The effect of carbon dioxide (CO2) on the desulfurization of sintering flue gas with hydrate (Ca(OH)2) as an absorbent was investigated, and the formation of calcium carbonate (CaCO3) and its effect on the desulfurization was discussed. The competitive relationship between carbon dioxide (CO2) and sulfur dioxide (SO2) with the deacidification agent in sintering flue gas is discussed thermodynamically, showing that sulfates are more likely to be generated under high oxygen potential conditions and that SO2 reacts more preferentially than CO2 under a thermodynamic standard state. The amount of produced CaCO3 increases under the condition that the CO2 concentration is absolutely dominant to SO2 in the sintering flue gas atmosphere. The effect of temperature, humidity and CO2 concentration on the desulfurization of Ca(OH)2 are discussed experimentally. The increasing temperature is not conducive to desulfurization, and the humidity can promote desulfurization, while excessive humidity could inhibit desulfurization. The suitable relative humidity is 20%. In situ generated calcium carbonate has a certain desulfurization effect, but the desulfurization effect is not as good as Ca(OH)2. However, a large proportion of CaCO3 was produced in the desulfurization ash under the condition that CO2 concentration was absolutely dominant to SO2 in the sintering flue gas atmosphere.

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The effects of the application of iron coke in hydrogen-rich blast furnace atmosphere on the softening and melting performance of burden were studied.The results indicated that with the increase in hydrogen content, the cohesive zone of mixed burden became narrower and the permeability of charge was improved, and the suitable hydrogen content was 10vol.-%. The application of iron coke could promote the iron ore reduction and carburizing of iron, decrease the melting temperature by 1-10°C, decrease the dripping temperature by 5-16°C, narrow the cohesive zone, improve the air permeability with S value decrease of 3.19-13.87 kPa °C, and reduce the dissolution loss of coke and ensure the skeleton function of coke. The suitable burden structure was confirmed as follows, i.e. the ratio of pellets and sinter is 4:6, and the ratio of iron coke and coke is 2:8.