Development of Cementing Material of Fine Full-Tailings Filling by Slag Powder

Abstract

The cementing material of fine full-tailings is developed with the fine tailings of Anshan Iron and Steel Company as aggregates, the water quenching slag of blast furnace as the main active material, and the desulphurized ash residue as one of the main activator materials. This paper explores the effects of composite activator with different content on the compressive strength of the filling body of the cementing material of fine full-tailings filling. After orthogonal test and analysis with different statistical methods, the optimum formula is obtained and verified by experiment. The test results indicate that the compressive strength of the new cementing material at 28 day is 2.01 times of that of cement under the same proportion. The X-ray diffraction and scanning electron microscopy are used to analyze the composition of hydration products and micro-morphology of the new cementing material. The results show that the hydration products of the cementing material are mainly flocculent C-S-H gel, and the more the hydration products are, the more compact the filling body structure will be, which form a network structure with higher strength. The new cementing material could replace cement and most of the filling materials are the waste, which could significantly reduce the cost of filling mining and is environmental-friendly. If the scientific filling technology is combined, the mine tight-filling ratio can be significantly improved, which is conducive to the safety of mining production as well as the mine construction cost control.