Study On High Performance Composite Slag Powder

Slag powder is an important building material,mainly used for cement,concrete and mortar production.With the development of society,the development direction of the building is towards high rise and large span,the demand is growing for the building materials with high strength and high activity.With manganese slag and slag as main raw materials,the high-performance composite slag powder was prepared by the combined activation of physical and chemical method,realizing high-added value utilization for solid wastes.First,we used physical activation(grinding)method on the basis of physical and chemical analysis in order to improve the activity of manganese slag and slag.Four materials,glycerin,sodium stearate,tri-ethanolamine and tri-isopropanolamine,were screened from a number of grinding agents,and two special grinding agent HB-1 and HB-2 for slag and slag manganese respectively were further prepared from these materials.Based on the analysis of grinding mechanism,we prepared the grinding agent HB-3 using waste acid slag from a plasticizing agent factory,through a series of process as removal of methanol,neutralization and mix molding.This grinding aid is good for manganese slag and slag grinding.Compared with other grinding agents,this product has the outstanding advantage of lower cost,and can solve the problem of waste acid residue discharge for relevant manufacturer.In order to solve the problem of long test cycle for the 28d resist compression strength of mortar,we have established a rapid activation assessment method for blast-furnace granulated slag-manganese slag mix powder,which will shorten the experimental period to 24 hours.To be exactly,curing 4h at room temperature first and then steam curing 24h at 60?.Least square method was used to fit the experimental data,and the relationship was obtained:R??28d=0.82R??+28.23.The correlation coefficient of model and actual data is 0.99.The effects of the fineness and the ratio of slag and manganese slag on the composite powder were studied.The results showed that the optimal specific surface area of slag and slag manganese is 519m2 / kg and 563m2 / kg respectively,the optimal mass ratio of slag and slag manganese is 7:3.The composite activator(silicate 4%,anhydrous gypsum 3%,sodium cit-rate 0.03%)was developed for the manganese slag and slag in order to further improve the activity.Thus high performance composite slag was prepared which can reach Grade S105,according to GBT12957-2005(The test method for activity of industrial waste slag used as addition to cement).In order to investigate hydration reaction mechanism of the system,X-ray diffraction(XRD)and scanning electron microscopy(SEM)were used.The main products of the hydration reaction of gelled material is entringite,C-S-H,C-A-H and some amorphous gel.The hydration process of the system experienced roughly three stages: the dissociation(1)of slag and manganese slag;hydration reaction;and aggregation of hydration(2)(3)reaction products and the material that's not involved in the reaction.