Iron Ore Sintering Research Articles

Adaptability analysis of H2-rich gas injection and sintered ore performance with different raw material ratios

As a source substitution technology that reduces pollutants emission and optimizes sinter properties, H2-rich gas injection-assisted iron ore sintering holds significant practical value. This study analyzed the adaptability of this technology to different ore blend ratios and basicity levels by comparing sintering indexes, pore structure, mineral phase composition, and metallurgical performance before and after H2-rich gas injection. The carbon emission reduction following H2-rich gas injection was calculated. The results indicate that increasing the proportion of high-silica, low-alumina ore (Ore-A) and basicity, along with H2-rich gas injection, can effectively enhance sinter yield and quality, but shrink the pore structure of sinter. Under H2-rich gas injection conditions, decreasing Ore-A ratios and increasing basicity can augment SFCA phase formation and mineral phase uniformity, thereby improving the anti-pulverization ability and reductivity of the sinter. H2-rich gas injection presents better adaptability to sintered ore with lower Ore-A ratio and basicity, which can achieve greater improvements in the sintering indexes, RDI, and RI. For a 265 m2 sinter plant producing sinter with 18 wt.% Ore-A and 2.0 basicity, annual CO2 emissions can be reduced by approximately 40,000 t.

Suspension-washcoat optimization for preparing copper-manganese oxide structured catalyst towards flue gas CO purification

Structured catalysts play significant role in nowaday environmental industry. The copper-manganese oxide (Cu-Mn) is a low cost and efficient catalyst for CO purification from flue gas, for which a robust preparation regarding stabilized suspension and washcoat process is still lacked. This work addressed this challenge by constructing the catalyst suspension by introducing absorbent polymer (SAP), polyvinyl alcohol (PVA), and nano-silica sol (SiO2-NA). The effects of the dosage of SAP, PVA, and SiO2-NA on suspension properties including viscosity, water-retention capacity and stability were systematically studied. The combined effect of the three additives regarding electrostatic-sterical stability and regionalized coating is demonstrated to avoids the destruction of connection between SiO2-NA and Cu-Mn due to the thermal stress during the drying process. After calcination, SiO2-NA is efficiently utilized, evenly distributed and tightly bonded to Cu-Mn catalyst, rendering strongly-attached, crack-free and compact washcoated layer. The optimized structured catalyst shows appreciable balance of loading (up to 182kg/m3) and strength (powder shedding rate <1wt%) without blockage. The potential of practical application was verified by CO purification from realistic iron-ore sintering flue gas with catalytic efficiency of above 90% for 240h. These findings indicated a promising strategy to design Cu-Mn structured catalysts efficient for industrial use.

CO Reduction Process Technology and Development of Iron Ore Sintering Process

CO Reduction Process Technology and Development of Iron Ore Sintering Process

Prediction of SO2, NOx and PM in the sintering process based on deep learning

The accurate prediction of SO2, NOx and PM emissions in the iron ore sintering process could adjust the desulfurization and denitrification operation in time. The study presented an integrated prediction model for SO2, NOx and PM in sintering flue gas. Gradient boosting decision tree, recurrent neural network, gated recurrent unit were chosen as sub-models to predict SO2, NOx and PM by comparing different regression prediction models, which were then combined to form an integrated prediction model (MMEP). The box plots, empirical mode decomposition algorithm, Pearson correlation coefficient and maximum information coefficient to select independent variables for the predictive model. The MMEP model had an overall accuracy greater than 0.82, as verified by production data, which could provide guidance for on-site sintering production.

Coke breeze combustion and emission behaviors of CO and NO during iron ore sintering

CO emission reduction, especially the coordinated emission reduction of CO and NO in sintering flue gas, has attracted widespread attention in the world. The effects of different sintering raw materials, temperature and atmosphere on coke breeze combustion and CO and NO emission behaviors were studied. The results show that, sintering raw materials significantly improved the combustion performance of coke breeze, and promoted the simultaneous reduction of CO and NO emissions. Among them, Dolomite had the strongest catalytic effect, which reduced the apparent activation energy of coke breeze combustion reaction from 99.35 kJ/mol to 56.11 kJ/mol, and the emission reductions of CO and NO were as high as 47.84 % and 73.25 %, respectively. The catalytic ability of the raw materials components was CaO ＞ MgO ＞ Fe2O3. However, during the combustion process of coke breeze without raw materials, the reduction of NO by CO was affected by the atmosphere of the boundary layer, the conversion of N element was negatively correlated with the content of CO. When the temperature increased from 600 ℃ to 1 050 ℃, the combustion performance was improved, the thickness of the combustion zone was reduced by 47.92 %, the total emission of CO was decreased by 65.39 %, and the total emission of NO was increased by 23.05 %. The O2 concentration decreased from 21 % to 10 %, the combustion rate decreased, the combustion zone thickened by 90 %, incomplete combustion was promoted, the total emission of CO increased by 101.15 %, and NO decreased by 21.09 %. The CO2 concentration increased from 5 % to 15 %, the gasification reaction was enhanced, the combustion time was extended, the combustion zone thickened by 45.9 %, the total emission of CO increased by 87.12 %, and the reducing atmosphere was enhanced, which was conductive to the reduction of NO by CO, and the total emission of NO decreased by 50.59 %.

Calcined colemanite as an additive for iron ore sintering process

During sintering process, iron ores, fluxes and coke are agglomerated into a desirable blast furnace feed. The degrading iron ore quality and environmental norms has forced sinter producers to look for additives which can improve the sintering process efficiency. For the current work, use of calcined colemanite as an additive was studied by adding it from 0% to 4% within the sinter raw blend through lab-scale pot trials. During the sintering process, calcined colemanite forms a Calcium Borosilicate (Ca11B2Si4O22) phase at temperature above 400 °C which latter gets dissociated within the liquid melt thus increasing the liquid slag formation. Increasing calcined colemanite up to 2% increases tumbler index from 56.27% to 61.67%, decreasing thereafter to 55.33% at 4% of calcined colemanite. The sinter yield (+5 mm) is also found to be maximum of 89.39% at 2% of calcined colemanite. An increase in calcined colemanite from 0% to 4% increases sintering time from 20 to 26 min, decreasing the overall sinter productivity from 2.35 to 1.99 t/m2/h. Before integrating calcined colemanite within the sintering process at plant scale, its cost and efficacy must be considered. An alternate approach can be combining it with an organic binder where the two can complement each other in providing the required sinter properties.

Modelling breakage of steelmaking materials for simulation of mechanical degradation during handling

Mechanical degradation of steelmaking materials can have significant economic and environmental implications. Such degradation typically occurs as result of impacts during transportation and handling from their production site to the steelmaking furnace, in operations that include transfers in chutes, ship loading, stockpiling, reclaiming, wagon loading and discharging, etc. Predicting the extent of such degradation and attempting to prevent it, is worthwhile. Fortunately, mechanical degradation during such operations can now be predicted using different approaches, but a proper breakage model is required. The work presents results from single-particle breakage tests of iron ore lump, sinter, briquette, and pellet samples, besides coke, followed by fitting parameters of the Tavares UFRJ Breakage Model. These are then used to simulate degradation in a hypothetical handling circuit. Predictions demonstrate the high susceptibility of iron ore lump and briquette to fines generation, when compared to the other materials, and the occurrence of conditioning for briquettes and sinter, which is the increase in strength of particles surviving handling. Iron ore pellets and coke remained comparatively unaffected by the handling operations simulated, which is explained by their greater resistance to either body or surface breakage.

Mathematical modeling and characteristics evaluation of coke replacing with commercial biochar in iron ore sintering process

For green production of iron ore sintering, the research on replacing traditional coke with clean energy such as biochar is a new hot topic. Most of the work conducted in biomass fuel utilization in sintering is done on a laboratory or pilot-scale. Little work was reported by using mathematical models to predict the influence of biomass-based fuel replacement on sintering performance quantitatively. In this paper, a more comprehensive numerical model that incorporates most of the significant reaction processes and heat transfer modes was proposed first, especially with considerations of coke/biochardual-fuelphase heat supply and their pyrolysis, volatiles release, and combustion processes. Experimental data of the sintering pot reasonably agreed with the numerical results, which validated the model. Based on the equivalent fixed carbon method, the combustion and sintering behaviors in replacing proportions, particle size, and fuel types of commercial biochar for coke in the sintering bed were compared. With the lower replacement proportions (<20 %), both two biochars (Oak and Pine) can ensure thermal state indicators (PT, RT, MQI, CR) and combustion performance indicators (FFS and combustion efficiency), and keep the yield enough high. When the replacement proportion exceeds 50 %, the sintering index is worsened significantly. The emission of NOx can be decreased by 57.62 % when a 100 % replacement proportion of biochar is used. The results also indicate that coarsening particle size (2.4 mm was recommended for use) can further improve sintering indicators, and make Oak char 50 % replacing proportion reach the level of all coke method. The performance of pine sintering is even better than Oak sintering. The multiphase multicomponent model is used to give a mechanism explanation for the behavior and performance of biochar replacing coke in the sintering process.

Reduction of carbon emission in iron sintering process based on hot air sintering technology

Reducing carbon dioxide (CO2) emissions in the iron and steel industry plays a crucial role in addressing global climate change. One significant technological solution for reducing CO2 emissions in iron and steel production is the recycling of waste heat. Hot air sintering has the potential to decrease CO2 emissions from flue gas by reusing hot flue gas in the production process. This can result in a reduction in the consumption of fossil fuels. Usually, the relationship between the hot air temperature and the carbon content determines the CO2 emission reduction effect. In order to meet the demand for reducing CO2 emissions, this paper thoroughly investigates the mechanism of CO2 reduction by hot air sintering through sintering pot experiments. It precisely establishes the correlation between hot air temperature and carbon content, and suggests strategies for effectively managing hot air sintering based on scientific principles. The results show that hot air sintering achieves a reduction in CO2 emissions by enhancing fuel combustion heat utilization and heat substitution. On the one hand, the heat of the sinter bed surface layer is increased, which improves the mineralization conditions and increases the sintered mineral quantity and quality, thus reducing the CO2 emission by 4.4%; on the other hand, the waste heat is returned to the sinter bed to replace part of the fuel combustion heat, thus reducing the CO2 emission by 17.7%. The experimental results show that the best carbon reduction effect is achieved at a hot air temperature of 300 °C and a solid fuel ratio of 4.7% (labelled T300-C47), which reduces carbon emissions by 17.7% and improves the quality of the sintered minerals. Combined with the actual production, in the range of 200–300 °C hot air, by increasing the hot air temperature to replace the solid fuel with equal heat can realize the hot air sintering to reduce CO2 emissions and improve the sintering production. The research provides theoretical guidance for the clean production of iron and steel sintering and energy saving and carbon reduction.

Effect of Electroplating Sludge on the Iron Ore Sintering: Mineralization, Yield and Gaseous Emission

Electroplating sludge (ES), the inevitable by‐product of electroplating wastewater treatment processes, has been conventionally managed via solidification landfilling or thermal processing; these methods may engender secondary environmental pollutants. This study proposes an innovative approach using iron ore sintering for effective ES treatment. The study reveals that incorporating 1.0% ES reduces the yield quality of the sintered ore, yet it remains within acceptable thresholds. It is noteworthy that when the addition of ES is 0.5%, it not only increases the sinter yield from 68.57% to 69.23% but also enhances the productivity from 1.19 to 1.32 t (m2 h)−1. Furthermore, the consumption of solid fuel decreases to 48.01 kg t−1. Additionally, the treatment method significantly reduced the emissions of CO and NOx in the sintering flue gas, with the average concentrations decreasing from 12681.32 to 9744.51 ppm for CO and from 244.81 to 161.11 ppm for NOx. This study investigates the migration and transformation mechanisms of nickel and chlorine elements in ES by conducting inductively coupled plasma analysis on the sintered raw materials and their products, as well as scanning electron microscopy with energy dispersive X‐ray spectroscopy analysis on the sinter ash.

Numerical simulation of the Co-combustion of coke and biochar coupled with methane injection in iron ore sintering processes

It is of great significance for cleaner production to partially replace traditional coke with biomass fuel in iron ore sintering processes. However, the higher reactivity of biomass leads to an unacceptable deterioration in sintering performance, which limits its high proportion application. This paper presents the numerical simulation of the technology of combining gaseous fuels and biomass for iron ore sintering. The improvement effect and mechanism of the methane injection method on the heat pattern and performance of the coke/biochar co-sintering bed were discussed. To more accurately quantify the coupling phenomena involved, the proposed model especially considers sub-processes of biomass combustion and gaseous reactions including volatile release/char formation, burning of the volatiles, and the oxidation and gasification of char particles. The results indicated that the equivalent methane heat injection method reached its limit of improvement at a concentration of about 0.6%, and failed to obtain qualified products. The thermal indicators and yield kept increasing within the concentration simulation range of 0∼0.8% under the extra methane method. At a concentration of 0.8%, peak temperature (PT), duration time (DTMZ), and enclosed area (MQI) in the high-temperature zone are 1442.094 K, 165.6 s, and 15923.72 K s, respectively, reaching the level of all coke method. The use of local concentration segregation can significantly optimize heat distribution and increase the yield of the coke/biochar co-sintering process.

Application of coalbed methane assisted iron ore sintering: Injection effect, pollutant abatement and economic evaluation

Hydrogen-rich gas injection, which has garnered widespread attention from academia and industry, is an effective method for reducing CO2 emissions during the sintering process and for improving sinter quality. Coalbed methane (CBM) is a cost-effective and reliable hydrogen-rich gas resource in China. In this study, we investigated the injection effect of CBM in assisting iron ore sintering. Additionally, we determined the appropriate injection parameters by systematic sintering pot tests and compared it with coke oven gas (COG). The impacts of CBM injection on pollutant abatement and combustion efficiency were analyzed based on the variations in the sintering flue gas composition, and a comprehensive economic evaluation was conducted. The results showed that injecting 0.51 vol% CBM between 5 and 13 min after ignition with 0.3 wt% coke breeze ratio reduction could significantly improve the sintering index and the uniformity of heat distribution within the sinter bed. Excessive injection would affect the bed permeability. CBM took advantage over COG at a gas–solid heat transfer ratio of 1:1.28. The four-stage cascade mode with a gradient of 0.18 vol% and the intermittent mode with an intermittent time of 0.5 min could optimize the injection effect. However, the cascade mode performed better. Besides, injecting CBM increased the emission reduction rates of CO and NOx and improved combustion efficiency by 5.72%, 4.47%, and 1.46%, respectively. Overall, the cost-savings were CNY 2.19 per ton sinter, and the annual production cost could be reduced by approximately CNY 6.71 million for a 265 m2 sintering machine. The profits achieved because of CBM injection can be further improved by increasing the bed permeability and mixed injecting with other gas media. This study provides an effective path for green transformation of sintering production.

Influence of ammonia and Brown gas injection on the iron ore sintering characteristics under biochar substitution

The influence of ammonia and Brown gas injection on the iron ore sintering characteristics was explored through sintering pot experiments based on biochar substitution to increase biochar substitution proportion and reduce fossil energy consumption. By dividing the high-temperature stage of the sintering bed, the heating rate and cooling rate were calculated, and the reasons for poor sintering quality under a high biochar substitution ratio were explored. The results showed that under the 40% biochar substitution ratio, the cooling rate of the sintering bed significantly increased, the high-temperature duration time was short, and the sintering quality deteriorated severely. Additional injection of 0.5–1% vol ammonia or 1–2% vol Brown gas can reduce the cooling rate, prolong the high-temperature duration, and optimize the sintering quality. Based on 1% vol ammonia or 2% vol Brown gas injection, reducing the proportion of biochar with equal calorific value further increases the sintering comprehensive index, which means that using 1% vol ammonia or 2% vol Brown gas injection to assist sintering can reduce the proportion of coke usage to 60%, while the proportion of biochar substitution is 33.76% and 32.47%, respectively. The research results provide an effective solution for low-carbon sintering.

Characterisation of iron ore sinter products with varying binary basicity (CaO/SiO2) from 1.5 to 2.7

Characterisation of iron ore sinter products with varying binary basicity (CaO/SiO₂) from 1.5 to 2.7

Industrial waste and biomass charcoal composite fuel for iron ore sintering: harmless disposal of waste and carbon reduction

Industrial waste and biomass charcoal composite fuel for iron ore sintering: harmless disposal of waste and carbon reduction

Inhibition Mechanism of H2O on CO Oxidation Over CeMnOx Catalyst in Iron Ore Sintering Flue Gas

Inhibition Mechanism of H2O on CO Oxidation Over CeMnOx Catalyst in Iron Ore Sintering Flue Gas

Emission characteristics and control technology of heavy metals during collaborative treatment of municipal solid waste incineration fly ash in iron ore sintering process

Emission characteristics and control technology of heavy metals during collaborative treatment of municipal solid waste incineration fly ash in iron ore sintering process

An adaptive control system based on spatial–temporal graph convolutional and disentangled baseline-volatility prediction of bellows temperature for iron ore sintering process

The temperature within the sintering furnace is a decisive factor influencing the quality of the sintered ore in the iron ore sintering process. In practical operations, the temperature at the bellows directly linked to the bed layer indirectly signifies the internal furnace temperature. Maintaining a stable temperature at the bellows, particularly at the burn-through point, is vital for minimizing gas emissions, improving carbon efficiency, and enhancing the quality of the sintered ore. This paper proposes an intelligent temperature control system based on Spatial–Temporal Graph Convolutional and Disentangled Baseline-Volatility (STGCDBV) prediction. The STGCDBV network comprises three parallel modules: Adaptive Graph Convolution Network (AGCN), Baseline and Volatility Disentangler (BVD), and a residual link, along with a Temporal–Nodal Encoder–Decoder (TNED) module. The AGCN constructs a graph reflecting the characteristics of bellows temperature, effectively merging static spatial data with dynamic thermal information. The BVD module captures the nonlinear trend data inherent in the sintering process. In contrast, the TNED synergizes the insights from the parallel modules using cross encoding and decoding functionalities. For controlling the sintering gas flow rate, a Model Reference Adaptive Control (MRAC) system is implemented, which utilizes a control scheme founded on a temperature reference model and iterative parameter adjustments. Extensive experiments using actual time-series data from a steel plant have been conducted. Moreover, comparisons between the performance of pre- and post-control interventions demonstrate that the STGCDBV-MRAC system can stabilize temperature fluctuations and exhibit exemplary control proficiency.

Potential and Environmental Benefits of Biochar Utilization for Coal/Coke Substitution in the Steel Industry

The metallurgical sector is one of the most emission- and energy-intensive industries. The possibility of using fossil carbon substitutes has been investigated to reduce the environmental impact of the steelmaking sector. Among others, biochar emerged as a promising fossil coal/coke substitute. We conducted a literature review on biochar use in the metallurgical sector and its potential environmental benefits. The possibility for biochar as a coal/coke substitute is influenced by the source of biochar production and the process within which it can be used. In general, it has been observed that substitution of biochar ranging from a minimum of 5% to a maximum of 50% (mostly around 20–25%) is possible without affecting, or in some cases improving, the process, in coke making, iron sintering, blast furnaces and electric furnaces application. In some studies, the potential CO2 reduction due to biochar use was estimated, ranging from 5% to about 50%. Despite there still being an area of further investigation, biochar appeared as a promising resource with a variety of uses in the metallurgical sector, contributing to the lowering of the environmental impact of the sector.

VOCs (toluene) removal from iron ore sintering flue gas via LaBO3 (B = Cu, Fe, Cr, Mn, Co) perovskite catalysts: experiment and mechanism

Abstract The challenges posed by volatile organic compound (VOC) emissions in iron ore sintering flue gas are significant. La-based perovskite catalysts offer a promising solution for efficiently degrading VOCs. In this study, a series of LaBO3 (B = Cu, Fe, Cr, Mn, Co) perovskite catalysts were synthesized using the sol-gel method. The influence of various B-site elements on the catalyst’s structure and surface chemical properties was thoroughly examined. Simulations were conducted to assess the VOC reduction capabilities of these catalysts under conditions mimicking sintering flue gas composition. It was found that the crystallite size of the perovskite catalyst decreases as the ionic radius of the B-site elements increases, while the specific surface area, total pore volume, and average pore size increase correspondingly. Notably, LaCoO3 and LaMnO3 demonstrated exceptional activity, attributed primarily to their elevated surface oxygen concentration and oxygen migration capability, positioning them as highly promising materials for further development. Furthermore, a proposed mechanism elucidates the La-based perovskite catalytic reduction of toluene, wherein lattice oxygen and adsorbed oxygen undergo mutual conversion during the oxidation process. This mechanism aligns with the L-H and M-v-K models, providing a comprehensive understanding of the catalytic process.