稀土冶炼氨氮废水的处理技术现状

分析了稀土冶炼废水产生原因和组成成分,阐述了国内外稀土冶炼氨氮废水主要处理技术及研究现状,分别介绍了生化法、物化法及蒸馏法等处理技术原理,讨论了这些稀土冶炼氨氮废水处理技术实际运用中存在的问题.并着重针对目前风化壳淋积型稀土矿提取和分离过程中面临的氨氮达不到废水排放新标准等问题,提出了今后加强对风化壳淋积型稀土矿提取分离新技术工艺及新型药剂等的研究,探索氨氮废水循环利用新途径,从源头消除氨氮废水并从根本上治理氨氮污染.      

Leaching kinetics of ionic rare-earth in ammonia-nitrogen wastewater system added with impurity inhibitors

Ammonia-nitrogen wastewater is produced during the dressing and smelting process of rare-earth ores.Such wastewater includes a very high concentration of NH4＋, as well as other ions（e.g., NH4＋, RE3＋, Al3＋, Fe3＋, Ca2＋, Cl–, and Si O32–） with a p H of 5.4–5.6.Its direct discharge will pollute, yet it can be recycled and used as a leaching reagent for ionic rare-earth ores.In this study, leaching kinetics studies of both rare earth ions and impurity ion Al3＋ were conducted in the ammonia-nitrogen wastewater system with the aid of impurity inhibitors.Results showed that the leaching process of rare-earth followed the internal diffusion kinetic model.When the temperature was 298 K and the concentration of NH4＋ was 0.3 mol/L, the leaching reaction rate constant of ionic rare-earth was 1.72 and the apparent activation energy was 9.619 k J/mol.The leaching rate was higher than that of conventional leaching system with ammonium sulfate, which indicated that ammonia-nitrogen wastewater system and the addition of impurity inhibitors could promote ionic rare-earth leaching.The leaching kinetic process of impurity Al3＋ did not follow either internal diffusion kinetic model or chemical reaction control, but the hybrid control model which was affected by a number of process factors.Thus, during the industrial production the leaching of impurity ions could be reduced by increasing the concentration of impurity inhibitors, reducing the leaching temperature to a proper range, accelerating the seepage velocity of leaching solution, or increasing the leaching rate of rare earths.     

我国伴生硫铁矿浮选技术现状及进展

在查阅大量有关伴生硫铁矿浮选研究文献资料的基础上,分析总结了选矿工作者对黄铁矿、磁黄铁矿等伴生硫铁矿的种类、结构特点与其可浮性的关系研究现状;论述了硫铁矿浮选回收的捕收剂、抑制剂、活化剂的种类及其应用情况;根据铜铅锌硫化矿石伴生硫铁矿中主金属铜铅锌的浮选工艺及特点,阐述了伴生硫铁矿的主要浮选工艺及其应用情况。为提高伴生硫铁矿的综合回收水平,一方面在回收铜铅锌等主金属时尽量减少对硫铁矿的强烈抑制,为硫铁矿的活化浮选创造条件,另一方面,加强受抑制硫铁矿活化剂、捕收剂及先进工艺的研制及开发。