【作者】 霍广生；

【导师】 李洪桂； 孙培梅； 赵中伟；

【作者基本信息】 中南大学 ， 冶金科学与工程， 2001， 博士

【摘要】 针对钨冶炼过程中钨钼分离这一亟待解决的技术难题进行了较为深入的研究。在大量的理论分析、试验研究及前人思路的基础上，成功地开发出了一种高效、简便的钨钼分离新工艺，目前该工艺已被成功地应用于工业生产。 本文的主要内容概括如下： 1)对钨酸盐溶液中钼的硫化行为进行了系统而全面的研究。 首次对钨酸盐溶液中钼的硫化反应进行了热力学分析，绘制了MoO_xS_4-x^2-随溶液中pH值及硫化剂用量[S]／[Mo]变化的分布曲线，分析了溶液中pH值及硫化剂用量对钼的硫化行为的影响规律，为钼的硫化实践提供了理论指导。 通过试验研究进一步查明了钨酸盐溶液中钼的硫化行为，并确定了合理的钨酸盐料液中钼的硫化条件。 2)针对现有的强碱性阴离子交换树脂除钼工艺和季铵盐萃取除钼工艺中MoS42-难以解吸或反萃的缺陷，进行了一系列的改进性研究。 首先，研究了弱碱性阴离子交换树脂对MoS42-的吸附及用NaOH溶液解吸的行为，结果表明：D301树脂（叔胺）虽具有较好的吸附交换能力，但用NaOH溶液解吸时效果不理想；而D312树脂（伯胺）虽然用NaOH溶液解吸时具有较好的解吸效果，但其吸附交换能力却很弱。因此，在基于MoS42-同WO42-性质差异而进行的离子交换除钼工艺中，试图以弱碱性阴离子交换树脂取代强碱性阴离子交换树脂，并以NaOH溶液作为解吸剂以避免使用氧化剂NaClO作为解吸剂的方案是由困难的。 其次，研究了二元萃取（以N263+P204+TBP+磺化煤油为萃取体系）工艺中MoS42-的萃取及反萃行为，试验结果表明：随着P204加入量的增加，钼的萃取率逐渐越低，而其反萃率呈上升趋势。但是，P204的加入使N263对MoS42-的萃取能力大大降低，其萃取效果很不理想，无实际应用意义。因此，试图通过二元萃取的方法来解决N263萃取MoS42-后的反萃困难的效果是很不理想的。 最后，研究了利用离子浮选法分离钨钼，试验结果表明：将含钼的（NH4）2WO4或Na2WO4料液硫化后，以十六烷基三甲基溴化铵为捕收剂进行离子浮选，可以获得很好的效果，并能生产出Mo／WO3＜20×10-6的0级APT。但是，该工艺中捕收剂的回收困难，除钼过程的钨损较高，因此还无法应用于工业实践。 3)在深入研究了WO42-和MoS42-微观性质差异的基础上，开发了新的钨钼分离试剂及工艺，并将其拓展到了除砷、锡、锑等杂质。研究结果表明： ①MoS42-的最高占据轨道HOMO的轨道能量比WO42-的要高4.85eV，这说明填充在MoS42-分子的HOMO中的电子将具有更大的流动性，并使得MoS42-将表现出更好的配位性；同时计算结果表明，对于MoS42-分子，其HOMO主要由4个S原子的原子轨道组成，因此MoS42-分子的HOMO在化学反应中将主要表现出S的性质。而对于WO42-分子，其HOMO主要由4个O原子的原子轨道组成，因此WO42-分子的HOMO在化学反应中将主要表现出O的性质。 ②将MoS42-与硫化矿捕收剂进行了对比，结果表明二者具有很大的相似性。因此本研究中将MoS42-视作硫化矿捕收剂，进而选择了CuS、NiS、CoS、PbS、FeS、ZnS和HgS等几种有色金属硫化物作为钨钼分离的可能新试剂。 通过理论分析及试验研究证实，CuS、NiS、CoS和PbS均具有很好的除钼 摘 要效果，且基本不与 WO／作用，能够实现钨铝的有效分离。在其用量为 3～4理论量的条件下，在室温下搅拌 1小时后除铝率均可达 96％以上。综合考虑经济。资源及环保等因素，最终确定CllS为最为合理而高效的钨铝分离新试剂，并确立了“选择性沉淀法除铝新工艺”。 ③理论分析表明，钨酸盐溶液中的 AsO／’、SnO／“、SbO／‘具有硫化为相应的硫代酸根的可能性。进一步的计算表明，砒民、幼、‘＼既民‘－等分子的微观性质与 Md4‘’具有很大的相似性，并基本符合作为硫化矿捕收剂的条件。 试验结果表明，在对含上述杂质的钨酸盐溶液进行适当地硫化处理后，利用CllS能够很好地将上述杂质除去，除杂率均在 80％以上。从而成功地将“选择性沉淀法除铝新工艺”拓展到了除砷、锡、锑等杂质，并最终初步形成了能够一次性除去多种杂质的“选择性沉淀法除除铝、砷、锡、锑新工艺”，现己在国内广为推广应用，占国内市场的69％左右。更多还原

【Abstract】 The difficult problem of removing molybdenum from tungstate in the process of tungsten metallurgy has been studied in depth. Based on a lot of theoretical analysis and experimental investigation, a very effective and simple new technics of removing molybdenum from tungstate has been invented successfully. And we have put it into practice in the industrial production.The main content of this paper is:1) The behaviour of molybdenum sulfidation in tungsten solution has been investigated in detail.At first, the thermodynamic analysis of the molybdenum sulfidation was done, and the curves, which describe the distribution of MoOxS4.x2" according to the change of solution pH and sulfurizing reagent amount, has also been ploted. These work provided theoretic instruction for the practice of molybdenum sulfidation.Secondly, through the experimental investigation, the behaviour of molybdenum sulfidation was studied again, and the proper conditions of sulfurizing molybdenum in tungstate solution were put forward finally.2) Some existent technics of removing molybdenum from tungstate, such as ion-exchange technics by using of strong base anion ion-exchange resin or solvent extraction technics by using of quaternary ammonium salt, have a very great defect, that is desorption or back extraction of MoS42" is very difficult to complete . In order to overcome this defect, some new research was done in this paper.At first, the adsorption and desorption behaviour of MoS42" by using of alkalescent anion ion-exchange resin was studied, the experiment result shows that: D301 ion-exchange resin’s (with tertiary amine radical) effect of absorbing MoS42" is better, but the effect of desorbing MoS42" with NaOH solution is not satisfying. On the contrary, although D312 ion-exchange resin’s (with primary amine radical) effect of desorbing MoS42" with NaOH solution is better, it’s effect of absorbing MoS42" is very bad. So by using of alkalescent anion ion-exchange resin can not overcome the defect that mentioned before.Secondly, the behaviour of extration and stripping of MoS42" in synergistic extraction technics (N263+P2o4+TBP+Coal oil) is studied, the experiment result shows that: With the increasing of P2o4 added into the extraction system, the extraction efficiency of MoS42" become small gradually, but the stripping efficiency of MoS42" increases gradually. Because the addition of P2o4 reduces the N263’s capacity of extracting MoS42" greatly, this technics has no practical valule. So it is impossible to overcome the defect mentioned before by using synergistic extraction technics studied here.Finally, the method of revoming molybdenum from tungstate by using ion flotation technics was studied, the experiment result shows that: After the (NH4)2WO4 or Na2WO4 solution has been sulfurized, it is very effective of removing molybdenum from tungstate by using cetyl trimethyl ammonium bromide as ion flotation collector.Through this technics, the ammonium paratungstate(APT) in which the Mo/WO3 is under 20 X 10"6 can be produced. But how to reclaim the collector is very difficult in this technics.3) Based on the investigation of WO42" and MoS42"’s difference in microscopic property, the new reagent and technics for revoming molybdenum from tungstate have been invented, and it has been extended to revoming As, Sn and Sb from tungstate. The research work shows that:(T) The highest occupied molecular orbital energy HOMO of MoS42" is much higher than that of WO42"(the energy difference of them is 4.85eV), this indicates that the electrons are more liable to lose when the molecule react with the others, and it will shows the better coordinating ability; At the same time the result shows that, the highest occupied molecular orbit of MoS42~ is composed of Mo atom’s orbits, but the highest occupied molecular orbit of WO42"is composed of W atom’s orbits.Comparing MoS42" with the flotation collectors of sulphidic ore, we found that they are very similar to each other. So we regarded MoS42" as the flotation collectors o更多还原