Through the research on the mechanism of iron ore sintering process, we used Fluent software to simulate the sintering process and establish a mathematical model of heat and mass transfer; moreover, we used the sintering cup experiment to verify the reliability of the model. The experimental results showed the following: when adding biomass fuel, the thickness of the material layer with the temperature higher than 1573 K decreased slightly; meanwhile, the thickness of the material layer with the temperature higher than 1723 K decreased drastically. Comparison of the emission content of SO₂ in conventional sintering and sintering with biomass fuel showed that sintering with biomass fuel could reduce SO₂ content in sintering flue gas. Considering sinter properties and SO₂ emission reduction effect, sintering material that was added 30% biomass fuel to replace coke breeze could ensure the ore-forming process, and could realise the environment-friendly production.

High content amorphous phase blast furnace slag beads were prepared by gas quenching blast furnace slag (BFS), which could not only avoid a series of environmental problems caused by traditional water quenching methods, but also significantly increase the added value of BFS subsequent products. In this paper, the granulation mechanism of BFS and the amorphous phase formation mechanism of slag beads were studied by combining the physical properties of BFS and the granulation effect. The results showed that the viscosity of BFS decreased with the increase of basicity; the bigger the basicity, the higher the bead formation rate, the smaller the particle size and the more regular the slag shape. The smaller the basicity, the greater the crystallization activation energy and the smaller the Avrami exponent, which indicated that the crystal was more difficult to nucleate and grow. The increase of the cooling rate could effectively inhibit crystal precipitation. Therefore, the high basicity and cooling rate could not only guarantee the high bead formation rate of BFS, but also ensure the high content amorphous phase of slag beads.

Most of the air pollutants in the steel industry come from the sintering process, and the air pollutants produced by the sintering process mainly come from the sinter fuel (coke breeze). The S and N content of biomass fuel is low; therefore, biomass fuel is used instead of coke breeze for sintering to reduce the emission of the sinter flue gas pollutants. However, the use of biomass fuel reduces the sintering layer temperature, which results in the deterioration of the sinter properties. In order to ensure the quality of sintering base on biomass fuel, the thermodynamic calculation and related experiments were carried out, the effects of different basicity, MgO and Al₂O₃ content on the formation of low melting point minerals in sintered mixture were studied, and the suitable composition of sintered mixture was determined in this paper, so as to reduce the liquid phase formation temperature of sinter and increase in biomass fuel addition, which provided theoretical support for the application of biomass fuel in sintering. Experimental results indicate that the suitable conditions for the low-temperature sintering were a basicity of 2.0, and MgO and Al₂O₃ contents of 1.0% and 1.8%, respectively. Under this condition, more biomass fuel can be used to replace coke breeze, and the emission of flue gas pollutants can be greatly reduced.

In order to overcome the environmental pollution caused by traditional water-quenching slag treatment and recover a large number of waste heat from blast furnace slag (BFS), the dry granulation process had attracted more and more attention, in which the granulation process was the key. The slag granulation and the crystallization mechanism of the BFS were studied, and the hot experimental results were analysed. The results showed that the viscosity of BFS decreased with increasing basicity, thus was beneficial to the broken of BFS. The higher the basicity, the smaller the crystallization activation energy of BFS, and the bigger the crystal growth index, which was more beneficial to the crystal nucleation and growth of BFS. Reducing the basicity or increasing the cooling rate could be more beneficial to the preparation of amorphous slag beads. The basic slag could obtain the same amorphous results as acidic slag by increasing the gas quenching speed.