超重力条件下强化废铅酸电池铅膏脱硫过程研究

发布时间：2018-01-04 03:17

  本文关键词：超重力条件下强化废铅酸电池铅膏脱硫过程研究　出处：《北京化工大学》2015年硕士论文　论文类型：学位论文

  更多相关文章： 超重力旋转填充床 快速脱硫 强化传质 铅膏 废旧铅酸蓄电池

【摘要】：铅膏是铅酸蓄电池中重要的含铅物质,是铅回收工艺的主要原料,对其处理不当将严重污染环境和危害人类健康。目前,湿法处理工艺由于具有能耗低环境污染小等优点越来越受到广泛关注。然而,传统的湿法处理铅膏过程受扩散控制,液固相间的混合和传质效率低,从而限制了其工业应用。本论文首次将新型过程强化设备超重力旋转填充床应用于铅膏脱硫过程,旨在实现连续快速高效脱硫；进一步通过对其微观混合和传质机理的理论分析,揭示其脱硫过程机制。全文的主要研究内容和结论如下：1)在传统搅拌釜(STR)中,以Na2CO3口NaOH作为脱硫转化剂,进行了PbSO4的脱硫过程研究。重点考察了浓度、物料配比(脱硫剂和PbSO4的摩尔比)、温度等对PbSO4脱硫过程的影响规律。结果表明：随着脱硫转化剂浓度的增加,PbSO4的脱硫率也随之增加；随着物料配比的提高,脱硫率也同样增加,当脱硫剂过量20%时,脱硫效率最佳；温度对脱硫过程影响小。此外,当Na2CO3为脱硫剂时,12 min(720 s)后脱硫率为99.7%；而当NaO H为脱硫剂时,6 min(360s)后脱硫率为99.5%。2)采用超重力旋转填充床(RPB)为强化脱硫反应器,进行了PbSO4脱硫过程研究。分别考察了转速、进料流量、物料配比、温度、浓度等因素对脱硫过程的影响。研究发现：脱硫率随着浓度、转速、进料流量的提高均有不同程度的提升,在转速1500 rpm、进料流量1100 mL/min条件下可达到较优脱硫效果。当Na2CO3为脱硫剂时,低浓度下提高温度可提高脱硫率,继续提高则将导致脱硫率的下降,但高浓度下温度的影响不显著；当NaOH为脱硫剂时,随着温度的升高,脱硫率呈先降低后升高的趋势,20℃时达到最高脱硫率。按化学计量比计算,当Na2CO3过量20%和NaOH不过量时,均可实现高效快速脱硫,即在1 s的反应时间内,脱硫率达到99.5%,较STR缩短了2个数量级,更重要的是实现了连续化操作。3)基于RPB内PbSO4脱硫的较优工艺条件,进一步开展了RPB处理实际铅膏负极粉和正极粉的脱硫过程研究。对比研究发现,在STR中,对于Na2CO3体系,在9000 rpm转速下反应10min (600 s),脱硫率为97%；对于NaOH体系,14 min (840 s)后脱硫率为99%。而在相同温度、浓度和物料配比等实验条件下,RPB(转速1500rpm)实现同样的铅膏脱硫率,所用时间仅需1 s,至少提高2个数量级。上述研究结果表明,本论文提出的超重力旋转填充床强化废铅酸电池铅膏的脱硫技术,具有重要的工业应用价值。
[Abstract]:Lead paste is an important lead-containing substance in lead-acid batteries and the main raw material of lead recovery process. Improper treatment of lead paste will seriously pollute the environment and endanger human health. Due to its advantages of low energy consumption and low environmental pollution, wet process has attracted more and more attention. However, the traditional wet treatment of lead paste process is controlled by diffusion, and the mixing and mass transfer efficiency between liquid and solid phases is low. Therefore, its industrial application is limited. In this paper, a new type of process strengthening equipment, hypergravity rotating packed bed, is first applied to the desulfurization process of lead paste in order to realize continuous rapid and efficient desulfurization. The mechanism of desulphurization is revealed through the theoretical analysis of its micro-mixing and mass transfer mechanism. The main contents and conclusions of this paper are as follows: 1) in the traditional stirred kettle (STR). The desulfurization process of PbSO4 was studied with Na2CO3 port NaOH as desulfurization conversion agent, and the concentration and molar ratio of material (desulfurizer and PbSO4) were investigated. The effect of temperature on PbSO4 desulfurization process. The results show that the desulfurization rate of PbSO4 increases with the increase of desulfurization conversion agent concentration. The desulphurization rate also increases with the increase of the material ratio, and the desulfurization efficiency is the best when the desulfurization agent exceeds 20%. The temperature has little effect on the desulfurization process. In addition, the desulphurization rate is 99.7 when Na2CO3 is the desulfurizer for 12 min(720 s. When NaO H was used as desulfurizer, the desulphurization rate was 99.5%. 2) the high gravity rotating packed bed (NaO B) was used as the enhanced desulfurization reactor. The PbSO4 desulphurization process was studied. The effects of speed, feed flow rate, material ratio, temperature and concentration on the desulfurization process were investigated. It was found that the desulphurization rate varies with the concentration and speed of desulfurization. Under the conditions of 1500rpm rotational speed and 1100 mL/min feed flow, the desulfurization effect was better when Na2CO3 was used as desulfurizer. Increasing the temperature at low concentration can increase the desulfurization rate, and further increasing will lead to the decrease of the desulfurization rate, but the effect of the temperature at the high concentration is not significant. When NaOH was used as desulfurizer, the desulphurization rate decreased first and then increased with the increase of temperature, and reached the highest desulfurization rate at 20 鈩，

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