钢铁冶金烧结灰中铅的浸取回收和一氧化铅的制备

发布时间：2018-03-11 03:07

  本文选题：烧结除尘灰　切入点：盐酸-氯化钠溶液　出处：《湘潭大学》2015年硕士论文　论文类型：学位论文

【摘要】：烧结机头电除尘灰(简称烧结灰)作为钢铁固废之一,来源于钢铁生产烧结工艺过程中电除尘器的烟气收集。烧结灰中化学成分复杂,除铁元素之外,有的还含钾、铜、锌、铅等有害元素。本文依据烧结灰的理化特性分析,开发了盐酸-氯化钠法和醋酸-醋酸钠法提取烧结灰中铅的工艺路线。研究了烧结灰理化特性,发现烧结灰中Pb的平均含量为4.77%,主要以PbO、PbOHCl形式存在;粒度分析得出1#、2#、3#烧结灰的中位直径分别为39.84μm、23.84μm、18.34μm,比表面积分别为19.6 m2/g、15 m2/g、17.5 m2/g;结合先前的相关研究,决定先将烧结灰水洗脱钾,在磁选选铁并富集铅,最后再湿法提铅。通过磁选后,富铅尾泥中的铅含量为9%~12%,采用盐酸-氯化钠浸取烧结灰中铅,在温度为85~90℃、氯化钠浓度为250 g/L、工业盐酸用量为25 mL/100 g(烧结灰)、富铅烧结灰(尾泥)与HCl-NaCl混合溶液的固液比为1.0:3.0、浸取时间为30 min的条件下,浸取过程中铅的浸取率在99.50%以上;冷析母液循环使用2次,铅的总回收率达95.08%;碳酸钠的加入量为其理论量的0.90~1.0倍,铅的沉淀率为99.90%,转化得到的沉淀在温度为650℃条件下煅烧5 h,得到的一氧化铅产品纯度为99.50%,达到HG/T 2325-2004标准中工业一级品的指标要求,整个工艺流程铅的回收率为64.77%。将铅含量为9%~12%富铅尾泥进行氯化脱杂,得到氯化后的富铅尾泥,其中Cu、Zn已基本脱除,Ca、Mg的含量也低于0.2%不影响后续实验,铅含量基本保持不变。通过醋酸-醋酸钠浸取氯化后灰中铅,在温度为室温(25℃),醋酸钠浓度为2 mol/L,醋酸浓度为0.5 mol/L,富铅烧结灰(尾泥)与HAc-NaAc混合溶液固液比为1:2,浸出时间为30 min,搅拌速率为300 r/min的条件下,氯化后灰中铅的浸出率可以达到99.80%;碳酸钠的加入量为其理论量的0.90倍,铅的沉淀率为99.90%,转化得到的沉淀在温度为650℃条件下煅烧5 h,得到的一氧化铅产品纯度为99.60%,达到HG/T 2325-2004标准中工业一级品的指标要求;冷析母液循环使用5次,铅的总回收率达99.8%,整个工艺流程铅的回收率为67.33%。经初步估算,若按盐酸-氯化钠工艺对烧结灰进行铅回收生产,年产值可达116.83万元,按醋酸-醋酸钠工艺对烧结灰进行铅回收生产,年产值可达202.08万元,表明两种工艺具有很好的回收经济效益。
[Abstract]:As one of the solid wastes of iron and steel, the electric dust remover of sintering machine head (abbreviated as sinter ash) is derived from the collection of flue gas from the electrostatic precipitator in the sintering process of iron and steel. The chemical composition of the dust is complex, besides iron elements, some of them also contain potassium, copper and zinc. Based on the analysis of the physical and chemical properties of sintered ash, the technological routes of extracting lead from sintered ash by hydrochloric acid-sodium chloride method and acetic acid-sodium acetate method were developed, and the physical and chemical properties of sintered ash were studied. It was found that the average content of Pb in the sintered ash was 4.77, mainly in the form of PBOHCl, and the particle size analysis showed that the median diameter of the sintered ash was 39.84 渭 m ~ (23.84) 渭 m ~ (23. 84) 渭 m ~ (-1) and the specific surface area was 19.6 m ~ (2) / g ~ (15 m ~ (2)) 路g ~ (17. 5) 路m ~ (2 / g). After magnetic separation, the lead content in lead-rich tailings is 9 ~ 12. The lead in sintered ash is extracted by hydrochloric acid and sodium chloride, and the temperature is 85 ~ 90 鈩，

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