Effect of highly oxidizing converter dephosphorization slag on dephosphorization behaviour of molten steel

Abstract

In order to study the effect of highly oxidizing dephosphorizing converter slag on the migration behaviour of phosphorus in molten steel, an industrial test was carried out on a 300t dephosphorizing converter in a steel plant by the duplex method. Theoretical analysis shows that when the temperature is low, the basicity is 1.5 and the FeO content is 25%-30%, the phosphorus capacity of slag is stable. The industrial test results show that when the temperature is 1630K-1665K, the basicity is 1.05-1.25, the FeO content is 35%-40%, and the dephosphorization efficiency of the converter can generally reach above 60%. XRD and SEM-EDS analysis results showed that phosphorus was mainly enriched in 2CaO•SiO 2 -3CaO•P 2 O 5 solid solution. Infrared analysis results show that under the condition of high FeO and low basicity, properly increasing of basicity is beneficial to reduce the degree of polymerization of dephosphorization slag.

Composition optimization and high-temperature characteristics of fluorine-free CaO-SiO 2 -FeO-B 2 O 3 -MnO dephosphorization slag

“…The specific experimental factors and levels are listed in Table 2. Dephosphorization is an exothermic reaction, a large number of industrial tests and research show that the temperature of dephosphorization should be controlled at about 1400°C [30][31][32]. Therefore, the dephosphorization temperatures were set to 1360, 1380, 1400, and 1420°C, and the viscosity at the temperature was recorded.…”

Behavior of Carbothermal Dephosphorization of Phosphorus-Containing Converter Slag and Its Resource Utilization

“…Our team has conducted a considerable amount of research on the carbothermic reduction of slag [19][20][21][22][23][24], and, based on the efficient resource utilization of the carbothermic reduction of converter slag, a new process of "circulating steelmaking by gasification dephosphorization of converter slag" was put forward. Coke was added during the slag-splashing and furnace-protection stages of the converter to realize gasification dephosphorization, and the slag after gasification dephosphorization was reserved for recycling in subsequent furnaces, which could then be used as hot slag to realize low-temperature dephosphorization.…”

Ionic analysis of the effect of temperature on dephosphorization capacity of silicate slags

“…Wen [7] proposed that the furnace temperature should be controlled between 1320°C and 1360°C to maintain better kinetic conditions for the slags. But some researchers [8] considered that the optimal smelting ending temperature of BOF should be around 1402°C to achieve the best dephosphorization effect.…”