Study on strength formation mechanism and microscopic properties of solidification of phosphogypsum with unsaturated polyester resin
Unsaturated polyester resin,methyl ethyl ketone peroxide curing agent,and cobalt isooctanoate accelerator(accelerator)were selected to stabilise and cure phosphogypsum.The effects of different dosa-ges of UPR and curing agent on the compressive strength of the solidified bodies at various ages were in-vestigated;the strength formation mechanism and microscopic morphology of the phosphogypsum csolidi-fied bodies were analysed by SEM and FTIR;and the leaching toxicity analysis of the phosphogypsum so-lidified body was carried out by ICP-MS.The study shows that:the compressive strength of phosphogyp-sum solidified bodies at all ages increases with the increase of UPR doping;with the increase of curing agent doping,the compressive strength of phosphogypsum solidified bodies shows a tendency of increasing firstly and then decreasing later;the compressive strength of phosphogypsum solidified bodies grows faster in the early stage and slower in the later stage.The optimal ratio of phosphogypsum solidified body is 100％phosphogypsum,40％UPR doping,0.8％curing agent doping,0.4％accelerator doping,and its 3,7,28 d compressive strength are 30.8,36.3,37.2 MPa,respectively.UPR fills up the pore space of phosphogypsum,tightly wraps around the phosphogypsum and binds with each other,and it solidifies rap-idly through the copolymerization reaction triggered by the curing agent and the activator,and generates the phosphogypsum solidified bodies.Through the copolymerisation reaction triggered by the curing agent and accelerator,it solidified rapidly,and the generated polymer three-dimensional crosslinked mesh struc-ture made the internal structure of the curing dense,forming an internal structure in which the ions could not be exchanged easily.The concentration of F-,PO43-and other heavy metal ions leached from the cured body of phosphogypsum meets the requirements of GB 8978-1996"Comprehensive Sewage Dis-charge Standard",Class Ⅰ discharge standard.
NETL
NSTL
万方数据
