| Backfill mining with superhigh-water material is a kind of filling methods widely used now. The main cementious component of superhigh-water material now used is just sulphoaluminate material.This paper proposes that aluminate cement is used as base material to form superhigh-water material in order to expand its raw materials sources. Through the uniform recipe design obtains the proportioning scope of raw material(calcium aluminate cement, gypsum and lime). Research has shown that the proportion of calcium aluminate cement have a significant impact on the mixture materials. When the content of calcium aluminate cement is 50% to 90%, gypsum and lime amount are more than 5% respectively, the material can reach the state of initial setting. First of all, fixed any one of lime, gypsum or clinker, and adjusted the amount of others, the high water-solid ratio reached.The results show that: active ingredients in calcium aluminate cement, types of natural gypsum, particle size distribution of gypsum and water temperaturehave a significant effect on initial setting time of mixture material. The content of CA and CA2 which is active ingredients in calcium aluminate cement concerns with the proportion of calcium aluminate cement in mixture material. The higher content of CA and CA2 is under the same conditions, the less proportion of calcium aluminate cement is. Gypsum A is better than gypsum B. The particle size distribution of gypsum has no effects on the ratio of mixture material, but has effects on initial setting time. The smaller particle size of gypsum is, the shorter the initial setting time of the blended material is. When water temperature is close to the ambient temperature, the initial setting time of the mixture material will be shorter.This paper focuses on the impact of accelerator on initial setting time. After 28 kinds of addditives tested, it is concluded that two kinds of them, that is, No. 2 and 8 have a significant effect on the mixture materials and the optimum additive proportion are 4% and 4.8%, respectively. The results show that the smaller the radius of anionic and the higher of valence state of addditives, the shorter of initial setting time. At the same time, the same additives from different source have different influence on the initial setting time, but have no differences between the optimum quantities each other. Meanwhile, the adding modes have significant impact on the initial setting time and the compressive strength of mixture materials.Through the above research, a superhigh-water material with water to solid ratio 10:1(volume fraction is more than 96%) is obtained. Under the optimal conditions, when the water to solid ratio is 10:1, 8:1, 6:1, 7d compressive strength can reach 0.19 MPa, 0.31 MPa and 0.53 MPa, respectively, which meet the strength requirements of superhigh-water material.Finally, this paper investigates the compressive strength, viscosity of fluid and resistance to weathering of the superhigh-water material formed. Research shows that strength of consolidated body and the changes of viscosity can meet the requirement of superhigh-water material, while resistance to weathering is similar with sulphoaluminate superhigh-water material which is more easily to be weathered. The consolidated body has the characteristics of early strength and rapid hardening, which 1d strength can reach more than 75% of the ultimate strength. Long-term strength increased with increasing time, but the growth rate decreases and after 7 days compressive strength was basically stable. Single slurry viscosity has little change with water to solid ratio and time, which can meet the industry requirements of superhigh-water for pipeline transport. The change of mix slurry viscosity with time is larger. The viscosity increases linearly at first, while near the initial setting time the viscosity instantly increases.The study indicates that it is feasible to produce superhigh-water material with aluminate cementious mater as a main component. |
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