XUE J, WANG X Y, WU J, et al． Application research of phosphogypsum based anhydrous calcium sulfate as PVC filler [J]. Journal of Henan Polytechnic University( Natural Science) ， doi: 10.16186/j.cnki.1673-9787.（ 2024030070）..

doi: 10.16186/j.cnki.1673-9787. （ 2024030070）..

Received： 2024-03-26

Revised： 2024-05-06

Online： 2026-06-04

Application research of phosphogypsum based anhydrous calcium sulfate as PVC filler (Online)

Xue Jun1, Wang Xunyan1, Wu Jing2, Lin Zhigao3, Liu Fangjun1, Li Lei1, Ma Huijuan 4, Jiang Jizhou1

1.School of Materials Science and Engineering, School of Environmental Ecology and Biological Engineering, Novel Catalytic Materials of Hubei Engineering Research Center, Engineering Research Center of Phosphorus Resources Development and Utilization of Ministry of Education, Wuhan 430205, Hubei, China; 2.Key Laboratory of Rare Mineral, Ministry of Natural Resources, Geological Experimental Testing Center of Hubei Province, Wuhan, 430034, Hubei, China; 3. Hubei Jinniu Pipe Industry Co., Ltd, Wuhan, 430050, Hubei, China；4.Hubei Three Gorges Laboratory, Yichang, 443000, Hubei, China

Abstract: Objectives To study the feasibility of using phosphogypsum based anhydrous calcium sulfate (P-AH) as a PVC resin filler, in order to solve the "three phosphorus" problem led by phosphogypsum and achieve the resource utilization of solid waste. Methods Using heavy calcium carbonate (HCC) as the comparative object, PVC composite materials were made according to the same formula. By comparing the impact strength, bending strength, bending modulus, thermal conductivity, and thermal weight loss of the composite materials, and conducting SEM tests on the impact fracture surface of the samples, the feasibility of using P-AH as a filler was explored. On this basis, actual production will be carried out through productive experiments. Results For PVC/P-AH composites, with the increase of dosage, the impact strength does not change much, the flexural strength and flexural modulus increase exponentially, while the thermal conductivity increases linearly. When the filler fraction is 35 parts, the impact strength is 9.9 MPa, the flexural strength is 64.5 MPa, the flexural modulus is 3878 MPa, and the thermal conductivity is 0.252 W(m·K)-1. At high dosage, except for the flexural modulus, the performance of PVC/HCC composites is weaker than that of PVC/P-AH composites; Through SEM testing of the cross-section, it was found that PVC/HCC composites exhibit powder agglomeration, which is the direct reason for their lower strength. However, through DSC-TG testing analysis, it was found that during PVC decomposition, PVC/P-AH composites need to absorb 157.13 J/g of energy, while PVC/HCC composites need to absorb 138.95 J/g of energy. The former is less prone to decomposition. By using P-AH in the actual production of PVC pipes, qualified products were obtained, and except for color, other performance indicators were slightly better than traditional heavy calcium fillers. Conclusions P-AH can be directly used as PVC resin filler, thus expanding a new high-value path for the application of phosphogypsum.

Key words: Phosphogypsum; Anhydrous calcium sulfate; Filler; PVC resin