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 (2): 86-94.doi: 10.19964/j.issn.1006-4990.2023-0203

• 环境·健康·安全 • 上一篇    下一篇

磷石膏配料碳热熔融还原硫逸出及熔渣物相分析

王艳语1(), 谷守玉1, 侯翠红1(), 井红权1, 关红玲1, 张晖2   

  1. 1.郑州大学化工学院, 国家钙镁磷复合肥技术研究推广中心, 河南 郑州 450001
    2.云南云天化环保科技有限公司, 云南 昆明 650000
  • 收稿日期:2023-04-10 出版日期:2024-02-10 发布日期:2024-02-06
  • 通讯作者: 侯翠红(1970— ),教授,博士生导师,主要研究方向为绿色智能肥料和磷资源高效利用;E-mail:hch92@zzu.edu.cn
  • 作者简介:王艳语(1984— ),女,博士研究生,研究方向为磷化工绿色加工与固废资源化利用;E-mail:wangyanyu360825@126.com
  • 基金资助:
    “十三五”国家重点研发计划项目(2018YFC1900201-01)

Sulfur escape and slag physical phase analysis by carbon thermal reduction melting based on phosphogypsum ingredients

WANG Yanyu1(), GU Shouyu1, HOU Cuihong1(), JING Hongquan1, GUAN Hongling1, ZHANG Hui2   

  1. 1.School of Chemical Engineering,Zhengzhou University,National Research & Popularization Center for;Calcium,Magnesium,Phosphate and Compound Fertilizer,Zhengzhou 450001,China
    2.Yunnan Yuntianhua;Environmental Protection Technology Co. ,Ltd. ,Kunming 650000,China
  • Received:2023-04-10 Published:2024-02-10 Online:2024-02-06

摘要:

基于配料计算在磷石膏中添加硅、铝、镁等,使其渣系满足矿渣棉生产对酸度系数、氢离子指数、黏度系数的要求。通过热重分析、熔融特性的测定及高温还原焙烧/熔融实验,探究了磷石膏配料在高温还原过程中硫逸出及熔渣的物相结构。结果表明:碳的加入可以促进磷石膏分解,加入量以n(C)/n(S)=0.5为宜;还原剂(石墨、无烟煤、焦炭)及配料的加入均可以降低磷石膏体系的熔融特征温度,CaO-MgO-SiO2-Al2O3四元相图计算表明配料体系在1 255.73 ℃时形成最低共熔点。磷石膏及其配料在高温焙烧过程中的物相演变规律表明,CaS为CaSO4还原过程的中间产物,配料中加入的SiO2可结合更多的CaO促进CaS和CaSO4反应的进行。还原熔融实验表明,n(C)/n(S)对熔渣硫含量及体系脱硫率影响较大。以焦炭为还原剂,磷石膏配料的酸度系数Mk=1.4、pH=4.85、n(C)/n(S)为0.5时,采用刚玉坩埚在1 450 ℃下高温熔融20 min后,脱硫率可达99.05%,硫高效逸出的同时形成的熔渣呈非晶态,具有良好的玻璃相结构。

关键词: 磷石膏配料, 热分析, 脱硫率, 物相演变

Abstract:

Silicon,aluminum,and magnesium oxides et al.were added to phosphogypsum based on batching calculations to meet the requirements of acidity coefficient,hydrogen ion index and viscosity coefficient for slag wool production.The sulfur escape from phosphogypsum ingredients and the physical phase structure of slags were investigated by thermogravimetric analysis,determination of melting characteristics,and high-temperature reduction roasting and melting experiments.The results showed that the addition of carbon could promote the decomposition of phosphogypsum,and the n(C)/n(S)of 0.5 was favorable to the desulfurization of the system.The reducing agents(graphite,anthracite,coke) and ingredients could decrease the characteristic melting temperatures of phosphogypsum.The CaO-MgO-SiO2-Al2O3 quaternary phase diagram showed that the ingredient system formed the lowest eutectic point at 1 255.73 ℃.The phase evolution of phosphogypsum and its ingredients during high-temperature roasting illustrated that CaS was the intermediate product of CaSO4 reduction process,and the SiO2 in the ingredients combined with more CaO to promote the reaction between CaS and CaSO4.The high-temperature reduction melting experiments showed that the amount of carbon had a significant impact on the sulfur content of slag and the desulfurization rate of the system.The phosphogypsum ingredients with Mk=1.4,pH of 4.85,and n(C)/n(S) of 0.5 with coke as a reducing agent were melted in the corundum crucible at 1 450 ℃ for 20 min,the desulfurization rate could reach 99.05%,while the slag formed was amorphous with a good glass phase structure.

Key words: phosphogypsum ingredients, thermal analysis, desulfurization rate, phase evolution

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