气相色谱法测定金属钼粉中氧含量

采用氢气还原金属钼粉中的氧,以无水甲醇作吸收液,吸收还原产生的水,应用气相色谱法测定吸收液中水的含量以确定金属钼粉中可被氢还原氧的含量。结果表明,本法测定结果与国标方法测定结果基本一致。方法适用于中小型企业实际生产中金属粉末中氧含量的常规测定。     

钼的硫化反应热力学分析

钨钼分离是钨提取冶金中的1道重要工序．目前工业上应用的分离方法大都基于钨和钼对硫亲和力的差异,在一定条件下使MoO2-4硫化为MoS2-4而进一步除去,因而研究有关硫化反应的理论对于寻找最佳工艺条件有重要指导意义．作者通过热力学计算,对钼的硫化行为进行了考察．研究结果表明为使钼完全硫化,溶液的pH值要低于8;实践中所采用的n(S)=4n(Mo)且溶液中游离0.125mol/L,远超过热力学平衡需要,实际上是考虑到动力学原因;在上述条件下钼可完全硫化．     

钼(Ⅵ)-8-羟基喹啉-5-磺酸-亚硝酸根催化吸附波的研究及应用

在5.0×10-3mol/L的盐酸介质中,钼与8-羟基喹啉-5-磺酸生成的络合物在NaNO2存在下,于-0.30V(vs,SCE)出现一尖锐、灵敏的极谱波.钼含量在0.2～400ng/mL范围内与波高呈线性关系,检测限为0.1ng/mL.用多种电化学方法研究了极谱波的性质及电极反应机理,证明络合波为吸附波.峰电流由中心离子Mo( )还原产生,Mo( )与络合剂的组成比为1∶1.方法用于自来水中痕量钼的测定,快速、灵敏、准确,结果满意.     

Ore-forming event and geodynamic setting of molybdenum deposit at Wenquan in Gansu Province, Western Qinling

The Wenquan molybdenum deposit is associated with a Triassic granite in this area. The Wenquan granite is enriched in LILE and LREE, poor in HFSE, and has significantly higher contents of alkali （K2O＋Na2O） and Sr, Ba than those of the island arc volcanic rocks. These geochemical characteristics are similar to post-collisional granites in high K calc-alkaline series. Studies of major elements, trace elements, REEs and chronology of the Wenquan pluton show that, in the geodynamic transition stage of continent-continent convergence to extension, the partial melting of the enriched lithospheric mantle generated the basaltic magma and triggered the partial melting of the thickened lower crust which produceded the acidic magma, and the Wenquan pluton was formed by mixing of the two magmas. Molybdenite Re-Os isotopic dating gave Os model ages of 212.7±2.6 Ma to 215.1±2.6 Ma with a weighted mean of 214.1±1.1 Ma, and an Re-Os isochron age of 214.4±7.1 Ma. These ages are close to K-Ar ages （223 to 226 Ma） and a SHRIMP zircon U-Pb age （223±7 Ma） for the Wenquan granite within the error range, but relatively younger. This implies that the Mo mineralization occurred in a late stage of the magmatic intrusion, and the metallogenesis took place in the transition stage from syn-collision to post-collision in the tectonic setting of the Qinling Orogenic Belt （QOB） after continental collision between the North China Block （NCB） and the South China Block （SCB）. This process is also corresponding to the geological events of metamorphism and deformation in South Qinling, closure of the Mian-Lue oceanic basin, and exhumation of the Dabie-Sulu ultrahigh-pressure metamorphic rocks. The large-scale continent-continent collision between NCB and SCB in the middle Triassic triggered significant crustal thickening and exhumation of subducted slab. In the late Triassic, the tectonic setting was transformed to the transition stage from collision to extension. Materials from the asthenospheric mantle would ascend into the root of the lower crust, which could induce partial melting of the lower crust and generate Mo-enriched granitic magma. The ore-forming elements enriched in the fluid derived from the condensation and fraction of the magma resulted in the Mo mineralization. The Mo deposits in the QOB are mainly formed in two episodes, namely 220± Ma and 140± Ma. The two episodes of metallogenesis were developed in the tectonic transition settings from compression to extension, but they were in the different stages of the tectonic evolution. The occurrence of the Wenquan Mo-bearing pluton indicates that the Triassic tectonic-magmatic belt of Western Qinling is another favorable region for Mo mineralization in the QOB. Therefore, it is significant to pay more attention to evaluation of the ore-forming potentiality in the Triassic granites in Western Qinling.     

广西全州越城岭花岗岩体东部钨、锡、钼矿产找矿勘查预测探讨

广西全州越城岭花岗岩体东部地区成矿条件好,钨锡（钼）矿化普遍、矿化点密集分布,迄今除个别矿点工作程度相对较高,达到详查外,大部分矿点皆只限于地表矿点勘查或普查,至今只有一个仅具有地方工业价值的小型矿床,其余皆为矿（4C）点。此次的钨锡（钼）成因类型可分高-中温热液型、矽卡岩型二类,越城岭花岗岩体西侧还有含锡矿、绿柱石及铌钽的伟晶岩型。可初步预测预测该区钨〉10万吨．锡〉5万吨,铅锌〉10万吨。     

湿法冶钼新工艺

湿法冶钼新工艺是在焙烧以二硫化钼为主要成份的辉钼矿时,加入一种专用助剂,使二硫化钼中的钼和硫直接焙烧成钼酸钠和硫酸钠,工艺简单、焙烧时间短,全过程既没有二氧化硫产生,也没有三氧化钼生成。     

Mo-30Cu合金室温变形组织

对Mo-30Cu合金室温拉伸性能进行了研究,并对其断口进行观察分析.通过对Mo-30Cu合金冷轧实验,研究了不同变形量下组织的变化规律.结果表明:Mo-30Cu合金的断裂以Cu相的韧性断裂为主,并伴随着Mo/Cu界面的分离和Mo晶粒的解理断裂.Mo/Cu界面的分离和Mo晶粒的解理断裂是Mo-30Cu合金室温轧制过程中产生裂纹的主要原因.     

白光LED用荧光粉Sr_(1-x)Eu_xMoO_4的溶胶-凝胶燃烧法制备及其热稳定性、光学性能

用溶胶-凝胶燃烧法成功制备了Sr1-xEuxMoOt红色荧光粉,mXRD、TEM、荧光磷光分光光度计对其物相、形貌以及发光性能进行表征和研究.结果表明:在395 nm和464 nm两主激发峰均可得到616 nm处红光发射峰,属于Eu3+典型的5Do→7F2的跃迁所致,由464 nm激发得到的发射峰为单峰,峰宽较窄且发射强度较强,粉体平均粒径约为200 nm,颗粒粒度分布均匀.     

镀锌钢上钼酸盐/硅烷复合膜的组成与耐蚀性

分别采用一步法和两步法在热镀锌钢板表面获得钼酸盐/硅烷复合膜,通过X射线光电子能谱分析(XPS)、俄歇电子能谱剥层分析(AES)、盐雾腐蚀试验(NSS)及Tafel极化曲线等对两种复合膜的化学成分和耐蚀性能进行了研究,并将它们与单独的钼酸盐转化膜、硅烷膜进行对比.结果表明:一步法和两步法制备的复合膜具有相似的双层结构,内层以钼酸盐转化膜(含O、Mo、Zn、P)为主,外层以硅烷膜(含C、O、Si)为主,内外层之间及膜与锌基体之间的化学成分呈梯度变化;与单独的钼酸盐膜、硅烷膜相比,两种复合膜对腐蚀的阴极过程的抑制明显增强,自腐蚀电流减小至单层膜的1/5以下,耐蚀性显著提高;两步法制备的复合膜耐蚀性超过常规铬酸盐钝化膜,而一步法制备的复合膜的耐蚀性比由两步法制备的稍差,但仍接近常规铬酸盐钝化膜.     

沙漏型磷钼酸盐的合成表征及其电检测Cr(Ⅵ)性能研究

6价铬离子是具有高致癌性的剧毒污染物之一,可以改变人类DNA转录过程,导致严重的染色体畸变.考虑到Cr(Ⅵ)在生物和环境系统中的高溶解度和迁移性,开发一种廉价灵敏的Cr(Ⅵ)检测方法具有重要的现实意义.通过水热法合成了一例沙漏型磷钼酸盐化合物用于电化学检测Cr(Ⅵ),其分子式为[Mn_2(H_2O)_4Na_4(H_2O)_4]{Mn[P_4Mo_6O_(31)H_7]_2}·13H_2O.实验结果表明,这种晶体对电化学检测Cr(Ⅵ)具有良好的性能.它的线性浓度范围为5～510μmol/L,灵敏度为120μA/(mmol·L~(-1)),检测限低至0.081μmol/L,完全符合世界卫生组织对于水系统中Cr(Ⅵ)的浓度标准,且具有较好的稳定性和抗干扰能力.该研究为在实际的环境水系统中检测Cr(Ⅵ)提供了一种廉价便捷的方法.