喷淋塔中固定化Acidithiobacillus ferrooxidans对Fe2 的生物氧化特性研究

为了增大嗜酸氧化亚铁硫杆菌细胞密度以提高其对Fe~(2+)的氧化速率,利用泰勒花环填料为载体,在喷淋塔中固定嗜酸氧化亚铁硫杆菌,考察固定化细胞对Fe~(2+)的生物氧化性能。采用扫描电子显微镜对载体表面进行形貌表征,X射线衍射仪和傅里叶红外光谱仪对填料表面沉淀进行成分分析。结果表明:在改良的9 K培养基中,嗜酸氧化亚铁硫杆菌被成功的固定在泰勒花环填料上,并伴有少量黄铵铁矾沉淀,这些沉淀和菌体细胞一起构成了生物反应系统的生物膜。嗜酸氧化亚铁硫杆菌在喷淋塔中完成固定化后,溶液初始pH值和温度是影响氧化速率的主要原因,其优化结果分别为2.25和34℃。在此条件下,整个生物反应系统能长期保持稳定的氧化特性,Fe~(2+)的氧化速率为4.27 g/L/h。     

氧化亚铁硫杆菌对低品位锰矿浸出的试验研究

以软性塑料纤维为填料而构建了氧化亚铁硫杆菌的固定化生物反应器,经低pH值和高浓度Fe2+长期驯化后,在初始pH=1.6、Fe2+浓度25 g/L、温度30℃、进气量0.45 m3/h、循环液体流量0.85 L/h的条件下,固定化细胞只需3 d,Fe2+氧化率可达82.27%,其Fe2+平均氧化速率为0.29 g/(L.h);固定化细胞达到80%以上的氧化率所需时间比游离细胞提前了4 d,其平均氧化速率是游离细胞的2.5倍。对低品位菱锰矿的浸出,在pH为1.7、温度60℃、Fe3+浓度20 g/L、矿浆浓度10%条件下,搅拌3.5 h可达将近85%的浸出率。     

生物法再生铁离子溶液对铁闪锌矿的浸出

以沸石为填料,采用吸附法构建了氧化亚铁硫杆菌的固定化生物反应器。运行结果表明,在初始pH=1.6、Fe2 浓度8.58 g/L、气体流量0.45 m3/h、液体流量0.3 L/h及温度为30℃的条件下,Fe2 氧化率可达94.76%,Fe2 平均氧化速率高达1.22 g/L/h;固定化细胞Fe2 的平均氧化速率是游离细胞的9.38倍。菌生Fe3 浸矿剂对铁闪锌矿的浸出表明,在初始pH=1.5、Fe3 浓度为8 g/L、温度为70℃的条件下浸出8 h,当矿浆浓度小于3%时,浸出率可达90%以上,其中矿浆浓度为1%时的浸出率高达95.18%。     

高铁离子浓度环境下氧化亚铁硫杆菌的生长行为

对氧化亚铁硫杆菌在高铁离子浓度下的生长情况进行了研究。在初始[Fe2+]=10、30、50、70、90g/L的高铁离子浓度9K培养基中培养氧化亚铁硫杆菌,定时测培养基中的细菌数、pH值及氧化还原电位(Eh)和Fe2+的终浓度,试验得出:[Fe2+]为30g/L时,氧化亚铁硫杆菌的生长最为旺盛,浓度达到9×107个/mL;在接种量为10%、pH值为1.6的情况下,氧化亚铁硫杆菌的Fe2+氧化速率最高,分别达到2.87g/(L.d)和2.67g/(L.d)。     

燃煤烟气微生物循环脱硫工艺研究

以氧化亚铁硫杆菌固定化生物膜和铁离子复合体系为基础构建了燃煤烟气的微生物循环脱硫工艺。以多面空心球为载体实现了氧化亚铁硫杆菌的固定化,固定化生物膜具有孔隙率高、比表面积大的特点,有利于细菌的吸附及SO₂的脱除。脱硫试验表明,SO₂入口浓度1 000 mg/m³以下,烟气流量1.0 m³/h,循环液流量40~60 L/h为适宜工艺条件。     

氧化亚铁硫杆菌的驯化与诱变选育

以高含量的硫化物金精矿为驯化介质 ,将驯化后的氧化亚铁硫杆菌 (T.f菌 )用紫外线、微波作为诱变剂进行选育 ,经过诱变选育的 T.f菌的氧化活性由未被驯化、诱变前的 0 .0 7g/L· h提高到 3.18g/L·h;氧化活性提高了 4 0多倍 ,有效地提高了氧化亚铁硫杆菌对硫化物的氧化分解能力 ,为优势浸矿菌种的选育提供了简便、有效的育种手段     

氧化亚铁硫杆菌在硫化矿物表面的吸附

研究了氧化亚铁硫杆菌在黄铁矿、黄铜矿、方铅矿和闪锌矿表面的吸附情况,结果表明,氧化亚铁硫杆菌在4种硫化矿物表面的吸附无明显选择性;溶液初始pH值对氧化亚铁硫杆菌在4种硫化矿物表面的吸附几乎无影响,但酸性环境有利于吸附的发生;细胞悬浮液浓度为0.1～1.0 g/L、矿浆浓度为15 g/L以上和温度为20～30 ℃是氧化亚铁硫杆菌在4种硫化矿物表面吸附的较适宜条件。扫描电子显微镜检测结果显示,氧化亚铁硫杆菌细胞表面的荚膜是重要的吸附位。红外光谱分析结果表明,氧化亚铁硫杆菌细胞表面含有-OH、-NH₂、C=O、C-O等活性基团,它们在吸附过程中起重要作用。     

耐冷嗜酸硫杆菌的生长特性和固定化培养

为解决氧化亚铁硫杆菌、嗜铁钩端螺旋菌等中温菌在低温和高酸的吸附尾液中作氧化剂时生长繁殖慢、氧化Fe²⁺速率低等问题,以耐冷嗜酸硫杆菌为研究对象,结合新疆某地浸采铀现场生产实际,对该菌的生长特性、耐酸驯化和固定化培养进行了探索。结果表明,该菌的接种量以10%为宜;当初始Fe²⁺浓度为0.3~0.5 g/L时,细菌仍能较快氧化Fe²⁺;在5~25℃条件下,耐冷嗜酸硫杆菌氧化Fe²⁺的速率均高于氧化亚铁硫杆菌,即耐冷嗜酸硫杆菌更适于溶浸液低温环境;耐冷嗜酸硫杆菌耐酸驯化后能在pH=0.31的培养液中保持较好的氧化活性;从生物陶粒表面电镜图片中可以观察出较厚的生物膜,固定化细菌和游离态细菌协同氧化Fe²⁺的速率是游离态细菌单独氧化的3.4倍。     

闪锌矿对氧化亚铁硫杆菌Fe2＋氧化活性的影响

研究闪锌矿对氧化亚铁硫杆菌Fe2 氧化活性的影响。结果表明，在30℃、pH2．0浸出条件下，9K介质中低矿浆浓度的闪锌矿精矿、原矿对氧化亚铁硫杆菌的Fe2 氧化活性有抑制作用，且随着矿浆浓度的增大而加剧。9K介质中石英矿浆浓度为0．25％和0．50％时，对细菌的Fe2 氧化速度无明显影响。而矿浆浓度达0．75％和1．0％时，则降低细菌的Fe2 氧化速度。     

氧化亚铁硫杆菌固定化技术及其应用

氧化亚铁硫杆菌是一种重要的浸矿细菌,细胞固定化技术能将该菌限定在特定的区域内,增加细菌密度,有效提高其对Fe2+及低价态硫的氧化能力,且能提高细菌的稳定性和机械强度,并简化浸矿生产条件,最终提高工业生产的经济效益。该技术运用的材料包括有机材料、无机材料和人工合成材料;涉及到的固定化方法包括吸附法、包埋法、交联法、新固定化法等。固定化氧化亚铁硫杆菌技术在生物浸矿和生物脱硫领域具有良好的应用前景,该技术的发展为其实现产业化奠定了基础。     

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