无机盐工业
主管:中海油天津化工研究设计院有限公司
主办:中海油天津化工研究设计院有限公司
   中海油炼油化工科学研究院(北京)有限公司
   中国化工学会无机酸碱盐专业委员会
ISSN 1006-4990 CN 12-1069/TQ

无机盐工业 ›› 2024, Vol. 56 ›› Issue (10): 95-102.doi: 10.19964/j.issn.1006-4990.2024-0128

• 环境·健康·安全 • 上一篇    下一篇

热解法脱除工业废盐中总有机碳的工艺研究

李鸿源1,2(), 张建华1,2()   

  1. 1.江南大学工业生物技术教育部重点实验室,江苏 无锡 214122
    2.江南大学生物工程学院,江苏 无锡 214122
  • 收稿日期:2024-03-05 出版日期:2024-10-10 发布日期:2024-11-05
  • 通讯作者: 张建华(1969— ),男,博士,研究员,研究方向为生物产物分离与清洁生产;E-mail:jhzh882@163.com
  • 作者简介:李鸿源(1998— ),男,硕士,研究方向为生物产物分离与清洁生产;E-mail:1015778146@qq.com
  • 基金资助:
    国家重点研发计划项目(2021YFC2102204-02)

Study on removal process of total organic carbon from industrial waste salts by pyrolysis

LI Hongyuan1,2(), ZHANG Jianhua1,2()   

  1. 1.Key Laboratory of Industrial Biotechnology Ministry of Education,Jiangnan University,Wuxi 214122,China
    2.School of Biotechnology,Jiangnan University,Wuxi 214122,China
  • Received:2024-03-05 Published:2024-10-10 Online:2024-11-05

摘要:

高效率、低成本地脱除废盐中的总有机碳(TOC),是实现废盐资源化途径中重要的预处理手段。以两种代表性工业废盐(简称高氯化钠、高硫酸钠)为对象开展高温热解工艺研究,结果表明:高氯化钠在350 ℃、堆积厚度为12.5 mm条件下热解60 min,TOC去除率为94%;高硫酸钠在450 ℃、堆积厚度为18.5 mm条件下热解40 min,TOC去除率为94.2%。热解前向高氯化钠中添加7.5 mL/kg双氧水,250 ℃热解时的TOC去除率和350 ℃不添加双氧水的去除率相当,向高硫酸钠中添加10 mL/kg双氧水后,350 ℃热解的TOC去除率和450 ℃不添加双氧水的去除率相当,即采用双氧水氧化协同热解后两种废盐的热解温度均降低了100 ℃,节能效果显著。开展了分步结晶实验并对回收的盐分进行检测,结果表明,在回收率为90%的条件下,回收的氯化钠、硫酸钠的TOC含量分别为22.7 mg/kg和26.5 mg/kg,氯化钠纯度为93.2%,满足国家工业盐标准中日晒工业盐二级标准,硫酸钠纯度为93.0%,满足国家工业无水硫酸钠标准中Ⅲ类合格品标准。

关键词: 废盐, 高氯化钠, 高硫酸钠, 热解, 总有机碳, 结晶

Abstract:

Highly efficient and low⁃cost removal of total organic carbon(TOC) from waste salt is an important pretreatment method in achieving salt resource utilization.This study focused on the high⁃temperature pyrolysis process of two representative industrial waste salts(sodium chloride and sodium sulfate).The results showed that under the condition of 350 ℃ and a stacking thickness of 12.5 mm,sodium chloride underwent pyrolysis for 60 min,the TOC removal rate was 94%.Under the condition of 450 ℃ and a stacking thickness of 18.5 mm,the pyrolysis time of high sodium sulfate was 40 min,the TOC removal rate was 94.2%.Before pyrolysis,7.5 mL/kg hydrogen peroxide was added to high sodium chloride.The TOC removal rate during 250 ℃ pyrolysis was comparable to that at 350 ℃ without hydrogen peroxide.After adding 10 mL/kg hydrogen peroxide to high sodium sulfate,the TOC removal rate during 350 ℃ pyrolysis was comparable to that at 450 ℃ without hydrogen peroxide.The pyrolysis temperature of both waste salts was reduced by 100 ℃ after using advanced oxidation synergistic pyrolysis,and the energy⁃saving effect was significant.A stepwise crystallization experiment was conducted and the recovered salt was tested.The results showed that under the condition of a recovery rate of 90%,the TOC content of the recovered sodium chloride and sodium sulfate were 22.7 mg/kg and 26.5 mg/kg,respectively.The purity of sodium chloride was 93.2%,which met the secondary standard of sun industrial salt in the national industrial salt standard.Sodium sulfate had a purity of 93.0% and met the Class Ⅲ qualified products standard in the national industrial anhydrous sodium sulfate standard.

Key words: waste salt, sodium chloride, sodium sulfate, pyrolysis, total organic carbon, crystallization

中图分类号: