The Preparation And Performance Reseach Of Self-igniting Gangue-slag-fly Ash Geopolymer

The main part of gangue is alumino silicate minerals and carbon.It had a quality of rich insilica and alumina and quantity of bulk which decided that the quality and quantity of gangueand building materials had double approximation and the feasibility of the gangue’s resourceutilization in the cement field. This article is a subproject of a National Natural ScienceFoundation joint projec《tThe research of key scientific problems about the resource utilization ofgangue in cement and concrete resource》(U1261122).All the research is completed and achievedunder the the Fund.In this paper,as the spontaneous combustion coal gangue,fly ash and slag playing a role ofthe main raw material, we appropriately prepared geopolymer under the action of alkalineactivator.First we used orthogonal experiment and investigated the effect of three factors ongeopolymer mortar strength.They are the dosage of spontaneous combustion gangue ash, flyash and elicitor water glass. By analyzing the the poor and variance of the results of orthogonaltest analysis,optimizing the mix parameters. On this basis,we examed the cementitiousmaterials of theoptimal fit and other main technical performance, including fineness, time ofcoagulation,stability of volume,hydration heat and ect.The main research results are as follows:(1)Under the water binder ratio of0.46of spontaneous combustion gangue-slag-fly ashgeopolymer and after stripping the specimen was steam curing for6h in65℃environment,thespecimens which is molded with the optimum mixture ratio(spontaneous combustion gangue:slag: fly ash=2:1:1, inspire ligand sodium metasilicate: potassium hydroxide=7:3,andelicitor dosage is10.5%)will have the flexural strength of Mortar of3d and28d with5.3Mpaand7.2Mpa, the compressive strength with37.9Mpa and42.73Mpa. This meet the requirementsof portland cement42.5strength grade.(2)To the spontaneous combustion gangue-slag-fly ash geopolymer, the order of theeffective degree on the mortar strength of the factors is the content of coal gangue, followed byslag(or fly ash) and the sodium metasilicate.(3)The concentration of alkali in the composite excitation ligand must be moderate. With ahigh concentration of alkali, it could not only cause a increased cost of spontaneous combustiongangue-slag-fly ash geopolymer, but a strength retraction phenomenon of the mortar flexuralstrength and compressive strength with the age prolongation. It needs to pay more attention. (4)The fitness、setting time、stability of volume and other technical performance indicatorsof the spontaneous combustion gangue-slag-fly ash geopolymer meet the national standard ofGB175-1999, and it has the technical characteristics that the final setting time is relatively short.