Application of Biomass Pellets for Iron Ore Sintering

The use of biomass as fuel might solve several technological and environmental issues and overcome certain challenges of sinter production. In particular, as revealed by comprehensive analyses, biomass can be used as fuel for iron ore sintering. In this study, we investigate the use of some raw and pyrolysis-processed biomass pellet types, namely wood, sunflower husks (SFH), and straw, for iron ore sintering. In the experiments, the pyrolysis temperature was set to 673, 873, 1073, and 1273 K, and the proportion of biomass in the fuel composition was set to 25%. It was established that the addition of biofuels to the sintering blend leads to an increase in the gas permeability of the sintered layer. The analysis of the complex characteristics of the sintering process and the sinter strength showed the high potential of wood and sunflower husk pellets pyrolyzed at 1073 and 873 K, respectively, for iron ore sintering. The analysis of the macrostructure of the sinter samples obtained using biomaterials revealed that with higher pyrolysis temperatures; the materials tend to have greater sizes and higher amounts of pores and cracks. The composition analyses of the resultant sinters revealed that with higher temperature, the FeO content of the sinters tends to increase.

USE OF CONIFEROUS WOOD BIOCHAR AS A SUBSTITUTE FUEL IN AN IRON ORE SINTERING PROCESS

The article presents the results of tests carried out at Łukasiewicz – IMŻ, in cooperation with the Institute for Chemical Processing of Coal, on the use of biochar from coniferous wood as a substitute fuel in the iron ore sintering process. It was found that, considering productivity, fuel consumption and properties of the obtained sinter, the content of the tested biochar should not exceed 10 wt% in total fuel. When using the tested biochar, the content of FeO in the sinter decreased. The sinter was characterised by better ISO T strength than when using only coke breeze. At the same time, the grindability of the ISO A sinter decreased with the increase in the content of the biochar in the total fuel. The use of the tested biochar can have a very positive effect on both the sinter strength and its reducing properties.

Studies of Conventional and New Technologies for Preparation of Iron Ore Raw Materials at Iron Making Plant of Pao Severstal to Evaluate Prospectives for Reduction of Ecological Load on Environment

The experts of Centre for Raw Materials Investigations (CRMI) have conducted research into the usage of recycled materials in the following technological processes: sintering and briquetting. Research shows variation in emissions containing sinter gases and qualitative characteristics of the finished product (cold and hot sinter strength). It is suggested that involvement of recycled waste products of steelmaking and chemical processes shall be increased using the method of vacuum extrusion. Keywords: sintering, recycled materials, sinter gas, briquettes

Analysis the Effect of Charcoal Mass Variation to Ni Content, Sinter Strength and Yield on Sintering Process of Limonitic Laterite Nickel Ore

The depletion of sulfide nickel ore and the growing of stainless steel demand each year cause the use of low-grade laterite nickel ore continues to increase. Due to very low nickel content, there is no optimal process to extract them. One of the alternative processes being developed now is the sintering-blast furnace process which produces Nickel Pig Iron (NPI). This research was conducted by sintering limonitic laterite nickel ore using charcoal as fuel and limestone as a flux. This research aims to analyze the effect of charcoal mass variation on Ni content, sinter strength, and the yield on the sintering process of limonitic laterite nickel ore. Charcoal and limestone demand calculated using energy balance and mass balance, then varied charcoal mass to feed material. Feed materials are fed in the furnace, heated at a temperature of 1200oC with 4 hours holding time. Next, the sinter yield was calculated. EDX, XRD, and Drop tests were also performed to determine Ni content, sinter compounds, and strength. The highest Ni content was 3.66% which was obtained by adding 9.9 kg charcoal. The highest sinter strength and yield also obtained by adding 9.9 kg charcoal (72.30% and 86.44%, respectively). Mayor phases which formed on sinter with 9.9 kg charcoal addition is nickel-iron oxide.

Use of magnesian fluxes of the Khalilovo deposit in sinter production

The article describes the magnesian fluxes properties of the Khalilovo deposit with different proportions of magnesite and serpentine. The results of laboratory experiments on the effect of these fluxes with various magnesite contents on the parameters of sintering process of the Kursk magnetic anomaly ores at JSC “Ural Steel” are presented. The use of experimental magnesian fluxes of the Khalilovo deposit increases the sinter strength, yield and sinter productivity. With the use of experimental fluxes instead of Bakal siderite, an increase in the sinter yield of 3 – 5 % (rel.) can be reached. In addition, the sinter productivity increases from 1.04 to 1.08 – 1.15 t/(m2·h), that is, by 4 – 10 % (rel.). The use of experimental magnesian fluxes increases the sinter strength: the tumbler index (+5 mm) increases by an average of 4 – 6 % (abs.), and the abrasion index (–0.5 mm) decreases by 0.6 – 0.8 % (abs.). Improving the strength characteristics of the sinter using magnesian fluxes of the Khalilovo deposit is due to the formation of “reinforcing” ferritic binder, as well as due to homogenization of the solidifying melt and its crystallization in the form of glass phase of the rankinite composition, which together limit the formation of β-Ca2SiO4 . The results of experimental sintering have confirmed the possibility of using experimental fluxes in the sintering production at sinter plant of JSC “Ural Steel” without changing the production technology. The rational variant for JSC “Ural Steel” is 50 % of magnesite of Khalilovo deposit in sinter rawmix. Replacement of the Bakal siderite in the production of sinter with 2 % of MgO on the magnesian flux of the Khalilovo deposit with 50 % of magnesite provides an increase in yield by 4 – 5 %, an increase in sinter strength by 5 – 6 % and an increase in sinter productivity by 8 – 10 % while keeping the iron content at the level of the “base” period.