工业水处理 ›› 2022, Vol. 42 ›› Issue (12): 179-182. doi: 10.19965/j.cnki.iwt.2022-0139

• 经验交流 • 上一篇    

锌冶炼污酸废水循环利用技术研究

刘冰冰1(),季常青2   

  1. 1.新疆紫金有色金属有限公司,新疆克州 845450
    2.厦门紫金矿冶技术有限公司,福建 厦门 361101
  • 收稿日期:2022-10-09 出版日期:2022-12-20 发布日期:2022-12-20
  • 作者简介:刘冰冰(1986— ),硕士,工程师,E-mail: 345005783@qq.com

Study on recycling technology of acid wastewater from zinc smelting

Bingbing LIU1(),Changqing JI2   

  1. 1.Xinjiang Zijin Nonferrous Metals Co. , Ltd. , Kizilsu Kirghiz Autonomous Prefecture 845480, China
    2.Xiamen Zijin Mining & Metallurgy Technology Co. , Ltd. , Xiamen 361101, China
  • Received:2022-10-09 Online:2022-12-20 Published:2022-12-20

摘要:

采用萃取+膜耦合工艺对有色锌冶炼过程产生的污酸废水进行处理。采用4级逆流连续萃取,当有机相组分为25%(体积分数)N235、75%(体积分数)异辛醇,相比为1∶1时,污酸中氯的去除率>98.3%,氟去除率>84.5%。萃取处理后,料液可返回至污酸净化系统循环使用,降低对补充水的需求量。萃取有机负载相经氢氧化钠反萃解吸后循环使用。在反萃液中加入氯化钙,以氟化钙的形式除氟并资源化回收利用;在滤液中先后加入碳酸钠和离子交换树脂,实现钙、镁和重金属离子的深度去除;料液达到双极膜电渗析进料要求后,由双极膜电解技术将精制反萃解吸液转化成混酸和液碱,产生的碱液可用作有机负载相的解吸剂,混酸(盐酸和硫酸混合物)通过纳滤膜实现盐酸和硫酸的分离。回收的稀盐酸可用于软化树脂解吸,硫酸液加入石灰制备石膏产品。与传统的直接中和工艺相比,该工艺的药剂成本低、废液资源化利用水平高,可减少外购药剂。

关键词: 污酸, 萃取, 冶炼废水, 循环利用

Abstract:

A coupled process of extraction and membrane was used for the removal of acid wastewater from a non-ferrous zinc smelting. With four-stage counter-current continuous extraction, when the organic phase components were 25% N235 and 75% isooctanol, phase ratio 1∶1, the removal rate of chlorine was more than 98.3%, and the removal rate of fluorine was more than 84.5%. After the extraction treatment, the wastewater could be returned to purification system for recycling, reducing the demand for make-up water. The loaded organic phase was desorbed by alkali and then recycled. Calcium chloride was added to the stripping solution to remove fluoride in the form of calcium fluoride and recycle it resourcefully. Sodium carbonate and ion exchange resin were added to the filtrate successively to achieve deep removal of calcium, magnesium and heavy metal ions. After the feed solution reached the requirements of bipolar membrane electrodialysis, refined stripping solution was converted into mixed acid and liquid alkali by bipolar membrane electrolysis technology, and the resulting alkali could be used as desorbent for the loaded organic phase. The mixed acid (mixture of hydrochloric acid and sulfuric acid) was separated to hydrochloric acid and sulfuric acid through the nanofiltration membrane. The recovered dilute hydrochloric acid could be used to soften the resin for desorption, and the sulfuric acid was added to lime to prepare gypsum products. Compared with the traditional neutralization process, this process has low chemical cost, high level of waste liquid resource utilization, and reduces cost.

Key words: acid wastewater, extraction, metallurgical wastewater, recycling utilization

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