Development of Continuous Blast Furnace Slag Solidification Process for Coarse Aggregates

Behavior of Crystallization on a Continuous Solidification Process of Blast Furnace Slag

“…Plate-Shaped Solidified Slag and Coarse Aggregate Base on the solidification conditions for reducing the porosity of blast furnace slag reported by Tobo et al, 3) a continuous blast furnace slag solidification facility was constructed. 4) Figure 1 shows the outline of the equipment, and Table 1 shows the equipment specification.…”

“…13. The density of the slag at room temperature was 2.93 g/cm 3 . The density at 1 373 K decreased by approximately 3% in comparison with the density of room temperature.…”

“…Based on the measured values, the initial temperature of the slag T S0 was set at 1 653 K and the initial temperature of the mold T M0 was set at 373 K. Three boundary conditions were assumed, 1) slag/air contact surface, 2) slag/mold contact surface and 3) mold/air contact surface. For the thermal resistance of the slag/mold interface, the 0.0009 (m 2 K)/W used by Tobo et al 3) and 0.009 and 0.00009 (m 2 K)/W were studied. In this analysis, conditions in line with the actual measurements were examined by changing the upward and downward heat transfer coefficients in the range of 0-20 W/(m 2 K).…”

“…1,2) In order to produce air cooled blast furnace slag with low water absorption similar to that of natural stone, the authors developed a continuous blast furnace slag solidification process. 3,4) This process comprises processes in which molten blast furnace slag is poured into molds to a thickness of 20-30 mm, solidified into plates in a short time of about 2 min, and then dropped from the molds into a slag pit and air cooled. This process makes it possible to suppress the formation reactions of gases such as sulfur, nitrogen, etc.…”

Behavior of Crack Generation of Slag in Continuous Solidification Process of Blast Furnace Slag

“…In previous research, [1][2][3][4][5][6] we demonstrated that plateshaped solidified slags with few pores and low water absorption suitable for use as coarse aggregate for concrete can be obtained in a continuous process by pouring molten blast furnace slag into steel molds to a thickness of approximately 25 mm. These desirable properties can be achieved because pore formation and growth are suppressed by rapidly solidifying molten slag.…”