Method for preparing cementing material by sintering activation of coal gangue

A method for preparing a cementitious material by a sintering activation of a coal gangue, comprising following steps:

• (1) a pretreatment:
• crushing a coarse-grained coal gangue to a predetermined particle size to obtain a crushed coal gangue;
• (2) batching, mixing and granulating:
• fully mixing the crushed coal gangue obtained in step (1), a composite additive, and water according to a set proportion to obtain a first resulting mixture and granulating the first resulting mixture to obtain granulated pellets;
• (3) a sintering activation:
• distributing, igniting and exhausting the granulated pellets obtained in step (2) in a sintering machine for the sintering activation to obtain a decarburized coal gangue sinter;
• (4) cooling:
• cooling the decarburized coal gangue sinter obtained in step (3) in a cooler to obtain a cooled coal gangue sinter;
• (5) crushing and grinding:
• crushing and finely grinding the cooled coal gangue sinter obtained in step (4) to obtain a coal gangue active admixture;
• (6) compounding:
• mixing the coal gangue active admixture obtained in step (5), a fly ash, a quicklime, and a gypsum according to a predetermined ratio to obtain a second resulting mixture, and then performing a mold injection, a mold removal, and a curing on the second resulting mixture to obtain a coal gangue-based cementitious material.