Structure and electrochemical performance of spinel LiMn2O4 synthesized by mechanochemical process

1　INTRODUCTIONLithium ion battery was used in many areasbecause of its high voltage, high energy densityand long cycle life and so on. Spinel lithium man ganese oxide was one of the most promising mate rials in term of its environmental benign, low cost,easy preparation and temperature safety. Mainproblem is the poor cycle life. As we all know thatboth the structure and electrochemical performanceof material strongly depended on the preparingmethod and starting…     

Thermodynamic analysis on sodium carbonate decomposition of calcium molybdenum

According to the principle of mass balances and thermodynamic data, 1g [Me]-pH diagrams （Me=Ca, Mo） for Ca-Mo-CO3-H2O system at 25 ℃ were presented with total dissolved carbon-containing ions concentrations of 0.01 mol/L and 1 mol/L, and 1g [Me]-pH diagram for Ca-Mo-H2O system at 25 ℃ was also depicted. The effects of system pH value and total dissolved carbon-containing ions concentrations on the concentrations of the species in Ca-Mo-CO3-H2O system were studied. The results show that the stability region of CaMoO4 reduces significantly in the presence of sodium carbonate. In order to achieve effective leaching of molybdenum from CaMoO4, a certain concentration of sodium carbonate is necessary. High total dissolved carbon-containing ions concentrations and high pH values facilitate to the leaching of CaMoO4 and dissolved sodium carbonate is an efficient leaching agent for decomposing CaMoO4.     

Mechanism explanation for SO_2 oxidation rate of Cs-Rb-V series sulfuric acid catalyst at low temperature

1　ＩＮＴＲＯＤＵＣＴＩＯＮＣｓ Ｒｂ Ｖｓｅｒｉｅｓｃａｔａｌｙｓｔｉｓａｎｅｗｌｙｄｅｖｅｌｏｐｅｄｓｕｌ ｆｕｒｉｃａｃｉｄｃａｔａｌｙｓｔｕｓｅｄｕｎｄｅｒｌｏｗｔｅｍｐｅｒａｔｕｒｅ .Ｉｔｓｉｎｉｔｉａｌｃｏｍｂｕｓｔｉｏｎｔｅｍｐｅｒａｔｕｒｅｉｓ 30～ 50℃ｌｏｗｅｒｔｈａｎｃｏｍｍｏｎｓｕｌｆｕｒｉｃａｃｉｄｃａｔａｌｙｓｔ ,ｔｈａｔｉｓｔｏｓａｙｔｈａｔｉｔｓｉｎｉｔｉａｌｃｏｍｂｕｓｔｉｏｎｔｅｍｐｅｒａｔｕｒｅｃｏｕｌｄｂｅｒｅｄｕｃｅｄｔｏａｂｏｕｔ 370℃ａｎｄｉｔｓｎｏｒｍａ…     

面向生产主战场为我国钨湿法冶金技术赶超世界先进水平而努力

介绍了中南大学冶金科学与工程系冶金过程强化学科组20年来在复杂钨矿物原料碱分解及从钨酸盐中除钼等杂质的研究成果及其产业化情况,总结了有关的经验。     

浸出过程的理论基础及实践

1.1 搅拌浸出 搅拌浸出法为冶金中应用最广的浸出方法,其实质是将原料充分磨细后（0.04～0.1mm）与浸出剂混合,在激烈搅拌并保证一定温度的条件下进行反应。因而两相间接触面积大,传质条件好,浸出速度快。     

选择性氯化法分离钛铁矿的热力学分析

运用热力学数据和热力学计算方法,绘制出Fe-Ti-O-Cl系不同温度下的热力学平衡图,运用热力学平衡图分析了钛铁矿选择性氯化的热力学条件。     

反应挤出法碱分解黑钨矿

针对目前黑钨矿碱法分解工艺中存在的反应温度高、生产效率低等问题,开发了一种黑钨矿碱分解新工艺,以双螺杆挤出机为反应器,采用反应挤出法对高黏度黑钨矿的碱分解过程进行了研究,系统考察浸出时间、温度、螺杆转速和碱用量对钨矿浸出效果的影响。在矿水质量比为2.67:1、碱用量为理论量的1.5倍、温度为120℃,螺杆转速为180 r/min和反应时间为2.5 h的条件下,浸出渣中WO3的含量为2.54%,钨矿的浸出率达99.13%。     

矿物机械活化基础理论的研究进展

详细介绍了矿物机械活化基础理论研究的进展。     

Preparation of calcium phosphate coating on pure titanium substrate by electrodeposition method

The influences of pH value, electrolyte temperature and loading time on depositing calcium phosphate coating on pure titanium substrate by electrodeposition process were investigated. The process was carried out with an electrochemical work-station supplying a direct current power at potential of -0.8V (vs SCE). The electrolyte consists of 7 mmol·L-1 CaCl2·2H2O, 3 mmol·L-1 Ca(H2PO4)2·H2O and 2.5% H2O2. NaOH and HCl solutions were used to adjust pH value. The deposited samples were characterized by X-ray diffraction and scanning electron microscope. The comparison of the deposits obtained at lower and higher pH values demonstrates that the crystallization process at the interface is favoured by high pH value. With temperature increasing, the deposited hydroxyapatite is occasionally of plate-like shape, and the width and the length of the deposited calcium phosphates at 65 ℃ are larger than those at 55 ℃. Therefore, it is confirmed that the morphology and microstructure of electrochemically deposited calcium phosphates can be regulated. Additionally, the coating formed in electrolyte with H2O2 additive is homogeneous and the evolution of H2 bubble can be eliminated.     

变参数离子交换的原理及其在钨冶金中的应用

通过理论分析掌握了动态离子交换时被吸附离子在交换柱内的分布规律及其影响因素,在此基础上提出了变参数离子交换的新观念并阐明其原理,同时以钨冶金中的应用实例证明了变参数离子交换法的优越性。