Inorganic Chemicals Industry ›› 2025, Vol. 57 ›› Issue (4): 89-96.doi: 10.19964/j.issn.1006-4990.2024-0287

• Environment·Health·Safety • Previous Articles     Next Articles

Study on mechanical properties of high content modified hemihydrate phosphogypsum wall materials

LONG Qijun1,2(), WU Qin1(), TAO Jia2, CHEN Chuanxiang1, WANG Jianxiang1, YU Fang1   

  1. 1. School of Civil Engineering and Architecture,Guizhou Minzu University,Guiyang 550025,China
    2. MaterialsIndustrial Co.,Ltd. of the Fifth Bureau(Group) Corporation of China Railway,Changsha 410000,China
  • Received:2024-05-23 Online:2025-04-10 Published:2024-08-01
  • Contact: WU Qin E-mail:lqjnwsuaf@163.com;wuqin0508@163.com

Abstract:

In order to improve the resource utilization rate of phosphogypsum,the modified hemihydrate phosphogypsum wall materials(MPGWM) was prepared by adding quicklime and melamine water reducing agent(SM) to hemihydrate phosphogypsum(HPG).The control variable method was used to study the effect of water-cement ratio and water reducing agent content on the mechanical properties of MPGWM,combined with the multiple regression model to analyze the variation rule of the mechanical properties of MPGWM under the action of two-factor coupling,and to obtain the optimal ratio of the high content modified hemihydrate phosphogypsum wall materials.The results showed that the main failure characteristics of the cubic compressive strength test of high content MPGWM specimens were splitting failure and conical failure,and the failure pattern of the cubic splitting tensile test was typical splitting failure.The apparent density of the specimens was mainly derived from HPG and quicklime.The apparent density and mechanical properties of MPGWM specimens were greatly affected by water-cement ratio,followed by the amount of water reducing agent.When the content of SM was 1.0% and the water-cement mass ratio was 0.29,the cube compressive strength of the specimens could reach 27.87 MPa.When the content of SM was 1.0% and the water-cement mass ratio was 0.32,the splitting tensile strength could reach 1.92 MPa.Through regression analysis,the optimal mix ratio of MPGWM was predicted to be 97%(mass fraction) HPG,3% quicklime,water-cement mass ratio of 0.27,and water reducer dosage of 1.2% of the HPG and quicklime mixture.The research results could provide reference for the resource utilization of phosphogypsum and promote the sustainable development of phosphorus chemical enterprises.

Key words: hemihydrate phosphogypsum, collaborative modification, water reducing agent, mechanical properties

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