Fabircation Of FGD Gypsum-steel Slag Composite Cementitious And Its New Type Block

Flue gas desulphurization (FGD) gypsum based steel slag is a new type of cementitiouscomposites materials with FGD gypsum as basal body and steel slag as fill body. The FGDgypsum-based steel slag composites show better performance and could raise the utilizationrate of these two kinds of industrial solid wastes. The FGD gypsum-based steel slag block isone of new types of wall materials, and it has environment protection, comfortableness, heatinsulation and higher intensity.This dissertation has done a systematic study and test of the material’s properties,production and application of hemihydrate gypsum-steel slag binder, according to thedemands of block’ industrial production and application. The reasonable technical parameterand performance has been improved by mechanical activation, activator, superplasticizermodification and curing style. Moreover, the research on the product’s testing has beencompleted through the mechanical properties, hardened crystal morphology.The mechanochemistry can activate the potential capability of the steel slag by crushingand grinding. The process and effect of mechanochemistry is the changes of the form, thestructure and the physical chemistry property for the solid matter. The particle size isdiminished speedily during the initial of the comminution by a series of analysis and testing,when they are ground for period of time, the apparent granularity become wide for theagglomeration between them, with the more prolong of the grinding time, the particle sizechanges hardly and reach the grinding balance. The cementitious performance of steel slagchanges with particle size. In the grinding, the component which has the worst grindabilityhas little hydrating activity. in contrary, the component which has the better grindability hasbetter hydrating activity.This dissertation selected cement clinker, additive lime and aluminum sulfate asactivators in order to activate the potential capability of the steel slag. The performance ofcementitious materials is mainly stimulated by single and combined admiture. The resultsshow that the compressive strength of composites cementious material with5%mass fractionof cement clinker, with3%mass fraction of slaked lime and with4%mass fraction of kaolinis11.8MPa，11.5MPa and11.3MPa respectively at the time of28days after mixing. The compressive strength of composites cementious material with3%cement clinker,2%slakedlime and4%aluminum sulfate is14.7MPa at the time of28days after mixing.The reasonable curing condition can not only provide enough water for steel slag andcement clinker to formed ettringite and cementitious material, but also damage skeleton madeFGD gypsum. Though comparing influence law under different curing methods. The resultshows that the compressive strength can reach14.7MPa at the time7days after mixing intemperature of75℃, relative humidity80%, time is6h.Appropriate amount of water reducer can enhance water-reducing rate, influent crystaland mechanical properties. The experimental results show that the compressive strength ofcomposites cementious material with1.2%mass fraction of polycarboxylate superplasticizer,with1.0%mass fraction of amino sulfonate is19.3MPa,12.8MPa at the time of7days aftermixing. The water-reducing effect of sika viscocrete is mainly achieved by electrostaticrepulsion effect and steric effect.Finally, the other contents studied of this paper is making new type block through theabove research results, according to the demands of gypsum block’s industrial production andapplication. The new type block is hollow, with tondue-and-groove,666×500×200mm and it’sperformance is detected.