Conventional Blast Furnace Research Articles

Power to gas and top gas recycling integration in an oxygen blast furnace steelmaking industry

A new process concept integrating power to methane with top gas recycling in an oxygen blast furnace (BF) is investigated to reduce the emission intensity of steelmaking. Power to gas produces synthetic methane using hydrogen (H2) generated by an electrolyser operated with renewable electricity, and CO2 captured from the BF gas by amine scrubbing supplied with heat from the methanation process. The clean gas from the amine scrubbing is recycled and injected in the BF (via top gas recycling), together with synthetic methane. A parametric analysis is performed to vary the amount of top gas recycled (from 0 kg/tHM to 270 kg/tHM). Based on the results, CO2 equivalent emissions can decrease by 34% using power to gas technology, and by 30% with power to gas and top gas recycling (compared to conventional BFs). Nevertheless, if both integrations are present, additional benefits on the specific energy consumption (12.0 MJ/tHM), and specific cost (130 €/tHM) are achieved, compared to only applying power to gas (17.5 MJ/tHM and 233 €/tHM). In all cases, the downstream thermal energy needs of the steel plant are fulfilled, contrarily to conventional top gas recycling concepts. The main conclusion is that top gas recycling should be considered together with PtG technology, and vice versa, when integrated in blast furnace ironmaking, in order to both abate emissions while supplying downstream energy needs.

Mathematical Modeling and Analyses of Integrated Process with Blast Furnace Iron Making and Co-gasification of Coal-COG-BF Top Gas

For the blast furnace iron-making process which depends on the coke seriously and is the largest CO2 emission source in iron and steel industry, a novel technology integrated the blast furnace process and co-gasification of coal-COG-BF top gas is investigated and examined its potential of energy conservation and CO2 emission reduction. The mathematical model of the whole integrated process is established based on mass and heat balance principles. And typical operation analyses for the integrated process are demonstrated by this model. The results indicate that it takes about 4 times for the unsteady process caused by the recycling of BF top gas to reach steady. Compared with conventional blast furnace process, the coke ratios in two integrated process cases selected decrease by 33.5kg/tHM and 81.3kg/tHM obviously, and the fuel ratios decrease 1.1% and 8.2% due to the increase of coal ratios by 27.9kg/tHM and 39.1kg/tHM. The energy consumption decreases by 8.3% and 10.8%. And the CO2 emission decreases by 37.0% and 42.9%.

Low carbon optimal planning of the steel mill gas utilization system

Decarbonization of the steelmaking industry is imperative in achieving the carbon neutrality target. This paper proposes a two-stage low carbon robust planning method for the steel mill gas utilization system (SMGUS), which is the major CO2 emission source of the conventional blast furnace route based-steelmaking plant. The planning aims to find the optimal installed capacities and relevant deployment time of multiple low-carbon technologies, such as renewable energy, energy storage, hydrogen energy and carbon capture & utilization, so that the demand of steel production can be met in an economically competitive and environmentally friendly way. Case studies are carried out on the low-carbon planning of a steelmaking plant with annual production of 1.5 million tons of crude steel, in which different carbon market conditions and CO2 reduction routes are considered. The results show that the low carbon planning can reduce the CO2 emissions to 1.22 tons per ton of steel by 2045–2050 through the proper deployment of the low carbon technologies. The CO2 emissions can be further reduced to 0.31 tons per ton of steel if the BF-BOF process is replaced by H2-DRI and EAF technologies. This paper presents an effective planning method for the decarbonization of steelmaking plant.

Rigorous environmental and energy life cycle assessment of blast furnace pig iron in Brazil: The role of carbon and iron sources, and co-product utilization

Iron and steel are valuable commodities worldwide. Pig iron is produced mainly by blast furnaces, being the primary raw material used in steel manufacturing. The ironmaking sector is intensive in energy use and greenhouse gas emission; however, detailed information on further environmental impacts concerning the blend of material sources and co-product utilization as well as a rigorous application of the life cycle assessment (LCA) method are scarce. This study aimed to assess the environmental and energy performance of the production of 1.0 t of pig iron from cradle-to-gate via LCA. Global warming potential (GWP), renewable and non-renewable cumulative energy demand (CEDR and CEDNR), fossil resource scarcity (FRS), mineral resource scarcity (MRS), blue water footprint (WF), and land use (LU) were assessed in five scenarios in the Brazilian context, being S0: the baseline scenario with coke as a carbon source; S1: partial utilization of by-/co-products (top gas and slag), representing the current industry practice; S2: carbon and iron input blends proportional to the current industry practice; S3: current industry mix (S1 and S2 combined); and S4: ex-ante (forecast) scenario with an enhanced blend of inputs and maximum utilization of co-products. Results show that, when evaluated against an unrefined but realistic fossil-based state of the technology (S0), the existing practice in co-product utilization (S1) provided more gains in terms of GWP, CEDNR, FRS, and MRS (11 % on average) than the current iron and carbon input blends (S2, 9 % on average) if compared side-by-side. The current industry mix (S3) showed further improvement in environmental and energy performance (22 % on average) compared with the baseline scenario (S0), while the forecasted scenario (S4) indicated additional gains, reducing GWP by 47 % (down to ~1 t CO2 eq), CEDNR by 69 %, FRS by 70 %, MRS by 12 %, and WF by 5 %. The GWP, CEDNR, and FRS presented the greatest improvements with a significant statistical difference, and using charcoal as a carbon source was key in that regard, despite the great increase in CEDR (3× for biomass) and LU (2×) indicators suggesting that a robust sustainable wood supply chain will be decisive for the sector strategy. The sensitivity analysis (SA) and benchmarking of the ex-ante scenario (S4) showed notable competitiveness of such pig iron in the global market, especially for carbon and energy footprints, reaching 0.69 t CO2 eq t−1 pig iron and 4.6 GJNR t−1 pig iron from 100 % sustainable charcoal and including rail logistics (SAiv), which are from 2× to 5× smaller than those of any conventional blast furnace pig iron reported in the consulted literature.

Pressure Drop and Gas Flow in an Oxygen Blast Furnace Analyzed by a Combination of Experimentation and a Porous Model

As a modification of the conventional blast furnace (BF), the top gas recycling-oxygen blast furnace (TGR-OBF) has been continuously studied in the context of the technological transformation of low-carbon metallurgy. As it has a set of new gas inlets in the stack and changes the blast operation system in the hearth, the pressure drop and the in-furnace gas flow are the primary problems to be solved in the TGR-OBF’s industrialization. In this paper, a two-dimensional model of a whole blast furnace, based on a softening-and-melting experiment and porous-medium theory, is established. The in-furnace pressure drop and the gas velocity with different oxygen concentrations and tuyere heights are studied. The results show that the suitable height of the stack tuyere is the same as that of the elevation as the cohesive zone inside the furnace. With the gradual increase in oxygen enrichment, the permeability of the cohesive ore layer (COL) increases, while the gas flow through the coke layer (CL) decreases gradually up to 10%. The simulation results provide a theoretical basis for the TGR-OBF to reduce the coke rate and keep the pressure drop from increasing, or even to enable it to decrease.

The CO2 reduction potential for the oxygen blast furnace with CO2 capture and storage under hydrogen-enriched conditions

The CO2 emission reduction of blast furnace (BF) is critical to the clean and sustainable development of the steel industry. Herein, we studied the CO2 emission reduction potential of oxygen blast furnace (OBF) and oxygen blast furnace under hydrogen-enriched conditions (OBFh-ec) with CO2 capture and storage, via establishing mathematical models, including the stack and bosh model, the combustion zone model, and the gas recycling system model. The in-furnace status, mass and energy consumption, and the CO2 emission of the OBF under four typical conditions were analyzed based on the models. Considering the relationship between BF and upstream and downstream processes, the CO2 emission that BF processes should bear in an integrated steel mill was calculated. The results indicated that, compared with the conventional BF, the CO2 emissions of OBFh-ec decreased by 9-14%, and decreased by 38-44% when the CO2 storage technology was used. Importantly, the hydrogen-enriched injection will affect the carbon emission reduction effect of CO2 capture and storage. The fuel consumption and the comprehensive energy consumption of OBFh-ec decreased. The mechanism in the CO2 emission reduction of OBFh-ec was interpreted based on analyzing the chemical reactions, temperature, and mass flow in the furnace. This study has important implications for understanding the CO2 reduction potential of the OBF using CO2 capture and storage with hydrogenous fuel injections.

Suitability of Auger Pressing Briquettes for Blast Furnace Use Based on Laboratory Tests

Briquetting is a process in which fine materials unsuitable for use as such are agglomerated to achieve a larger particle size. Auger pressing is a novel briquetting method to efficiently improve the recycling of by-products from iron and steelmaking. The high-temperature properties of auger pressing briquettes mainly consisting of blast furnace sludge and mill scale were evaluated. The aim was to determine the suitability of the briquettes for blast furnace (BF) ironmaking by studying the reduction, swelling, and cracking behavior using a laboratory-scale furnace. The blast furnace simulator (BFS) capable of performing non-isothermal reduction experiments with changing gas compositions was used to simulate the different stages of reduction up to 1100 °C in an atmosphere with N2, CO, and CO2 gases. A commercial olivine pellet and a conventional industrial BF briquette were used as reference samples. The sample weight losses were monitored by thermogravimetry, swelling as a change in the volume, and cracking by visual inspection. The samples were analyzed using microscopes and an elemental analyzer. Based on the BFS experiments, the briquettes proved to be a promising raw material for BF use. They were of a self-reducing quality due to their carbon content and showed reduction to metallic iron faster compared to the reference samples. The swelling was slight, and despite the minor cracking the structure of the briquettes did not degrade.

Sustainable transition of the primary steel production: Carbon footprint studies of hot-rolled coil according to ISO 14067

A shift away from traditional carbon-based towards a hydrogen-based steel production has to be stepwise so that technological challenges can be solved simultaneously to various other challenges like the evolution of green markets, political framework as well as the creation of hydrogen supply. First bridge technologies towards hydrogen-based steelmaking are crucial to generate a stable demand for hydrogen so that hydrogen supply can follow. Injection of hydrogen into existing blast furnaces is a prominent example to reduce greenhouse-gas emissions without the ambition to reach complete carbon neutrality. A subsequent next step on the way towards climate neutrality are modern Direct reduction units. This technology is able to reduce Iron oxides by natural gas and hydrogen, respectively. Within the existing plants Direct reduction units can be incorporated in various ways over time, thus offering a gradual and in the end complete transition to hydrogen and electricity based production. Since LCA studies provide crucial input for political and market-economy decision-making, the LCA community is of great importance for giving direction of transformation processes. Like other industries, the steel industry needs an allocation approach for greenhouse gas emission savings to evolve green markets, of which the methodology shall be discussed within the life cycle community. The current study presents carbon footprint assessments (ISO 14067) of hot-rolled coil for different future production scenarios. The following production routes are investigated: - Conventional blast furnace – basic oxygen furnace route - Injection of H2 into a blast furnace - Input of H2-based direct reduced iron (DRI) into a blast furnace - H2-based direct reduction combined with electrically melting from renewable energy.

Investigation on the Reaction Behaviour of Partially Reduced Iron under Blast Furnace Conditions

The reaction behaviour of partially reduced iron (PRI) was studied to understand the effect of PRI utilisation in the blast furnace process. For quantitative analysis, the reaction behaviour of PRI under typical operating conditions of a blast furnace was measured using the thermogravimetric method along with the reduction behaviour of hematite and sinter. Experimental results indicated that the reoxidation behaviour of the PRI under the conditions of the upper shaft of the blast furnace retarded the indirect reduction rate in the lower shaft. The rate constants derived from the grain model, experimental results of scanning electron microscopy, and porosimetry analysis indicated that the phenomenon of reduction retardation of PRI under the conditions of the lower shaft originated owing to the reoxidation of PRI, resulting in the blockage of pores. The reaction behaviour considering the reaction characteristics of PRI was derived under conventional blast furnace conditions.

Evaluation of biomass-based production of below zero emission reducing gas for the iron and steel industry

The present paper focuses on the production of a below zero emission reducing gas for use in raw iron production. The biomass-based concept of sorption-enhanced reforming combined with oxyfuel combustion constitutes an additional opportunity for selective separation of CO2. First experimental results from the test plant at TU Wien (100 kW) have been implemented. Based on these results, it could be demonstrated that the biomass-based product gas fulfills all requirements for the use in direct reduction plants and a concept for the commercial-scale use was developed. Additionally, the profitability of the below zero emission reducing gas concept within a techno-economic assessment is investigated. The results of the techno-economic assessment show that the production of biomass-based reducing gas can compete with the conventional natural gas route, if the required oxygen is delivered by an existing air separation unit and the utilization of the separated CO2 is possible. The production costs of the biomass-based reducing gas are in the range of natural gas-based reducing gas and twice as high as the production of fossil coke in a coke oven plant. The CO2 footprint of a direct reduction plant fed with biomass-based reducing gas is more than 80% lower compared with the conventional blast furnace route and could be even more if carbon capture and utilization is applied. Therefore, the biomass-based production of reducing gas could definitely make a reasonable contribution to a reduction of fossil CO2 emissions within the iron and steel sector in Austria.

Sustainable Recycling of Waste Epoxy, Biomass and Its Blends as Alternative Reductants for Hematite Using Microwave Technology

The circular economy demands that products are reused, recycled or reproduced into another product for a sustainable environment. The rising amount of greenhouse gases in the atmosphere calls for clean fuels to be used in production. Biomass is known to contain a considerable amount of carbon likewise, epoxy which is a thermosetting plastic. Laboratory studies on the use of waste epoxy, bamboo and coconut shells (CNS) as reductants were performed on reagent grade ferric oxide (96.89 wt. % Fe 2 O 3 ) using a domestic microwave oven of 1400 W power rating. Composite pellets of 30% and 70% were formed from the mixtures of ferric oxide and carbonaceous materials respectively. The composite pellets were fired in a microwave oven for 30 minutes. The percent mass loss and extent of reduction were then calculated after firing. The results depict that metallic iron can be produced effectively using epoxy, bamboo, CNS and their blends as reducing agents. Analysis of the results indicates a blend of 35 % Bamboo, 35 % CNS and 30 % epoxy attained the highest reduction of 95.41 %, which was closely followed by a blend 30 % epoxy and 70 % CNS of 92.92 %. The individual carbonaceous materials also recorded significant reduction of 74.76 %, 78.22 % and 83.65 % for bamboo, CNS, and epoxy respectively. From the laboratory results obtained, waste epoxy, coconut shells and bamboo can be recycled in an eco-friendly and sustainable manner through their usage as an alternative reductant for ferric oxide. Also, the success achieved with reduction in the microwave environment can catalyse the gradual shift from the conventional blast furnace used in iron production.

Effect of Nitrogen-less Reducing Atmosphere on Permeability of Cohesive Layer in Blast Furnace

Recently, demands for reduction of CO2 gas emission in iron making process are increasing. For further reduction of CO2 gas emission, a method of capturing carbon dioxide from blast furnace exhaust gas has been studied. The oxygen blast furnace using pure oxygen for blast does not contain nitrogen in the exhaust gas and that is more advantageous than conventional blast furnace in the point of view of CO2 separation energy. Although the oxygen blast furnace has been studied with the experimental furnace, the experimental furnace was not sufficiently investigated on the properties of cohesive layer because of the small load of burden materials. Therefore, in this study, the properties of cohesive layer of the oxygen blast furnace were studied.

Reduction Study of Iron Ore Pellets with Wooden Bark Char

In the process of iron making reduction of iron ores to metallic iron is done by coke which acts as a reluctant. As, both the reduction process, conventional blast furnace and DRI technologies are driven by the Boudouard reaction, so there is a probability for substituting of coal/coke with biochars, which could provide a good source of carbon and energy for the reduction. Hence, the utilization of bio char can become an emerging technology and better option for replacing coking coal for metallurgical purposes. This study includes characterization and comparative study of reduction of Iron ore pellets and fines using Wooden Bark Char (WBC) as one of the biomass waste. From the results, reduction of iron-ore fines with comparable ratios with WBC gives the maximum degree of reduction than reduction of iron-ore pellets. Thus, WBC can play an important role in behind the premium quality of coking coal reserves.

Model Study on Burden Distribution in COREX Melter Gasifier

COREX is one of the commercialized smelting reduction ironmaking processes. It mainly includes two reactors, i.e., a (reduction) shaft furnace (SF) and a melter gasifier (MG). In comparison with the conventional blast furnace (BF), the COREX MG is not only equipped with a more complicated top charging system consisting of one gimbal distributor for coal and eight flap distributors for direct reduction iron (DRI), but also the growth mechanism of its burden pile is in a developing phase, rather than that in a fully-developed phase in a BF. Since the distribution of charged burden plays a crucial role in determining the gas flow and thus in achieving a stable operation, it is of considerable importance to investigate the burden distribution influenced by the charging system of COREX MG. In the present work, a mathematical model is developed for predicting the burden distribution in terms of burden layer structure and radial ore/coal ratio within the COREX MG. Based on the burden pile width measured in the previous physical experiments at different ring radii on a horizontal flat surface, a new growth mechanism of burden pile is proposed. The validity of the model is demonstrated by comparing the simulated burden layer structure with the corresponding results obtained by physical experiments. Furthermore, the usefulness of the mathematical model is illustrated by performing a set of simulation cases under various charging matrixes. It is hoped that the model can be used as a what-if tool in practice for the COREX operator to gain a better understanding of burden distribution in the COREX MG.

Comparison of Energy Consumption and CO2 Emission for Three Steel Production Routes—Integrated Steel Plant Equipped with Blast Furnace, Oxygen Blast Furnace or COREX

High CO2 emissions and energy consumption have greatly restricted the development of China’s iron and steel industry. Two alternative ironmaking processes, top gas recycling-oxygen blast furnace (TGR-OBF) and COREX®, can reduce CO2 emissions and coking coal consumption in the steel industry when compared with a conventional blast furnace (BF). To obtain parameters on the material flow of these processes, two static process models for TGR-OBF and COREX were established. Combining the operating data from the Jingtang steel plant with established static process models, this research presents a detailed analysis of the material flows, metallurgical gas generation and consumption, electricity consumption and generation, comprehensive energy consumption, and CO2 emissions of three integrated steel plants (ISP) equipped with the BF, TGR-OBF, and COREX, respectively. The results indicated that the energy consumption of an ISP with the TGR-OBF was 16% and 16.5% lower than that of a conventional ISP and an ISP with the COREX. Compared with a conventional ISP, the coking coal consumption in an ISP with the TGR-OBF and an ISP with the COREX were reduced by 39.7% and 100% respectively. With the International Energy Agency factor, the ISP with the TGR-OBF had the lowest net CO2 emissions, which were 10.8% and 35.0% lower than that of a conventional ISP and an ISP with the COREX. With the China Grid factor, the conventional ISP had the lowest net CO2 emissions—2.8% and 24.1% lower than that of an ISP with the TGR-OBF and an ISP with the COREX, respectively.

Analysis of titanium distribution behaviour in vanadium-containing titanomagnetite smelting blast furnace

ABSTRACTThe operating data of a commercial vanadium-containing titanomagnetite smelting blast furnace (BF) have been examined over a period of one year. The liquidus temperatures and viscosities of a large number of slags were calculated by using the software Multi-Phase Equilibrium. The results show that both the slag liquidus temperature and hot metal temperature of the BF were 60 K lower than that of conventional BF operation, while both slags had similar viscosity. The correlations between the Ti distribution of hot metal and slag and the operating temperature, and hot metal and slag chemistry were analysed. Ti distribution ratio increases with increasing temperature and carbon content in hot metal. The Ti distribution calculated based on a slag/hot metal equilibrium model gave reasonably good agreement with plant measurements. This suggests that the slag and hot metal phases were close to equilibrium in the furnace hearth. A sensitivity analysis showed that temperature and C content has a significant influence on the Ti distribution ratio. The effect of slag chemistry on the Ti distribution is insignificant. Lowering of the operating temperature and carbon in hot metal can help reducing the Ti distribution into the hot metal, hence reducing the formation of Ti(C,N).

Physical Modeling Study on the Mixing in the New IronArc Process

IronArc is a newly developed technology for pig iron production with the aim to reduce the CO2 emission and energy consumption, compared to a conventional blast furnace route. In order to understand the fluid flow and stirring in the IronArc reactor, water modeling experiments are performed. Specifically, a down scaled acrylic plastic model of the IronArc pilot plant reactor is used to investigate the mixing phenomena and gas penetration depth in the liquid bath. The mixing time is determined by measuring the conductivity in the bath, after a sodium chloride solution is added. Moreover, the penetration depth is determined by analyzing the pictures obtained during the experimental process by using both a video camera and a high speed camera. The results show that the bath movements are strong and that a circular movement of the surface is present. The mixing in the model for the flow rate of 282 NL min−1 is fast. Specifically, the average mixing times are 7.6 and 10.2 s for a 95% and a 99% homogenization degree, respectively. This is 15% and 18% (per degree of homogenization) faster compared to the case when using 3 gas inlets and the same flow rate.

Investigation of strength and reduction reactivity during heat treatment in simulated-experimental blast furnace of carbon-containing pellet prepared by vapor deposition of tar to cold-bonded pellet with large particle size

Optimum conditions for preparing carbon-containing pellets with a high crushing strength and high reactivity using three kinds of cold-bonded pellets (CPs) prepared by different methods are investigated in this study. The carbon-containing pellets, which have a size fraction suitable for blast furnace are prepared by completely filling the pores in CPs with carbonaceous materials derived from coke oven gas (COG) tar by the vapor deposition (VD) method. A flow-type quartz fixed-bed reactor is used for this method, using a combination of tar pyrolysis at 700 °C and VD at 350 °C. The changing pore size distribution, distribution of the carbonaceous material, and crushing strength of the VD samples are then measured for the prepared composites. The carbonaceous materials derived from COG tar completely fills into the mesopores and macropores of the CPs, which is prepared by using Portland cement (PCB) or Carboxymethyl cellulose (CMC), as the binder, and the aging method in stainless-steel container, with increasing VD treatment time. When PCB is treated by the VD method, the C content and crushing strength tends to increase with increasing VD treatment time, and reached 16 wt%-dry and 45 daN, respectively, until 60 min; these values are comparable to the strength of metallurgical-coke with DI1506 = 87.1. Additionally, carbonaceous materials are uniformly deposited in the particles inside. The changes in the reduction behavior and crushing strength of the prepared VD sample under various heat conditions (simulation-values in experimental-blast furnaces in COURSE50 project). The reduction extent of the VD samples prepared from PCB reaches up to 30–40% at 850 °C. These rates increase above 850 °C and attain a value >95% until 950 °C irrespective of the heating and atmospheric conditions. Fe2O3 and Fe3O4 in the VD samples are reduced to FeO and/or α-Fe until 850 °C under any condition used, while FeO is completely reduced to α-Fe by 950 °C. The cold crushing strength of VD samples is maintained up to 850 °C. Although this value drastically decreases at 900 °C, which is the temperature at which α-Fe formation occurred, there is no decrease in strength for the reduction of Fe2O3 to Fe3O4, which has been observed reduction disintegration occurs in a conventional blast furnace.

Study of the pyrolysis kinetics of Datong coal using a sectioning method

shortage of good-quality coking coal, the COREX process was designed as a new ironmaking technology, attracting wide attention (Fang et al., 2005). In this process, lump coal and a small quantity of coke are directly charged into the melter-gasifier, where a high-quality reducing gas is generated for the reduction of the iron ore (Kumar et al., 2009). In contrast to the conventional blast furnace (BF) process, non-coking lump coal is used as the reducing agent and as the energy source, and the iron charge consists of lump ore and/or pellets, which results in the elimination of the coke oven and sintering plant as well as a decrease in investment (Kumar et al., 2009; Liu et al., 2012). Although the COREX process has made great progress, in current production practice the energy consumption greatly exceeds that of the BF, and it requires a certain amount of coke to maintain permeability of the semi-coke bed (Wang et al., 2008). In addition, the process consumes a lot of good-quality lump ore and lump coal. The pyrolysis of coal is the first step in most coal conversion processes, such as carbonization, gasification, and combustion (Aboyade et al., 2013). The reaction behaviour of lump coals in the COREX melter-gasifier is crucial, as it determines energy utilization and gas composition, as well as the metallurgical properties and particle size of the semi-coke produced (Prachethan et al., 2011; Zhang et al., 2014). In order to optimize the process and improve its competitiveness, the pyrolysis kinetics of Datong coal used in Baosteel’s COREX C-3000 facility was studied. Generally, the Coasts-Redfern method (Xu et al., 2010), ‘model-free’ method (Xu et al., 2010), and DAEM method (Tang et al., 2005) are used to investigate the kinetics of coal pyrolysis. In the Coasts-Redfern method, commonly used mechanism functions are inserted into the non-isothermal kinetic equation to fit the experimental data one-byone. The mechanism function with the largest correlation coefficient is selected as the best (Zhang et al., 2013). In this process, the reaction order is often replaced by the apparent reaction order to obtain the best fit (Zhang et al., 2014). However, the physical and chemical meanings of the reaction model are ignored. In the ‘model-free’ method (or DAEM method), the activation energies under different conversion rates can be calculated. However, there is no way to calculate the kinetic mechanism functions and the related parameters (Xu et al., 2010; Tang et al., 2005). Therefore, based on the previous research, a sectioning method was proposed to study the kinetics of coal pyrolysis. The kinetic parameters at different heating rates were Study of the pyrolysis kinetics of Datong coal using a sectioning method by R. Du*†, K. Wu*†, X. Yuan*†, D. Xu*†, and C. Chao*†

FUNDAMENTAL STUDY OF THE EFFECT OF IRON REDUCTION ON THE BINDER TYPE IN IRON ORE BRIQUETTE

As well known that the Iron and Steel Industry has been priority policy by the Indonesian government in order to meet the requirement of iron and steel in community base. There were made to develop processes for producing iron for steelmaking that could serve as alternatives and/or supplements to the conventional blast furnace in order to produce both of them save energy, low cost, and environmentally friendly. Fundamental study on the effect of the iron reduction on binder type in iron ore briquette was studied by using an electric furnace. In the experiments, three types of samples were used. The iron ore was mixture by using low-grade coal and three kinds of binder for making iron ore briquette. The CO2 and N2 gas based were injected into the reduction as the reducing gas media. The reduction degree properties were expressed in terms of iron ore reduction index (IRI). The iron ore reduction index was determined by the mass change of the sample after reduced with CO2 as gas media. The reduction degree iron in the sample was characterized by using X-ray diffraction (XRD) analysis. The experimental results show that low-grade coal content and binder type are playing an important role in briquette mass reduction. The mass reduction of iron ore briquette composed of 10 % low-grade coal is faster compared to that composed without using low-grade coal. The briquette by using heavy oil as a binder that higher mass reduction is obtained. The component in the sample was dominated by Fe2O3, Fe3O4 and carbon It was shown that iron ore briquette by using asphalt as binder reduced of Fe2O3 into Fe3O4 easily than that using heavy oil and bentonite. Article DOI: https://dx.doi.org/10.20319/mijst.2016.s11.159168 This work is licensed under the Creative Commons Attribution-Non-commercial 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by-nc/4.0/ or send a letter to Creative Commons, PO Box 1866, Mountain View, CA 94042, USA.