磷石膏基粘结石膏的制备及影响因素研究

Study on the preparation and influencing factors of phosphogypsum-based gypsum binders

研究三聚磷酸钠、纤维素醚、PVA对磷建筑石膏凝结时间和强度的影响,优化粘结石膏配比。结果表明:三聚磷酸钠缓凝效果较优,但掺量太多导致强度明显降低;纤维素醚和PVA能够明显提高石膏的拉伸粘结强度,但不利于抗折、抗压强度发展;α-HH掺入使石膏强度明显提高,且凝结时间明显延长。最优配比为磷建筑石膏与α高强石膏质量比为1∶1,聚磷酸钠、HPMC、PVA掺量分别为石膏质量的0.3%、0.1%、0.2%,此时粘结石膏的抗折、抗压、拉伸粘结强度分别为5.1、18.8、1.3 MPa。

The effects of sodium tripolyphosphate,cellulose ether,and PVA on the setting time and strength of phosphorus building gypsum were studied to optimize the proportion of gypsum binders.The results show that the sodium tripolyphosphate has excellent retarding effect,but too much of it leads to obvious loss of strength;cellulose ether and PVA can obviously improve the tensile strength of gypsum,but not conducive to the development of flexural and compressive strength;the addition ofα-HH can significantly improve the strength of gypsum and prolong the setting time of gypsum.The optimal ratio is that the mass ratio of phosphorous building gypsum toαhigh-strength gypsum is 1∶1,and the content of sodium polyphosphate,HPMC,and PVA are 0.3%,0.1%,and 0.2%of the mass of gypsum,respectively.Flexural strength,compressive strength and tensile bond strength are 5.1,18.8,1.3 MPa,respectively.