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): 103-109.doi: 10.19964/j.issn.1006-4990.2024-0119

• 环境·健康·安全 • 上一篇    下一篇

磷石膏草酸预处理滤液在取向硅钢涂料中的应用研究

向凌辉1(), 伍林1,2, 刘盈2,3, 胡雅1,2()   

  1. 1.武汉科技大学化学与化工学院,湖北 武汉 430081
    2.武汉科技大学绿色制造工程研究院,湖北 武汉 430081
    3.武汉科技大学资源与环境工程学院,湖北 武汉 430081
  • 收稿日期:2024-03-04 出版日期:2024-10-10 发布日期:2024-11-05
  • 通讯作者: 胡雅(1986— ),女,博士,副教授,研究方向为节能减排与环境友好化工技术开发与应用;E-mail:huya@wust.wust.edu.cn
  • 作者简介:向凌辉(1999— ),男,硕士研究生,研究方向为磷石膏高价值利用;E-mail:xianglinghui@wust.edu.cn
  • 基金资助:
    湖北省重点研发计划项目(2020BAB084)

Study on application of phosphogypsum oxalic acid pretreatment liquid in oriented silicon steel coatings

XIANG Linghui1(), WU Lin1,2, LIU Ying2,3, HU Ya1,2()   

  1. 1.School of Chemistry and Chemical Engineering, Wuhan University of Science and Technology, Wuhan 430081, China
    2.Academy of Green Manufacturing Engineering, Wuhan University of Science and Technology, Wuhan 430081, China
    3.College of Resource and Environmental Engineering, Wuhan University of Science and Technology, Wuhan 430081, China
  • Received:2024-03-04 Published:2024-10-10 Online:2024-11-05

摘要:

磷石膏高值化利用必须要进行预处理,其中水洗预处理产生的滤液还未有良好的利用途径。通过成分分析发现滤液中含有磷酸盐类、铝类等成分,是提升涂层防腐蚀性能的有效组分。将磷石膏预处理滤液加入到取向硅钢用无机无铬防腐涂料中,并对比了水与草酸溶液不同温度预处理后产生的滤液对涂层防腐性能的影响,研究了滤液中存在的物质及其对涂层防腐蚀性能的提升机理。在草酸溶液预处理、预处理温度为20 ℃及预处理滤液加入量为5%(质量分数)的条件下,取向硅钢片涂层中性盐雾实验由36 h腐蚀面积为11%降低至腐蚀面积小于1%,腐蚀电流密度降低至0.317 1 μA/cm2,涂层总体阻抗模值提升17%。草酸与磷类杂质反应生成的正磷酸盐占滤液中总磷类的95%以上,滤液通过促进AlPO4网络深度交联形成涂层主体网络结构、突出MgO的作用在高温下生成Mg3(PO42网络支链、生成微晶Mg2P2O7和AlF3填充网络孔隙,共同提升了涂层的防腐蚀性。

关键词: 磷石膏, 草酸, 取向硅钢, 涂层, 磷酸盐网络

Abstract:

Pretreatment is necessary for high value utilization of phosphogypsum,and the filtrate produced by water washing pre⁃treatment has not yet been well utilized.After component analysis,it was found that the filtrate contained components such as phosphates and aluminum,which were effective components for improving the corrosion resistance of coatings.The present study involved the preparation of phosphogypsum pretreatment filtrate and its incorporation into an inorganic chromium⁃free anti⁃corrosion coating for oriented silicon steel.A comparative analysis was conducted to evaluate the impact of pretreatment filtrate generated using water and oxalic acid solution at different temperatures on the corrosion resistance properties of the coating,and the substances present in the filtrate and their improvement mechanism on the anti⁃corrosion performance of the coatings were studied.Under the pretreatment of oxalic acid solution,pretreatment temperature of 20 ℃,and the addition of 5% pretreatment solution,the neutral salt spray experiment of oriented silicon steel sheet coating was decreased from 11% corrosion area after 36 hours to less than 1% corrosion area,and the corrosion current density was decreased to 0.317 1 μA/cm2,overall impedance modulus of coating was increased by 17%.The orthophosphate generated by the reaction between oxalic acid and phosphorus impurities accounted for more than 95% of the total phosphorus in the filtrate.The filtrate promoted deep cross⁃linking of the AlPO4 network to form the main network structure of the coating,highlights the role of MgO,and generated Mg3(PO42 network branches at high temperatures,forming microcrystalline Mg2P2O7 and AlF3 to fill the network pores,jointly improving the corrosion resistance of the coating.

Key words: phosphogypsum, oxalic acid, oriented silicon steel, coating, phosphate network

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