Inorganic Chemicals Industry ›› 2023, Vol. 55 ›› Issue (12): 102-110.doi: 10.19964/j.issn.1006-4990.2023-0138

• Environment·Health·Safety • Previous Articles     Next Articles

Study on preparation and modification of phosphogypsum-based architectural gypsum

GUO Shuang1(), XING Dongxian1, GUO Xiao1, JI Xiaojie1, TANG Jianwei2, HUA Quanxian1, WANG Baoming2, LIU Yong1()   

  1. 1. School of Chemical Engineering,Zhengzhou University,Zhengzhou 450001,China
    2. School of Ecology and Environment,Zhengzhou University,Zhengzhou 450001,China
  • Received:2023-03-14 Online:2023-12-10 Published:2023-12-14
  • Contact: LIU Yong E-mail:1345428310@qq.com;yongliu@zzu.edu.cn

Abstract:

Using phosphogypsum as raw material,the impurities in phosphogypsum were removed by water washing method,architectural gypsum was prepared by low-temperature calcination,and the effects of calcination temperature and calcination time on gypsum strength and three-phase component content were studied with the help of DSC-TG technology,and then the effects of additives such as sodium tripolyphosphate,fly ash reinforcing agent,melamine and polypropylene fiber of retarder were investigated on the physical and chemical properties of gypsum test block.The results showed that the mass fraction of β-CaSO4·0.5H2O prepared under the condition of low calcination at 170 ℃ and 3 h was 72.23%,and the mechanical properties of gypsum test block were better than those of grade 2.0 products in GB/T 9776—2008“Building Gypsum”The sodium tripolyphosphate with an added amount of 0.15%(mass fraction,the same below) was used as a retarder,and fly ash with an added amount of 5.00% was used as a reinforcing agent with an addition amount of 0.05% melamine was used as a water reducing agent and polypropylene fiber with an addition of 1.00% was modified to build gypsum powder,and the dry flexural strength and dry compressive strength of the prepared gypsum test block were 4.17 MPa and 12.97 MPa for 7 d.The role of various additives in the preparation of architectural gypsum powder using phosphogypsum as raw material was discussed,and the construction gypsum powder with good performance was prepared,which provided technical methods and theoretical basis for the comprehensive utilization of phosphogypsum.

Key words: phosphogypsum, gypsum hemihydrate, strength, construction plaster, low calcination

CLC Number: