COURSE50 (CO2 ultimate reduction in steelmaking process by innovative technology for Cool Earth 50) carried out COG and reformed COG (RCOG) injection operation trials at LKAB's experimental blast furnace in Luleå in cooperation with LKAB and Swerea MEFOS. Operation trials were successfully carried out. Input of C in both COG and RCOG injection periods decreased comparing the base period, because of increase in H2 reduction instead of C direct reduction that is a huge endothermic reaction. However poor penetration depth of injected gas from shaft tuyere made furnace efficiency worse. Hot top gas injection increased temperature of top gas and upper part of the furnace. Efficiency of hot top gas injection was not clear as sinter degradation did not occur in the base period.KEY WORDS: COURSE50; experimental blast furnace; blast furnace; CO2 emission; H2; COG; reformed COG; injection; hot top gas; sinter degradation. PrefaceCOURSE50 (CO2 ultimate reduction in steelmaking process by innovative technology for Cool Earth 50) is a national project for development of technologies for environmentally harmonized steelmaking process to achieve drastic CO2 emissions reduction in steel industry. Main targets of COURSE50 project are development of technologies to reduce CO2 emissions from blast furnace and development of technologies to capture, separate and recover CO2 from blast furnace gas. CO2 reduction technology from blast furnace consists of research of control reactions for reducing iron ore with hydrogenous reducing agents such as coke oven gas (COG) or reformed COG (RCOG). RCOG is amplified its hydrogen content in COG by utilizing newly developed catalyst and unused waste heat. Also a technology to produce high strength and high reactivity coke for reduction with hydrogen is under development.RCOG will be injected to the blast furnace through tuyeres located at lower part of the shaft of blast furnace, and COG will be injected through blast tuyeres to utilize CH4 combustion.Amount of O2 enrichment to the hot blast air has to be increased when COG is injected to the blast tuyere to maintain the flame temperature constant to compensate for heat of decomposition of hydrocarbon. It results in decrease in upper part temperature and decreased upper part temperature prolongs the residence time for sinter where disintegration is promoted. In addition, H2 may promote sinter deterioration. To prohibit prolonged residence time for sinter at low temperature range, top gas is partly combusted is injected in the upper shaft for temperature control. We call it hot top gas injection in this article.Basic and remarkable results are conducted through various laboratory tests and mathematical model calculation in COURSE50 project.3,4) H2 in COG or RCOG is expected to react with ferrous material very fast and to replace C as reducing agent of blast furnace.However, reaction in the blast furnace is much complicated because it is dominated by burden and gas distribution

The present work aims to study the high‐temperature strength of coke. Mechanisms of disintegration were evaluated using basket samples charged into LKAB's experimental blast furnace prior to quenching and dissection. Coke charged into basket samples was analysed with CSR/CRI tests and compared with treated coke from the blast furnace. Results from tumbling tests, chemical analyses of coarse and fine material, as well as light optical microscopy studies of original and treated coke have been combined and evaluated. The results indicate a correlation between the ash composition and the CSR values. Differences in the texture of the coke were noted with light optical microscopy, and a significant change in the coke texture during the CSR/CRI test conditions was found. The results suggest that the main reaction between coke and CO2 took place in isotropic areas, which was especially pronounced in coke with a low CSR. Signs of degradation were apparent throughout the coke pieces that have undergone CSR/CRI testing, but were less observable in coke reacted in the blast furnace. The results indicate that reaction with CO2 is generally limited by the chemical reaction rate in the CSR/CRI test, while in the blast furnace the reaction is limited by the diffusion rate. Coke degradation is therefore mostly restricted to the coke surface in the blast furnace.

A: We demonstrate that muon tomography can be used to precisely measure the properties of various materials. The materials which have been considered have been extracted from an experimental blast furnace, including carbon (coke) and iron oxides, for which measurements of the linear scattering density relative to the mass density have been performed with an absolute precision of 10%. We report the procedures that are used in order to obtain such precision, and a discussion is presented to address the expected performance of the technique when applied to heavier materials. The results we obtain do not depend on the specific type of material considered and therefore they can be extended to any application.

No abstract

Coke corresponds to 2/3–3/4 of the reducing agents in BF, and by the partial replacement of coking coals with 5–10% of bio-coal, the fossil CO2 emissions from the BF can be lowered by ~4–8%. Coking coal blends with 5% and 10% additions of bio-coals (pre-treated biomass) of different origins and pre-treatment degrees were carbonized at laboratory scale and with a 5% bio-coal addition at technical scale, aiming to understand the impact on the bio-coal properties (ash amount and composition, volatile matter content) and the addition of bio-coke reactivity. A thermogravimetric analyzer (TGA) connected to a quadrupole mass spectroscope monitored the residual mass and off-gases during carbonization. To explore the effect of bio-coal addition on plasticity, optical dilatometer tests were conducted for coking coal blends with 5% and 10% bio-coal addition. The plasticity was lowered with increasing bio-coal addition, but pyrolyzed biomass had a less negative effect on the plasticity compared to torrefied biomasses with a high content of oxygen. The temperature for starting the gasification of coke was in general lowered to a greater extent for bio-cokes produced from coking coal blends containing bio-coals with higher contents of catalyzing oxides. There was no significant difference in the properties of laboratory and technical scale produced coke, in terms of reactivity as measured by TGA. Bio-coke produced with 5% of high temperature torrefied pelletized biomass showed a similar coke strength as reference coke after reaction.