Preparation and industrial application of blast furnace slag based filling cementitious materials
Using blast furnace slag,tailings,and cement as raw materials,sodium hydroxide was used as an activator to prepare filling materials.The effects of curing age and raw material content on the compressive strength of the filling materials were studied.Based on the requirements of industrial application practice,the optimal amount of raw materials and activators to prepare filling cementitious materials is determined,and the prepared cementitious materials in the mining filling and mining process is used to study the feasibility of the application of the filling materials prepared by the institute.The results show that the compressive strength of the filling material increases rapidly and then tends to flatten with the extension of the curing age of the specimen.It is recommended that the curing age of the filling material be above 21 d.As the sand to cement ratio increases,the compressive strength of the filling material decreases.It is recommended to have an optimal sand to cement ratio of 4.With the increase of slurry concentration,the compressive strength of the filling material first slowly increases and then rapidly increases.The recommended optimal slurry concentration is 62％-70％.With the increase of blast furnace slag content,the compressive strength of the filling material first increases and then tends to flatten.It is recommended that the blast furnace slag content be 20％.As the dosage of sodium hydroxide activator increases,the compressive strength of the filling material first increases and then decreases.It is recommended that the dosage of sodium hydroxide activator be 25％.Under the conditions of 20％blast furnace content,4 sand ash ratio,65％slurry mass concentration,and 25％sodium hydroxide content,the filling material was prepared and cured for 21 d.After curing,the compressive strength of the filling material can meet the load requirements of a goaf roof thickness of 30 meters,a rock mass bulk density of 2.5 t/m3,and a gravity load calculation of 0.75 MPa.The filling structure is stable and meets the strength requirements.
iron oreexploitationfillmechanical propertiescompressive strength
万方数据
维普
