Research On The Utilisation Of Waste Residue Wet Grinding And Shelling And Regeneration Gelling In Mixing Station

The waste residue of the mixing station is an inevitable waste for the production and operation of the commercial concrete mixing station.The waste residue of the mixing station loses its gelling capacity,has greater water absorption,high recycling cost and low product value.For the mixing station,the treatment of waste residue is a traditional problem.In response to this problem,this thesis proposes a method for the recycling of waste residue wet grinding and shelling gelling in the mixing station.Using the evaluation method of the working performance and mechanical performance of cement slurry,the influence of waste residue on slurry physical performance and working performance after wet grinding regeneration gelling treatment is explored.Through advanced testing methods such as hydration heat analysis,XRD,SEM,etc.,the slag after wet grinding regeneration gelling treatment on cement-based materials is analysed.Hardening mechanism.To this end,this article has done exploratory and innovative research in the following aspects:（1）Regenerative gelling characterisation of waste residue wet grinding and shelling in mixing stationBy testing the physical and chemical properties of the waste residue of the mixing station,it provides a theoretical basis for the use of the waste residue of the mixing station as a mineral admixture.By means of particle size distribution analysis and SEM,the particle size distribution and microscopic morphology of the waste residue after wet grinding shelling are analysed and observed,so as to characterise the Condensation effect.The results show that the main mineral components of the waste residue of the mixing station are C₃S,C₂S,C₃A,C₄AF,C-S-H and Ca（OH）₂,and the proportion of gelling components in the chemical composition is extremely large.The waste residue of the mixing station is treated by wet grinding and shelling,breaking the adhesion between Many hydration product particles with extremely fine particle size have been produced,and brand-new cement particles have been obtained,thus restoring the hydration activity,and cementing performance,and realising the gelling regeneration of waste residue.（2）Research on the development mechanism of the strength of the slurry by the regeneration gel of waste residue in the mixing stationBy changing the ageing time of waste residue,the time of waste residue wet grinding regeneration gelling time and the amount of wet grinding recycled waste residue,the influence of wet grinding regeneration gel on the compressive strength of waste residue glue sand specimen is determined.The research results show that with the increase of ageing time,the compressive strength of the waste slag slurry continues to decrease.The compressive strength of the waste slag slurry after wet grinding is increased first and then reduced.The ageing time of waste residue should not be too long.It is more appropriate between 14-18 hours,and the ageing time reaches 16 hours and then The compressive strength of the waste slurry reaches the maximum;with the increase of wet grinding time,the compressive strength of the slurry increases first and then tends to stabilise.Considering the efficiency of wet grinding,it is advisable to choose wet grinding recycled gel for 10min;with the increase of wet grinding waste residue,When the content of wet grinding regenerated cementitious waste slag is 50%,the compressive strength of the slurry reaches a maximum of 53.71 MPa.（3）Research on microscopic morphology and hydration characteristics of wet-milled recycled cement-based materialsThrough cement hydration heat,XRD,SEM and other micro-testing techniques,the effect of wet grinding regeneration gelling on the early hydration of the slurry was studied,and the XRD technology was used to determine the effect on the crystalline phase in the slurry.Finally,the change of micro-morphology was observed by SEM.The results showed that the early heat release rate of the slurry was increased under wet grinding regeneration gelling is relatively fast,the crystal phase content of Ca（OH）2 is relatively high,and the morphology of the pulp is more dense after hardening.This is due to the’crystal nucleation’of nano-scale hydration product particles in the wet grinding of the waste The early hydration reaction rate of the waste slurry is accelerated.At the same time,the filling effect of particles optimizes the pore structure inside the slurry and strengthens the strength of the late slurry.（4）Study on the impact of waste residue on the working performance of the slurry in the wet grinding mixing stationThe slurry was prepared by changing the aging time of waste residue,the gelling time of wet grinding regeneration of waste residue,and the amount of wet grinding regeneration waste residue.A suitable rheological model was established to determine its flow and rheological properties.The results showed that with the increase of the aging time of the waste residue,the wet grinding regenerated waste residue gelled for10 minutes can better improve the fluidity of the slurry;The rheological curve changes of the slurry under wet grinding conform to Bingham’s model,and the rheological parameters of the waste slag slurry after 10 min of wet grinding and regeneration cementation,such as shear stress.With the continuous increase in the amount of wet grinding regenerated cementitious waste residue,both the fluidity of the slurry and the rheological parameters of the slurry continue to increase.To ensure the working performance of the slurry,the amount of wet grinding waste residue should not exceed 40%.Through wet grinding and regeneration gelling treatment,the impact of ball milling beads is used to agglomerate waste residue particles,which causes the hydration products on the surface of the waste residue to be peeled off,and the solid phase volume fraction of the waste residue particles is reduced.This also allows the release of water molecules between the hydration products,enhancing the working performance of the slurry.However,as the aging time of the waste residue in the mixing station becomes longer,the hydration products increase and the protective shell becomes thicker.Although free water molecules that are flocculated by the waste residue can be released through wet grinding and regeneration gelling treatment,too many nano scale hydration product particles are produced by wet grinding,which are filled in the entire slurry.Adding finer particles to the slurry will cause an increase in the water consumption for standard consistency,resulting in a decrease in the working performance of the slurry.