Effects of Grinding Aids on Grinding Fineness and Activity Index of Ground Blast Furnace Slag

This paper investigates and compares the effects of five kinds of grinding aids, i.e., triethanolamine, calcium lignosulphonate, sodium oleate, sodium tripolyphosphate and glyceryl alcohol, on grinding fineness and activity index of ground blast furnace slag. The results show that, both calcium lignosulphonate and sodium oleate are effective grinding aids, which can improve grinding fineness and activity index of ground blast furnace slag significantly. The optimum amounts of calcium lignosulphonate and sodium oleate are 0.2% and 0.1% respectively. Under that optimum condition, the d₉₀ and specific surface area of ground blast furnace slag are 43.77um, 35.64um, and 424.75m²/kg, 530.47m²/kg, respectively. The activity indices of the ground products meet the technical requirements of GB/T18046-2000 S95. As to the fineness uniformity of ground products, sodium oleate plays a better role compared with calcium lignosulphonate, which is more suitable for production of cement and concrete.