A Study On The Cementation Material Based On The Water Quenching Slag For The Hard-solidified Tailings

In some mine of Anhui, as the special nature of tailings, the cementation effect ofnondescript cement and tailings is too poor to meet the mine production. It is urgent todevelop a new kind of material as the binder which is good effect and low-cost.Firstly, through a series of physical and chemical experiments, this thesis makesa study on the fundamental characteristics of the mine tailings to get some necessarybasic parameters. The very fine tailings with only83.25microns of average particlesize and the hard-solidified talc ingredients in the ore result the poor effect ofnondescript cement.In principle of convenient production and local materials, through on-the-spotinvestigation, this thesis selects the slag powder from a factory near the mine as themain ingredient of the binder and uses the proper activator to stimulate the slagactivity for the self-made slag cement. In order to evaluate the effect of activation andcementation on the slag and tailings directly, this thesis adopts the mortar experiment.The fixed slurry concentration is70%and the ratio of marl and sand is1to3.The experiment selects alkali activator and sulfate activator as the two materials.Through the experimental stimulation of single factor,bivariate composite and multi-orthogonal, the optimal formula for the binder is the combination of slag,clinker,solidwater glass and caustic soda in line with the ratio of1to0.3to0.12to0.02. Theexperimental results show that the self-made slag cement has a significant superiorityfor the mine tailings over the PC32.5cement and is lower cost.After getting the recipe of slag cement right, this thesis elaborates on thehydration mechanism of slag cement through the qualitative and micro analysis ofhydrated products from the self-made slag cementitious material by using the methodof SEM and DSC. The study on the cementation mechanism shows that the mainhydrated products of slag cementitious material are the amorphous hydrated calciumsilicate gel (C-S-H) and the platelike Ca(OH)2crystal. Ca(OH)2crystal formsgenerally in the previous period of hydration reaction and consums a lot in the lateuntil completely disappears. No ettringite and other crystals come into being.