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 (3): 86-90.doi: 10.19964/j.issn.1006-4990.2023-0184

• 研究与开发 • 上一篇    下一篇

氟硅酸制备高纯氟化铝新工艺研究

王建萍(), 薛旭金(), 薛峰峰   

  1. 多氟多新材料股份有限公司,河南 焦作 454191
  • 收稿日期:2023-03-31 出版日期:2024-03-10 发布日期:2024-03-14
  • 通讯作者: 薛旭金(1973— ),男,正高级工程师,从事新材料、新工艺研究;E-mail:dfdzcb@dfdchem.com
  • 作者简介:王建萍(1973— ),女,高级工程师,从事新材料、新工艺研究;E-mail:dfdzcb@dfdchem.com

Study on new process of preparing high-purity aluminium fluoride from fluorosilicic acid

WANG Jianping(), XUE Xujin(), XUE Fengfeng   

  1. Do-Fluoride New Materials Co.,Ltd.,Jiaozuo 454191,China
  • Received:2023-03-31 Published:2024-03-10 Online:2024-03-14

摘要:

面对中国战略资源萤石日益匮乏的现状,开发了以磷肥副产氟硅酸为原料合成氟硅酸钠,经动态分解得到四氟化硅,四氟化硅纯化后和无水氯化铝发生气相沉积反应、提纯制备高纯氟化铝工艺路线,并对反应原理、工艺流程、关键点控制及产品质量和原料成本等进行研究。结果表明:氟硅酸钠软膏采用两级干燥方式进行干燥,干燥后水分≤0.05%(质量分数);氟硅酸钠热解采用动态分解方式,分解率>99%。粗四氟化硅气体采用浓硫酸洗涤、分子筛吸附、精馏提纯后纯度>99.5%;无水氯化铝以气体状态和提纯的四氟化硅反应,反应后产品纯度>99.5%,符合高端领域市场需求。该研究可为磷肥副产低品位氟资源的高效高值利用提供参考和借鉴。

关键词: 氟硅酸, 氟硅酸钠, 气相沉积, 高纯氟化铝

Abstract:

Faced with the increasing shortage of fluorspar,a strategic resource in China,an industrial route for preparation of high-purity aluminium fluoride from fluorosilicic acid,a by-product of phosphate fertilizer was developed.Fluorosilicic acid was used as raw material to synthesize sodium fluorosilicate,which was further dynamically decomposed to get silicon tetrafluoride.Silicon tetrafluoride was purified and then reacted with anhydrous aluminium chloride in vapour phase deposition to prepare high-purity aluminium fluoride.The reaction principle,process flow,key point control,product quality and raw material cost were also studied.The results showed that sodium fluorosilicate paste was dried by two-stage drying method,and the moisture content after drying was ≤0.05%(mass fraction).Dynamic decomposition method was adopted for sodium fluorosilicate pyrolysis with decomposition rate >99%.The purity of crude silicon tetrafluoride gas after washing with concentrated sulfuric acid,molecular sieve adsorption and distilled purification could reach 99.5%.Aluminium chloride reacted with purified silicon tetrafluoride in gas state,and the purity of the product after reaction was >99.5%,which met the market demand in high-end field.This study could provide reference and guidance for the efficient and high-value utilization of low grade fluoride resources as by-product of phosphate fertilizer.

Key words: fluorosilicic acid, sodium fluorosilicate, vapor deposition, high purity aluminium fluoride

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