大洋多金属结核与低品位硫化镍矿耦合浸出特性

基于低品位硫化镍矿的还原活性和大洋多金属结核的氧化活性,提出复杂低品位多金属矿的耦合酸浸处理工艺。主要考察Mn与S矿石质量比、硫酸浓度、温度对主金属元素浸出的影响,并采用XRD和SEM-EDS及电化学极化、循环伏安等分析耦合酸浸处理过程中主金属元素的浸出特性。研究结果表明:在最佳条件即Mn与S矿石质量比为0.55、初始硫酸浓度为1.3 mol/L、温度为355 K时,Ni,Mn,Cu,Co和Fe的浸出率分别为96.8%,97.3%,92.2%,97.9%和28.9%;金属硫化物还原MnO_2而溶出结核中Ni,Cu和Co,同时自身被氧化腐蚀成S0,SO_4~(2-)和金属离子而溶解;将Fe以铁矾或氧化矿物形式沉淀在渣相中,选择性浸出Ni,Mn,Cu和Co可行;耦合酸浸工艺利用矿石的氧化还原活性,实现了不同类型的复杂低品位矿石中有价金属的高效提取。     

硫酸铵-溴化四丁基铵水体系液液萃取分离铅

研究了硫酸铵-溴化四丁基铵(TBAB)-水体系萃取分离铅的行为及其与常见离子的分离条件.试验表明,TBAB的水溶液在硫酸铵的作用下盐析,形成了液-液两相,在pH3～5的克拉克-鲁布斯缓冲溶液中,Pb2+与Br-形成的络阴离子PbBr42-能与溴化四丁基铵TBA+形成疏水性的三元离子缔合物(TBA+)2(PbBr42-)而被萃取到上层TBAB相,其他共存离子:Zn2+,Cu2+,Ni2+,Co2+,Mn2+,Fe3+不被萃取.控制溶液的酸度,该体系能够使Pb2+与常见金属离子Zn2+,Cu2+,Co2+,Ni2+,Mn2+,Fe3+等完全分离.对合成水样进行了萃取分离测定,结果满意.     

Heusler合金Mn2V0.5Co0.5Al的晶体结构与磁性能研究

本文在三元Heusler合金Mn2VAl的基础上掺杂Co原子得到四元合金Mn2V0.5Co0.5Al,基于密度泛函理论(DFT)的第一性原理赝势方法结合广义梯度近似(GGA),对四元Heusler合金Mn2V0.5Co0.5Al的电子结构、磁性及半金属特性进行计算.结果表明,Co原子掺入能抑制Mn2V0.5Co0.5A...     

蛇纹石中和渣制备氧化铁红和回收镍的工艺研究

采用硫酸浸出蛇纹石中和渣,并用红透山硫铁矿还原酸浸液;然后用NaOH沉淀去除Al和Cr,用Na₂S沉淀回收Ni、Co、Mn;再经碳酸氢铵沉淀铁,焙烧制备氧化铁红。采用X射线衍射仪(XRD)、扫描电镜(SEM)和X射线荧光光谱分析(XRF)等对硫铁矿还原过程进行研究。研究结果表明：在反应温度85℃、反应时间260 min条件下,酸浸液中Fe³⁺完全被硫铁矿还原,pH从0.94提高到2.90;还原后硫铁矿由片状团聚体转变为球形团聚体,硫产物由27.81%S、33.96%H₂SO₄和38.22%H₂S(质量分数)组成,硫铁矿表面没有单质硫覆盖。用NaOH中和沉淀可完全去除Al和Cr。Na₂S沉淀回收93.01%镍、91.62%钴,得到镍含量为13.47%(质量分数)的Ni、Co和Mn沉淀渣,达到镍精矿YS/T 340—2014中1级品标准。将纯化后的硫酸亚铁溶液沉淀,在600℃焙烧得到氧化铁红,颜色与三环颜料公司的H101产品相似,着色力达125.45%,质量符...     

Mo-Ni/γ-Al2O3甲烷化催化剂研究(Ⅱ)制备条件及还原条件对催化剂结构的影响

用程序升温还原 ( TPR)、程序升温脱附 ( TPD)、X射线粉末衍射 ( XRD)及透射电子显微镜 ( TEM)等法对分步浸渍法制备的一系列 Mo-Ni/ γ-Al2 O3甲烷化催化剂的结构进行了表征 .考察了浸渍液的 p H值、焙烧温度及还原温度对催化剂的表面结构的影响 .结果表明∶先浸 Mo时 ,调 ( NH4 ) 6Mo7O2 4 溶液的 p H=3、浸 Mo后 50 0℃焙烧的催化剂易于还原 ,而且能抑制后浸 Ni时 ,难还原铝酸盐的形成 ;浸 Ni时 ,调 Ni( NO3) 2 溶液的 p H=8,浸后 4 30℃焙烧的催化剂易于还原 ;浸 Mo后 ,650℃焙烧易形成难还原的 Al2 ( Mo O4 ) 3,浸 Ni后 530℃焙烧的催化剂易形成难还原的 Ni Al2 O4 与类 Ni Al2 O4 铝酸盐 .催化剂于 50 0℃还原时 ,还原态的 Ni最多 ,4 50℃还原时有利于 Mo-Ni合金的形成     

长循环单晶镍钴锰三元正极材料的制备和表征

采用固相法制备出镍钴锰三元氧化物Li Ni0.5Co0.2Mn0.3O2的单晶材料,然后,进行镁、钛掺杂处理。采用XRD,SEM和恒流充放电等测试手段对材料的晶体结构、形貌和电化学性能等进行研究。测试结果表明,材料形成形貌良好的单晶颗粒,且经过镁、钛掺杂处理后的材料单晶形貌没有改变。掺杂镁、钛后,材料的电化学性能得到明显的改善,Li Ni0.5Co0.2Mn0.3O2的单晶材料掺杂镁、钛后容量从159.59 m Ah/g提升到162.57 m Ah/g,做成全电池后,2 C的放电效率从79.6%提高到了87.3%,1 C下循环300圈后的容量保持率从84.89%提高到92.9%。     

Ni、Co、Mn（Salen）／MCM-41的制备及其催化性能的研究

直接合成法制备了NH2-MCM-41,进而负载Ni、Co、Mn（Salen）配合物制备了催化剂．采用傅里叶变换红外光谱（FT-IR）、X射线衍射（XRD）对催化剂进行了表征．将这些催化剂用于以H2O2为氧化剂的环己烯环氧化反应,结果表明：与Ni（Salen）／MCM-41和Co（Salen）／MCM41相比,Mn（Salen）／MCM41具有较高的反应活性．以Mn（Salen）／MCM41为催化剂,获得了优化的反应条件：在n（C6H10）／n（H2O2）=3、20mL乙腈为溶剂、反应时间4h的条件下,环己烯转化率为8．0％,选择性为47．5％．     

不同锂源对富锂锰基Li1.133Mn0.466Ni0.2Co0.2O2正极材料性能的影响研究

采用共沉淀的方法将含有一定比例的镍、钴、锰的金属醋酸盐溶液均匀混合,然后加入适当的沉淀剂Na2CO3制备前驱体Mn0.466Ni0.2Co0.2CO3,最后分别与不同锂源（Li2CO3、LiOH）混合煅烧得到富锂锰基Li1.133Mn0.466Ni0.2Co0.2O2正极材料。采用XRD和SEM分别对不同锂源制备的Li1.133Mn0.466Ni0.2Co0.2O2的结构和表面形貌进行表征,采用恒电流充放电和循环伏安法测试对不同锂源制备的Li1.133Mn0.466Ni0.2Co0.2O2的电化学性能进行测试。结果表明,以LiOH为锂源合成的样品在0.1C倍率下首次充、放电比容量分别为330.1mAh/g和218.6mAh/g,首次库仑效率为66.23%,在1C倍率内表现为优秀的稳定循环比容量特性,但是在2C以及2C以上高倍率循环稳定性不及以Li2CO3为锂源合成的样品性能。     

稀土系贮氢三元合金的生成焓计算

利用 Miedema理论和几何模型计算了合金 La- M,Ni- M( M=La,Ni,Co,Mn,Al,Cr,Fe,Cu,Ga)和稀土系贮氢三元合金系统 La Ni5- x Mnx( M=Co,Mn,Al,Cr,Fe,Cu,Ga)的生成焓 ,计算结果与已有实验结果符合得较好 .结果表明 ,添加合金组元 Mn,Co,Cr,Fe和 Cu,三元合金 La Ni5- x Mx 的生成焓有不同程度的增大 ,而添加Al,Ga生成焓则明显减小 .讨论了生成焓对高温氢化时合金发生歧化反应的影响 ,合金的生成焓愈大 ,对歧化反应愈有利 .计算得到的生成焓数据与实验获得的合金歧化反应趋势和程度相符合     

用1-(2-吡啶偶氮)-2-萘酚改性硅胶富集和分离痕量金属离子(英文)

将1-(2-吡啶偶氮)-2-萘酚(PAN)吸附在硅胶(SG)上,制备得到改性硅胶PAN-SG。PAN-SG对Cu(Ⅱ)、Co(Ⅱ)、Ni(Ⅱ)的最大吸附量分别为3.1,1.8,1.8μmol/g。用PAN-SG色层柱可以富集Cu(Ⅱ)、Co(Ⅱ)、Ni(Ⅱ)等金属离子,富集倍数超过200,金属离子的回收率大于95％;Cu(Ⅱ)与Cd(Ⅱ)、Mn(Ⅱ)可以在PAN-SG柱上直接分离;选择合适的洗脱液,可使性质相近的Cu(Ⅱ)、Co(Ⅱ)得到分离。用PAN-SG柱富集人工水样和天然水样,用PAN分光光度法测定Cu(Ⅱ)的下限可达ppb级。     

废旧锂电池正极活性材料硫酸浸出液萃取纯化

研究了酸性膦类萃取剂P204,P507与协萃剂Lix54,Lix84配方对废旧锂电池正极材料的硫酸浸出液萃取除Al的反应规律.研究表明:P507+Lix84复合体系萃取分离Al/Mn的效果最佳.以最优配方5% P507+5% Lix84/煤油,在pH 为 4.0,水油体积相比V_○a/V_○o为1∶1时,Al,Cu,Co,Ni,Mn和Li的单级萃取率分别为89.1%,80.8%,3.4%,2.6%,3.2%和0.3%.在V_○a/V_○o为1∶4时,经两级(理论级)萃取,母液中Al 的质量浓度为0.88g·L^-1,萃取率大于97.7%;负载油相用2.0mol/L硫酸溶液反萃,在V_○a/V_○o为10∶1时,经两级(理论级)反萃,有机相中Al的质量浓度为0.79g·L^-1,反萃率大于99.0%.     

采用焙烧-水浸法从报废锂离子动力电池中回收金属

锂离子动力电池在新能源汽车中已获得广泛应用,其报废后Li、Ni、Co、Mn等金属清洁高效回收对促进有色金属循环利用具有重要意义.从LiNi_0.5Co_0.2Mn_0.3O₂为正极材料的锂离子动力电池中回收Li、Ni、Co、Mn,并采用TG-DSC、XRD、ICP-OES、XPS、热力学分析等研究了回收过程物相演变规律及影响金属回收率的主要因素.结果表明:由LiNi_0.5Co_0.2Mn_0.3O₂与NaHSO₄·H₂O组成的混合物,经过焙烧后Li、Ni、Co、Mn元素的赋存状态发生改变,从不溶于水的复杂金属氧化物形式,转化为可溶于水的金属硫酸盐形式.焙烧产物在一定条件下用水浸出后,Li、Ni、Co、Mn元素以金属离子的形式转移到水溶液中获得回收.混合物的组成、焙烧温度对Li、Ni、Co、Mn元素在焙烧产物中的赋存形式呈现制约关系,也是影响Li、Ni、Co、Mn金属回收率的主要因素.     

正极材料Li(Ni1/3Co1/3Mn1/3)1-xCrxO2的合成与表征

采用草酸盐共沉淀法合成一系列的Li(Ni_1/3Co_1/3Mn_1/3)_1-xCr_xO₂正极材料(0 ≤x ≤0.1),用X射线衍射仪（XRD）和扫描电子显微镜（SEM）分析合成产物的晶体结构及表面形貌;利用充放电仪测定了产物的电化学性能.结果表明,合成的Li(Ni_1/3Co_1/3Mn_1/3)_1-xCr_xO₂( x = 0.01,0.03,0.05,0.07) 均保持α-2NaFeO₂ 层状结构相,属于空间R3m点群.Li(Ni_1/3Co_1/3Mn_1/3)_0.95Cr_0.05O₂的电化学性能最佳,首次放电容量达158.6 mAh/g,在2.5～4.5 V区间30次循环后比容量衰竭率仅为3.92%.Li(Ni_1/3Co_1/3Mn_1/3)_0.95Cr_0.05O₂和Li(Ni_1/3Co_1/3Mn_1/3)CrO₂ 的电极阻抗变化不同,进而影响其电化学性能.     

LiCoO2的化学分解浸取过程

废旧锂离子电池中钴的含量较高．钴具有较强的毒性,且资源稀少．为此,研究了废旧锂离子电池的湿法回收工艺过程,并分析了废旧锂离子电池中钴和锂在硫酸溶液中的漫取过程动力学．采用了解体电池塑料外壳、钢壳、正负极材料、N-甲基吡咯烷酮(NMP)分离铝箔与正极活性材料以及硫酸浸取钴与锂的回收工艺．结果表明,铝片的回收率接近100％,钴和锂的浸取率均超过99．6％,同时分析了漫取过程中的工艺参数对钴和锂的漫取率的影响．     

直接回收锰酸锂制备超级电容器MnS材料的研究

本文通过将锂离子电池正极废料锰酸锂转化为超级电容器材料MnS的方法来进行锰酸锂废料的再生利用。将正极废料溶解浸出后,调整废料浓度并加入硫源,水热得到MnS材料。X射线衍射、扫描电镜、透射电镜以及比表面分析仪测试的结果显示,水热法制备的MnS呈现良好的晶体结构,并具有较好的电容器特性。探究不同Mn2+浓度对最终产物性能影响发现:浸出液中Mn2+的浓度对最终产物的形貌、比表面积均有影响。其中当Mn2+浓度为0.5 M时,可以得到三维花状辐射结构。该辐射结构有利于提升电解液与材料之间的表面接触,从而促进材料电容性能。该种思路为锂离子电池正极材料的回收提供了新的思路,值得进一步的深入探究。     

Recovery and regeneration of LiFePO4 from spent lithium-ion batteries via a novel pretreatment process

The recycling of spent LiFePO4 batteries has received extensive attention due to its environmental impact and economic benefit. In the pretreatment process of spent LiFePO4 batteries, the separation of active materials and current collectors determines the difficulty of the re-covery process and product quality. In this work, a facile and efficient pretreatment process is first proposed. After only freezing the electrode pieces and immersing them in boiling water, LiFePO4 materials were peeled from the Al foil. Then, after roasting under an inert atmosphere and sieving, all the cathode and anode active materials were easily and efficiently separated from the Al and Cu foils. The active materials were subjected to acid leaching, and the leaching solution was further used to prepare FePO4 and Li2CO3. Finally, the battery-grade FePO4 and Li2CO3 were used to re-synthesize LiFePO4/C via the carbon thermal reduction method. The discharge capacities of re-synthesized LiFePO4/C cathode were 144.2, 139.0, 133.2, 125.5, and 110.5 mA·h·g?1 at rates of 0.1, 0.5, 1, 2, and 5 C, which satisfies the requirement for middle-end LiFePO4 batteries. The whole process is environmental and has great potential for industrial-scale recycling of spent lithium-ion batteries.     

氯化亚锡作为还原剂在废旧锂离子电池有价金属浸出回收中的应用研究

The reductant is a critical factor in the hydrometallurgical recycling of valuable metals from spent lithium-ion batteries (LIBs). There is limited information regarding the use of SnCl₂ as a reductant with organic acid (maleic acid) for recovering valuable metals from spent LiCoO₂ material. In this study, the leaching efficiencies of Li and Co with 1 mol·L?1 of maleic acid and 0.3 mol·L?1 of SnCl₂ were found to be 98.67% and 97.5%, respectively, at 60°C and a reaction time of 40 min. We investigated the kinetics and thermodynamics of the leaching process in this study to better understand the mechanism of the leaching process. Based on a comparison with H₂O₂ with respect to leaching efficiency, the optimal leaching parameters, and the activation energy, we determined that it is feasible to replace H₂O₂ with SnCl₂ as a leaching reductant in the leaching process. In addition, when SnCl₂ is used in the acid-leaching process, Sn residue in the leachate may have a positive effect on the re-synthesis of nickel-rich cathode materials. Therefore, the results of this study provide a potential direction for the selection of reductants in the hydrometallurgical recovery of valuable metals from spent LIBs.     

Investigation on the electrochemical activation process of Li1.20Ni 0.32Co0.004Mn0.476O2

The lithium-rich layered oxides are one of the most attractive cathode materials for lithium-ion batteries.Here,two types of Li1.20Ni0.32Co0.004Mn0.476O2 were synthesized using Li2CO3 and LiOH as lithium sources.An electrochemical activation process occurs in Li1.2Ni0.32Co0.004Mn0.476O2 prepared from Li2CO3(LLO-1),while no obvious activation in Li1.2Ni0.32Co0.004Mn0.476O2 prepared from LiOH(LLO-2) is observed.Via advanced scanning transmission electron microscopy(STEM),we found that Li2MnO3-like structure is rich in the surface region of LLO-2.The study provides a direct explanation for the electrochemical activation of lithium-rich materials.The sample with more LiMO2-like phase at the surface region shows a better cycling performance.It is likely that more LiMO2-like phase at the surface region could stabilize the interface and improve the cycling performance of the Li-rich cathode materials.     

Nanometer properties of oceanic polymetallic nodules and cobalt-rich crusts

An ammonia leaching process was utilized to extract Co, Ni and Cu from oceanic polymetallic nodules, whereas an acid leaching process was utilized to extract Co, Ni, Cu, Zn and Mn from cobalt-rich crusts. Both processes produced nanometer materials—ammonia leaching residue and acid leaching residue. A systematic study was conducted on the phase, composition and physicochemistry properties of these residues. The result shows that both residues contain a large amount of nanometer minerals. Ammonia l eaching residue mainly consists of rhodochrosite, with the average grain diameter of 17.9 nm; whereas the acid leaching residue mainly consists of well-developed bassanite, with the average grain deameter of 9.5 nm. The bassanite also has a microporous structure, the volume of the pore space is 1.23 × 10⁻² mL/g. Both the ammonia and acid leaching residues have a large specific surface area, and they display a strong adsorption capacity to saturate sodium chloride vapour, N₂ and SO₂. Both residues have high contents of rare earth elements, and most of these elements exist in the state of ionic adsorption. The content of σ FeO is high. The P₂O₅ enrichment is observable in acid leaching residues. The unique composition and nanometer solid properties of the leaching residues displayed their potential value and promised a bright future for their application in the field of environmental protection and materials.