It has been found through practice that the finished ore produced by the grate machine rotary kiln process has the characteristics of uniform quality, good metallurgical properties, more usable fuels, and strong adaptability to raw materials. This article introduces what equipment should be equipped with this production line equipment.

The results show that the optimal drying, preheating, and roasting temperatures of limonite pellets are 200 °C, 700 °C, and 1250 °C, respectively, and the optimal roasting time is 20 min, when the diameter of the pellets is 8–13 mm. The compressive strength of limonite pellets with the addition of 1.5% bentonite was the highest, meeting the demands of a general blast furnace, based on which the iron grade of limonite pellet ore was increased by 10.63%.

In this experiment, a pellet preparation method was investigated to study the drying, preheating, and roasting properties of limonitic iron ore from a plant in Yunnan. The aim was to improve the subsequent iron-making process of limonitic iron ore and make it a substitute for sintered ore. This substitution would reduce the amount of blast furnace slag in the iron-making process. Bentonite is commonly used as a primary binder in many pelletizing plant operations. However, its excessive usage leads to a higher risk of slagging and coking in the furnace.

First, amine-based post-combustion capture with a 95% capture rate was considered as the benchmark, as it is currently commercially available. A second, novel configuration integrated the Midrex process with pressurized chemical looping—direct reduced iron (PCL-DRI) production. The amine capture configuration is most sensitive to the cost of steam generation, while PCL-DRI is more sensitive to the cost of electricity and the makeup oxygen carrier. An iron-based natural ore is recommended for PCL-DRI due to the low cost and availability. Based on the lower costs compared to amine-based post-combustion capture, PCL-DRI is an attractive means of eliminating CO2 emissions from DRI production.

The replacement of the blast furnace—basic oxygen furnace (BF-BOF) steelmaking route with the direct reduced iron—electric arc furnace (DRI-EAF) route reduces the direct CO2 emissions from steelmaking by up to 68%; however, the DRI shaft furnace is one of the largest remaining point source emitters in steelmaking. The capital and operating expenses of two potential nearly carbon-neutral DRI process configurations were investigated as a modification to a standard Midrex DRI facility.

To overcome the limitations of the above two processes, and to achieve a more efficient direct reduction process of iron ore, the possibility of combining these two methods was investigated. The experiments focused on performing an initial direct reduction using ore-coal composite pellets followed by a second stage gas reduction. It was assumed that the initial reduction of the carbon composite pellets would enhance the efficiency of the subsequent reduction by gas and the total reduction efficiency. The porosity, as well as the carbon efficiency for direct reduction, were measured to determine the optimal conditions for the initial reduction, such as the size ratio of ore and coal particles. Thereafter, further reduction by the reducing gas was carried out to verify the effect of the preliminary reduction. The reduction kinetics of the reducing gas was also discussed.

Recently, direct reduced iron (DRI) has been highlighted as a promising iron source for electric arc furnace (EAF)-based steelmaking. The two typical production methods for DRI are gas-based reduction and reduction using carbon composite pellets. While the gas-based reduction is strongly dependent on the reliable supply of hydrocarbon fuel, reduction using ore-coal composite pellets has relatively low productivity due to solid–solid reactions.

In this paper, the research status of the thermal state, reduction mechanism of iron-bearing burden, coke degradation behavior, and formation of the cohesive zone in various areas of blast furnace after hydrogen-rich smelting is summarized, which can make a more clear and comprehensive understanding for the effect of H2 on blast furnace ironmaking.

In the past 20 years, many sintering plants have continued to innovate traditional sinter material preparation technology. Japanese companies such as Sumitomo and Nippon Steel were the first to use vertical intensive mixers for mixing sinter materials. Through research and practice at Sumitomo Wakayama Third Sintering Plant, the use of a vertical powerful mixer instead of a cylindrical mixer has enhanced the mixing effect of the sintered raw materials, and the corresponding granulation effect has also been enhanced, ultimately making the sintered raw materials highly breathable. The sintering speed is increased by 10%~12%, and the coke powder addition ratio can be reduced by 0.5%.

Rotary kiln is a commonly used production equipment in modern industrial production. It is widely used in chemical industry, building materials, non-ferrous metallurgy, ferrous metallurgy and other industries, such as: drying and oxidation roasting of materials in the chemical industry; drying of raw materials in the building materials industry and dolomite roasting; oxidative desulfurization of raw materials in the nonferrous industry, synthesis of reagents; drying of ore powder, preparation of smelting flux, production of oxidized pellets, production of direct reduced iron, and smelting of ferronickel in the steel industry.