Abstract:
Using some kind of laumontite tailing in Gansu Province as raw material, attapulgite clay as binder, and coal powder as pore-forming agent, the porous ceramsite was prepared by a high-temperature calcination process. The effects of the amount of binder, calcination temperature, calcination time and the amount of pulverized coal on the properties of ceramsite samples were systematically studied, and the optimized preparation process was obtained. The microstructure and phase composition of the samples were detected and analyzed by SEM and XRD characterization methods. The results show that the optimal mass ratio of laumontite tailings, attapulgite clay and coal powder is 42.5 GA6FA 42.5 GA6FA 15, the calcination temperature is 1 100 ℃, the calcination time is 30 min, and the heating rate is 20 ℃/min. The bulk density of the obtained sample prepared under optimal conditions is up to 692 kg/m
3, the fracturing force is 116.4 N, the water absorption is 25.3%, and the cylinder compressive strength is 4.7 MPa. The performance meets the requirements of the national standard for the ceramsite. In addition, the prepared ceramsite is porous, and the mineral phases such as laumontite and palygorskite in the raw material are transformed into quartz and albite under high temperature conditions. This technology provides an effective way for the comprehensive utilization of sand and gravel aggregate tailings.