矿的生物预氧化-氰化浸金研究

采用嗜酸性氧化亚铁硫杆菌对含砷锑金精矿的生物预氧化-氰化浸金进行了研究。预氧化结果表明最佳生物氧化工艺参数为: 初始pH值范围为1.8～2.0, 矿石粒径-0.074 mm, 氧化温度为25～30 ℃, 摇床转速为140 r/min, 细菌接种量为20%, 液固比100∶2, 矿浆浓度1%～2%, 氧化时间12 d。浸出结果表明, 含砷、锑分别为10.37%和36.81%的金精矿如不经生物预氧化处理, 金浸出率仅41%左右;而经过12 d的生物氧化预处理, 金浸出率可达76.55%左右, 提高了35.62个百分点。生物预氧化可以脱除金精矿中的砷, 金的浸出率与砷的氧化率成正相关关系。研究结果能为生物预氧化含砷难处理金矿氰化浸金提供理论和技术指导。     

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