钢铁盐酸酸洗废液资源化利用：电解法制备纳米氧化铁的研究

发布时间：2018-03-14 17:07

  本文选题：钢铁盐酸酸洗废液　切入点：资源化　出处：《浙江大学》2017年硕士论文　论文类型：学位论文

【摘要】：盐酸作为钢铁酸洗工序常用的酸洗清洁剂被钢铁生产企业大量使用。我国每年产生大量的钢铁盐酸酸洗废液,国内已将其列入危险废物名录。目前常规的处置方式以石灰乳中和、蒸馏回收盐酸、铁系混凝剂制备等方法为主,但从资源利用的角度来讲却是经济性欠佳。本文以钢铁盐酸酸洗废液为研究对象,设计了专门的电解试验装置,探究以电解法处理钢铁盐酸酸洗废液,以废液中的铁离子为原材料,制备高附加值纳米氧化铁,从而提高钢铁盐酸酸洗废液的资源化利用效率。本文设计了一个由阳离子交换膜分隔成两室的电解试验装置,以钌铂钛合金作为阴阳电极,阳极室添加过滤之后的低酸度钢铁盐酸酸洗废液,阴极室添加一定浓度的NaCl溶液和分散剂,以外部直流稳压电源提供电流,进行电解法制备纳米氧化铁试验。采用单因素试验法探究了分散剂种类、电流密度、反应温度、煅烧温度等试验条件对纳米氧化铁制备的影响,以TEM图像表征的方式,通过对比粒径、形貌、分散性指标,优化试验条件。再以分散剂用量、电流密度、反应温度、煅烧温度为指标,进行四因素三水平的L9(34)正交试验,并以纳米氧化铁产品质量(g)、Fe2O3含量(%)、电流效率(%)以及粒径(nm)为指标,探究纳米氧化铁制备的最佳试验条件,最后以最佳试验条件制备纳米氧化铁并进行相应表征。通过单因素电解试验,电流密度确定在80A/m2上下;相对而言,单独添加聚乙二醇的分散效果更优;反应温度初步确定为20～30℃;煅烧温度大约为600℃。正交试验结果显示,产品质量、Fe2O3含量、电流效率和粒径的显著性影响因素分别为电流密度、反应温度、分散剂用量与煅烧温度。通过正交试验结果与直观分析数据的分析,确定最佳试验条件为分散剂采用聚乙二醇,添加量为1.0g,电流密度100A/m2,反应温度30℃,煅烧温度600℃。最佳试验条件下制备得到椭圆短棒状纳米氧化铁微粒,经XRD分析确定晶型为α-Fe2O3。平均粒径为68nm,Fe2O3含量可达99.53%,此两项指标可达到《工业氧化铁(HG/T2574-2009)》合格品以上的要求,且Fe2O3含量单项指标还可以满足《氧化铁颜料(GB/T1863-2008)》氧化铁颜料红A类的要求;电流效率达到了 91.80%,Fe回收率为34.89%。
[Abstract]:Hydrochloric acid is widely used in iron and steel enterprises as the common acid cleaning agent in iron and steel pickling process. A large amount of acid pickling liquid of iron and steel is produced every year in China. It has been listed in the list of hazardous wastes in China. At present, the usual methods of disposal are lime milk neutralization, distillation and recovery of hydrochloric acid, preparation of ferric coagulant, etc. However, from the point of view of resource utilization, it is not economical enough. In this paper, a special electrolytic test device is designed to deal with the acid pickling waste of iron and steel hydrochloric acid by electrolytic method, taking the acid pickling liquid of iron and steel hydrochloric acid as the research object. Using iron ion in waste liquid as raw material, high value-added nanometer ferric oxide was prepared to improve the utilization efficiency of iron and steel hydrochloric acid acid pickling waste liquid. An electrolytic test device separated by cation exchange membrane into two chambers was designed in this paper. Ruthenium platinum-titanium alloy was used as the cathode electrode, the anodic chamber was filled with filtered low-acidity acid acid pickling liquid of iron and steel, and the cathode chamber was filled with certain concentration of NaCl solution and dispersant. The current was provided by external DC power supply. The effects of the kinds of dispersant, current density, reaction temperature and calcination temperature on the preparation of nanometer iron oxide were investigated by single factor method. By comparing particle size, morphology, dispersity index, optimizing test conditions, and taking dispersant dosage, current density, reaction temperature and calcination temperature as indexes, the orthogonal test was carried out at four factors and three levels. Taking the content of Fe _ 2O _ 3, current efficiency and particle size of nanometer iron oxide as the index, the optimum experimental conditions for the preparation of nanometer iron oxide were studied, and the content of Fe _ 2O _ 3 and the content of Fe _ 2O _ 3 in nanometer iron oxide were studied. Finally, the nanometer ferric oxide was prepared under the optimum experimental conditions and characterized accordingly. The current density was about 80 A / m ~ 2 by single factor electrolysis test, and the dispersion effect of adding polyethylene glycol alone was better. The reaction temperature is 20 ~ 30 鈩，

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