Isocyanate contains rich-NCO group,which can react with water,and the benzene ring in isocyanate belongs to the hydrophobic group,which can provide the material with hydrophobic properties.As a modifier,isocya-nate is used to modify phosphogypsum,so as to improve the performance of phosphogypsum.In this paper,the effect of isocyanate content on the mechanical properties,the softening coefficient,and the leaching efficiency of phosphate radical and fluoride ions of the phosphogypsum specimen were studied.The results showed that when the isocyanate content was 0.8％and the water consumption was 70％,the indexes of the phosphogypsum specimen obtained were as follows:flexural strength 2.5 MPa,compressive strength 6.70 MPa,softening coefficient 0.87,fluoride ion con-centration 4.73 mg/L,phosphate radical concentration 11.49 mg/L.Compared with that without isocyanate,the flexural strength of the modified phosphogypsum specimen increased by 23.15％,the compressive strength increased by 73.13％,the softening coefficient increased by 89.13％,the fluoride ion concentration in the leaching solution decreased by 58.91％,and the phosphate radical concentration decreased by 69.87％.
万方数据
维普
