【作者】 李明艳；

【导师】 陶长元；

【作者基本信息】 重庆大学 ， 化学， 2010， 硕士

【摘要】 电解锰渣是硫酸法浸取碳酸锰矿制备电解锰液后产生的一种含水率高的固体废弃物。近些年来,随着我国电解锰工业的快速发展,电解锰废渣的处理和资源化利用问题日益突出。目前,由于经济和技术等原因许多电解锰企业对电解锰渣并未做任何处理而将其直接堆放于渣场,但经过长期堆积这些废渣会对周围环境造成严重污染。因此锰渣的综合利用不但可以消除环境污染,而且还能够创造巨大的经济效益,是可持续发展的有效途径。本文针对重庆某公司生产的电解锰渣,首先利用多种分析手段从电解锰渣资源化利用的角度对其基本性质进行了初步分析,在此基础上分别对锰渣预处理、回收锰及回收氨氮的工艺过程及条件进行探索和讨论,并检测和评价了剩余残渣的资源化利用情况。结论如下:电解锰渣颗粒比较细,粒径大部分在80μm以下。它主要包括二水石膏相、石英相、软锰矿相及水锰矿相等矿相;渣中主要含有Si、Al、Fe、N、Mn、Ca等元素,以氧化物计算含量如下:二氧化硅(35.43%)、三氧化二铝(11.48%)、三氧化二铁(5.40%)、硫酸铵(7.9%)、一氧化锰(3.79%)、氧化钙(8.44%);锰渣中所含元素种类较多,主要是针、柱状外形规则晶体颗粒与其他物质形成的混杂交织堆积结构,各种特征颗粒之间交错搭接。在洗渣过程中,探索了浸锰的方法和条件,确定了清水作为浸取剂的可行性及相应工艺条件。通过实验可知:当m(渣):v(水)=1:5时,常温搅拌下反应2 h,电解锰渣中Mn2+的浸出率可达到93.8%。在回收锰阶段,采用碳酸锰沉淀法回收溶液当中的二价锰,根据对影响锰回收率各个参数的考察可知,采用碳酸铵做沉淀剂,当n(CO32+):n(Mn2+)=1.3:1,转速为80 r/min,絮凝剂浓度为0.4 mg/L,pH值为7,沉淀时间为60 min时,锰回收率可高达99.8%以上。回收得到的碳酸锰纯度达88.9%,可用此碳酸锰代替锰矿石进行电解锰的生产。采用硫酸铝铵结晶法从电解锰废渣中回收可溶性氨氮,探讨了沉淀剂投加量、反应温度、pH值及时间对氨氮回收率的影响,结果显示:在n((NH4)2SO4):n(Al2(SO4)3)= 1:1,溶液pH 2.5,反应温度95℃,反应时间2 h的条件下,氨氮回收率可高达95.2%以上。且所得晶体颗粒呈无规则形状,分散性能良好,无团聚现象,其纯度达93.1%。探究了不同水洗时间对硫酸盐溶解特性的影响。实验表明,当水洗时间为60 min时,渣中可溶性硫酸盐已基本溶解。更多还原

【Abstract】 Electrolytic manganese residue, containing high water content, is a kind of industrial solid waste generated from leaching manganese carbonate with sulfuric acid. In recent years, with the rapid development of electrolytic manganese industry in China, it has increasingly become a critical problem about the treatment and utilization of electrolytic manganese residue. At present, due to the economic and technical reasons, most of the electrolytic manganese residues are deposited in store yards without any treatment. By the accumulation, the untreated waste residue becomes seriously dangerous pollution sources for the environment. Therefore, comprehensive utilization of electrolytic manganese residue can not only reduce environmental pollution, but also bring huge benefits. And it is an effective way for sustainable development.In this thesis, the electrolytic manganese residue was from a plant in Chongqing. In order to utilize the electrolytic manganese residue, various analytic methods were required to characterize its basic properties firstly. Secondly, based on the analysis results, the process and its operation conditions on the electrolytic manganese residue pretreatment, manganese and ammonium recovery were studied. At last, the utilization on the residue from the second procedure above was analyzed and evaluated.Conclusions are as follows.The particle size of electrolytic manganese residue is small, and most particle is less than 80μm. It is mainly composed of gypsum phase, quartz phase, pyrolusite phase and manganite phase, etc., and the elements mainly contain Si、Al、Fe、N、Mn、Ca, of whose percentage calculated by the content of oxide are as follows,silica (35.43%), aluminum oxide (11.48%), ferric oxide (5.40%), ammonium sulfate (7.9%), manganese oxide (3.79%), calcium oxide (8.44%). Kinds of elements are contained in the electrolytic manganese residue, which mainly presents mixed stacking structure formed by needle, columnar shaped crystal particles with other substances,and the various particles are staggered and overlapped with each other.The new method’s conditions on leaching manganese from the residue were studied in the process of washing. And the feasibility with distilled water as the leaching agent was identified. By the experiments, It is known that when m(residue): v(distilled water) = 1:5, the reaction stirred at room temperature for 2h, the leaching rate of manganese element from manganese residue reaches 93.8%. In the stage of recovery manganese, divalent manganese in the solution could be recovered through manganese carbonate precipitation. During the precipitation with ammonium carbonate as the precipitant, the factors impacting the recovery of manganese were investigated, The results show that when n(CO32+):n(Mn2+)=1.3:1,C(flocculant)=0.4 mg/L,pH =7, stirring speed is 80 r/min and reaction time reaches60 min, the recovery rate of Mn2+ is up to 99.8%. The purity of the recovered manganese carbonate comes to 88.9%, which can be used to produce electrolytic manganese instead of manganese ore well.In the stage of recovering soluble nitrogen from electrolytic manganese residue, aluminum ammonium sulfate crystallization was applied, and the influence of precipitant dosage, reaction temperature, pH value and reaction time on ammonia nitrogen recovery rate was discussed. The results show that when n((NH4)2SO4):n(Al2(SO4)3)= 1:1,pH =2.5, reaction temperature is 95℃, and reaction time maintains 2h, the recovery rate of ammonia nitrogen is more than 95.2%. And the crystal particles obtained are of irregular shape, with good dispersion, no agglomeration, and the purity is up to 93.1%.The impact of different washing time on characteristics of dissolved sulfate was explored. Results show that when the washing time is 60 min, the soluble sulfate in electrolytic manganese residue has been almost dissolved.更多还原