Preparation of Coal Gangue-Desulfurization Gypsum-Fly Ash Paste Slurry and Its Properties
In order to ensure that the coal gangue paste composite filling slurry meets the requirements of mine pipeline transportation performance,coal gangue,desulfurization gypsum and fly ash were used to develop the paste composite filling material.Taking the fine gangue rate,coal gangue content and fly ash content as the research objects,the orthogonal test of three factors and four levels was carried out to explore the changing rules of slurry flow performance,workability and rheological properties.The Hershel-Bulkley model was used to fit the rheological parameters of coal gangue-based paste composite filling slurry.The correlation coefficient R2 is 0.999,and the model has high fitting accuracy and strong reliability.The research results show that the slump,diffusivity,fluidity,consistency and bleeding rate of slurry increase first and then decrease with the increase of fine gangue rate.When the fine gangue rate is 40％,the pumpability of slurry is the best.The coal gangue content has no significant effect on the pipeline transportation performance of slurry,but the kaolin phase in coal gangue will adsorb a small amount of free water,resulting in poor flow performance of slurry.Fly ash plays the role of ball lubrication and micro-aggregate in the paste slurry system,releasing a large amount of free water,thickening the water film on the surface of the particles,and improving the pipeline transportation performance of the slurry.However,when the fly ash content exceeds 35％,the agglomeration of fine particles of fly ash is serious,which enhances the ability of the slurry to resist shear deformation and weakens the flow performance and rheological properties of the slurry.
万方数据
维普
