高等学校化学学报

• 研究论文 • 上一篇    

“扩散渗析+三步沉淀”组合法资源化处理不锈钢酸洗废水

杨振邈1,吴延楠1,陈京风1,林雅薇1,魏晨杰1.2,刘立芬1,2   

  1. 1. 绿色化学合成与转化技术全国重点实验室,化学工程学院,浙江工业大学 2. 江苏蔚蓝膜分离技术有限公司
  • 收稿日期:2025-12-04 网络首发:2025-12-19 发布日期:2025-12-19
  • 通讯作者: 刘立芬 E-mail:lifenliu@zjut.edu.cn
  • 基金资助:
    浙江省自然科学基金-联合基金-联合重点项目(批准号:LHZ22E080004)和浙江省尖兵领雁+X”科技计划项目(批准号:2025C02241)资助

Recycling Treatment of Stainless Steel Pickling Wastewater by Combination of Diffusion Dialysis and Three-step Precipitation Processes

YANG Zhenmiao1, WU Yannan1, CHEN Jingfeng1, LIN Yawei1, WEI Chenjie1,2, LIU Lifen1,2   

  1. 1. State Key Laboratory of Green Chemical Synthesis and Conversion, College of Chemical Engineering, Zhejiang University of Technology 2. Jiangsu Weilan Membrane Separation Technology Co., Ltd,
  • Received:2025-12-04 Online First:2025-12-19 Published:2025-12-19
  • Contact: LIU Lifen E-mail:lifenliu@zjut.edu.cn
  • Supported by:
    Supported by the Natural Science Foundation Joint Key Project of Zhejiang, China (No. LHZ22E080004) and Zhejiang Province "Jianbing-Lingyan+X" Science and Technology Program (No. 2025C02241)

摘要: 我国是全球最大的不锈钢生产国,不锈钢生产过程会产生大量的酸洗废水,包含高浓度的强酸和重金属盐,若直接排放会严重污染环境,且造成资源浪费,故本论文设计了一种“扩散渗析+三步沉淀”组合法对其进行资源化处理。首先,采用扩散渗析技术将废水中的高浓度混酸(包括HNO3和HF)与废水中的重金属盐(包括铁、铬、镍重金属盐)进行分离以回收混酸,之后采用三步沉淀法对扩散渗析残液中的重金属(包括铁、铬、镍)进行回收,并考察了离子交换膜种类、进料流量(废水)及流量比(扩散侧:渗析侧)对扩散渗析过程混酸回收率和重金属截留率的影响规律,同时优化了三步沉淀工艺包括沉淀剂组成、沉淀温度和pH值等。研究结果表明,扩散渗析的最佳工艺为:采用山东天维公司的TWDDA3S阴离子交换膜,进料流量为6 ml/min(废水),扩散侧与渗析侧流量比为1.5:1,在此条件下硝酸与氢氟酸的总回收率最高可达69.5%,同时铁、铬、镍三种重金属离子的截留率分别达到97.0%、98.0%和96.4%;第一步沉淀的最佳工艺为:复合沉淀剂组成为c(KOH): c(KF)=7:1,沉淀温度为15℃,在此条件下重金属铁、铬的回收率分别达96.2%、90.7%;第二步沉淀的最佳工艺为:采用0.02mol/L HNO3和0.3mol/L KF对第一步沉淀滤液进行深度处理,在此条件下镍离子的保留率和纯度分别达98.7%、89.6%;第三步沉淀的最佳工艺为:通过KOH将滤液pH控制在11左右,在此条件下实现镍的全部回收。

关键词: 不锈钢酸洗废水, 扩散渗析, 三步沉淀, 酸回收, 重金属回收

Abstract: China is the world's largest producer of stainless steel. The production process of stainless steel generates a large amount of pickling wastewater, which contains high concentrations of strong acids and heavy metal salts. If discharged directly, it will seriously pollute the environment and cause resource waste. Therefore, this study designs a combined method of "diffusion dialysis + three-step precipitation" for the recycling treatment of stainless steel pickling wastewater. Firstly, the diffusion dialysis technology was adopted to separate the high-concentration mixed acids (including HNO3 and HF) from the heavy metal salts (including iron, chromium, and nickel heavy metal salts) in the wastewater to recover the mixed acids. Subsequently, a three-step precipitation method was used to recover heavy metals (including iron, chromium, and nickel) from the residual liquid of diffusion dialysis. The influence of ion-exchange membrane type, feed flow (the wastewater) and its flow ratio (diffusion side to dialysis side) were investigated on both the mixed acid recovery rate and heavy metal retention rate in the diffusion dialysis process. Meanwhile, the three-step precipitation technics was optimized including the precipitant composition, precipitation temperature and pH value, etc. The research results showed that the optimal process for diffusion dialysis is: TWDDA3S anion exchange membrane from Shandong Tianwei Company was adopted, the feed flow was 6 ml/min (wastewater), and the flow ratio of the diffusion side to the dialysis side was 1.5:1. Under these conditions, the total recovery rate of nitric acid and hydrofluoric acid could reach up to 69.5%. Meanwhile, the retention rates of the three heavy metal ions including iron, chromium and nickel reached 97.0%, 98.0% and 96.4% respectively. The optimal process for the first-step precipitation is as follows: the mole concentration ratio of the composited precipitants of KOH and KF is 7:1, and the precipitation temperature is 15℃. Under these conditions, the recovery rates of heavy metals of iron and chromium reach 96.2% and 90.7% respectively. The optimal process for the second-step precipitation is as follows: 0.02mol/L HNO3 and 0.3mol/L KF are used to conduct advanced treatment on the filtrate from the first-step precipitation. Under these conditions, the retention rate and purity of nickel ions reach 98.7% and 89.6%, respectively. The optimal process for the third-step sedimentation is to control the pH of the filtrate at around 11 through KOH, under which all nickel can be recovered.

Key words: High-salinity unsymmetrical dimethyl wastewater, Diffusion dialysis, Three-step precipitation, Recovery of acids, Recovery of heavy metals

中图分类号: 

TrendMD: