Sinter Production Research Articles

Process development for reduction of NOx emission in sinter making

Laboratory pot grate sintering studies have been carried out to explore the NOx emission during coke combustion in the presence and absence of quick lime and quick lime with iron ore fines as coating material on coke breeze (LCCB & LICCB). Melt formation studies have been carried out to know the melt formation at different temperatures. The pot grate sinter test results showed that quick lime and quick lime with iron ore fines were catalytically active in promoting coke combustion and reduction in NOx emission and improving the sinter productivity & sinter properties. In sintering experiments sinter productivity, sinter strength and NOx reduction, improved with quick lime (LCCB: 0.49%) and quick lime with iron ore fines (LICCB: 0.49 + 0.49%) as coating material on coke breeze (LICCB). With increase in quick lime and quick lime with iron ore fines as adhering layer on coke breeze the wind box temperature increased up to 0.49% due to increase in coke combustion rate with the help of formed CaO.Fe2O3 melt layer and decreased the overall NOx emission by decreasing the oxygen concentration in gas film at the surface of the coke breeze. The effect was not significant with the addition of quick lime and quick lime with iron ore fines >0.49%. Calcium ferrite suppressed the formation of NOx. As the NOx emission decreases the oxygen concentration in the gas also decreased. From sintering experiments, it was found that −3 mm coke breeze is effective for reducing the NOx emission with LCCB and LICCB compared to −1 mm coke breeze. The finer size coke is considered to be difficult to reach higher temperatures of combustion. Through LCCB and LICCB decrease in NOx emission was 37% and 49% respectively. Coating with quick lime & iron ore fines on coke breeze as adhering material is the one of the effective methods to reduce the NOx emission compared to quick lime coating on coke breeze.

Геоэкологическая оценка загрязнения окружающей среды по биогеохимическим параметрам древесных растений (на примере г. Липецка)

To conduct a geoecological assessment of the territory of the Lipetsk city, biogeochemical parameters of woody plants were used. Populus italica (Du Roi) Moench, growing in different ecological conditions, acted as an indicator species. Sampling of poplar bark was carried out at 21 points, including the background one. The laboratory determined the following biogeochemical parameters: acidity, ash content, content of chemical elements. During the summer period 2022– 2023 samples were taken and analyzed. According to the data obtained, the pH of the aqueous extract of the samples varied from 5.05 to 7.74 for different sampling points, the average value being 6.98. We have established a change in the hydrogen index of the Italian poplar bark towards alkalization. The maximum increase in pH was recorded in the area of the cement plant (7.74), as well as on the left bank, where Novolipetsk metallurgical plant production facilities are concentrated. The lowest indicator of acidity of the crust is typical for the recreational zone of park areas – 5.05. The ash content of Italian poplar peel in the territory of Lipetsk varied from 10.42 to 21.44%. We noted the minimum ash content in the Nizhny Park, the maximum parameter was recorded in the immediate vicinity of the Novolipetsk metallurgical plant production sites and in the zone of influence of the cement plant. Determining the amount of chemical elements in the Populus italica bark by the X-ray fluorescence method made it possible to establish a number of regularities. The selected samples have a high level of accumulation for a number of heavy metals. Copper was found at 11 points. In terms of manganese, the highest content was recorded in a sample of Italian poplar bark on the street. Diamond (330 mg/kg). At all points, with the exception of the Nizhniy park, there is an excess of background values. The concentration of zinc in almost all samples is high, more than 80 mg/kg, especially trees in the industrial and transport zone have elevated values of the indicator. The content of iron at all points in the territory of Lipetsk exceeds the background values (1.04 g/kg). The presence and high content of a number of chemical elements in the Italian poplar bark is explained by the fact that in addition to carbon, sulfur, nitrogen oxides, the composition of emissions from blastfurnace, sintering production, ferroalloys includes a large amount of dust containing particles of Fe, Сu, Ti, Zn, Pb, Cr and other heavy metals. A moderate correlation was established between the content of iron-titanium (r±mr=0.48±0.20) and iron-zinc (r±mr=0.47±0.20) in the Italian poplar bark. A high level correlation was recorded between the concentrations of iron and manganese (r±mr=0.80±0.14). Therefore, the use of tree bark to assess environmental pollution is a sensitive method that is used for geoecological monitoring.

Design of Inorganic Polymer Composites for Electromagnetic Radiation Absorption Using Potassium Titanates

This paper investigated the synthesis of inorganic polymer composites for electromagnetic radiation absorption using potassium titanates. The selected polyamide 6 and potassium polytitanate materials contain TiО2, K2СО3, and KCl obtained by charge sintering. Results showed that modification of polyamide 6 with sintering products in the form of a fine powder of potassium polytitanate that contains different phases K2O × 2TiO2, K2O × 4TiO2, and K2O × 6TiO2 which increased their strength properties. With increased potassium titanates (PTT) synthesis, a gradual transition from di to potassium hexatitanates occurs K2O × 2TiO2 – K2O × 4TiO2 – K2O × 6TiO2. The optimal content of potassium polytitanate was over 20 % by mass. To fully ensure the reinforcing effect due to the filling of potassium polytitanate polyamide 6, it is necessary to use whiskers K2O × 6TiO2, which can be collected by the additional crystallization of the amorphous charge sintering product. By designing experimental-statistical mathematical models in equal regressions, mathematical optimization of inorganic polymer composites for electromagnetic radiation absorption using PTT was carried out.

Measures to modernize the sintering department of the sinter plant of PJSC “KAMET-STEEL”

When producing sinter in the conditions of Ukrainian metallurgical enterprises, it is expedient to use domestic raw materials and try to increase the productivity of sintering shops to global indexes in the range of 5 to 7 million tons/year of sinter. At the same time, the following requirements should be made to the quality of sinter: the highest iron content, the minimum amount of harmful impurities, the stability of the chemical and granulometric compositions, high reducibility and gas permeability, high strength and low content of the fraction less than 5 mm. To increase the competitiveness of sinter production, the following means should be used: construction of sinter plants of a new generation with modern sintering machines; carrying out major repairs and modernization of fixed assets of sinter production; application of energy-saving technologies of sintering et al. The paper proposes measures to modernize the industrial department of sinter plant No. 2 of PJSC “KAMET-STEEL”. To modernize sintering machine No. 7, it is proposed to repair longitudinal and transverse seals of the sintering machine, gas collector, vacuum chambers, dust bags, compensators in the sintering zone, vacuum chambers in the cooling zone, the recovery of thermal insulation on the gas collector, vacuum chambers, and dust bags. The proposed measures make it possible to reduce electricity consumption at the sinter plant, increase the productivity of sintering machine No. 7 to 933.372 tons/year of sinter, reduce the content of fines in the sinter to 8 %, reduce the consumption of solid fuel to 20 %, and increase the service life of the equipment (exhauster rotors and pallet carts with grates).

ОПТИМИЗАЦИЯ ТРАНСПОРТНОГО ОБСЛУЖИВАНИЯ АГЛОМЕРАЦИОННОГО ПРОИЗВОДСТВА С УЧЕТОМ ДИНАМИКИ ПОТОКОВ

The paper considers features of transport service of sinter production with the consideration for traffic dynamics. Over a long period of time during which the problem hadn’t been studied, the enterprise faced serious technological transformations. Intensification of production processes set new tasks for industrial transport. The task consisted in creation of a mathematical model of a production and transport system for optimization of operation of sinter production with raw materials traffic. The mathematical model is based on a dynamic transportation problem with delays.

Elevated levels of chloramines and chlorine detected near an indoor sports complex.

Chloramines (NH2Cl, NHCl2, and NCl3) are toxic compounds that can be created during the use of bleach-based disinfectants that contain hypochlorous acid (HOCl) and the hypochlorite ion (OCl-) as their active ingredients. Chloramines can then readily transfer from the aqueous-phase to the gas-phase. Atmospheric chemical ionization mass spectrometry using iodide adduct chemistry (I-CIMS) made observations across two periods (2014 and 2016) at an urban background site on the University of Leicester campus (Leicester, UK). Both monochloramine (NH2Cl) and molecular chlorine (Cl2) were detected and positively identified from calibrated mass spectra during both sampling periods and to our knowledge, this is the first detection of NH2Cl outdoors. Mixing ratios of NH2Cl reached up to 2.2 and 4.0 parts per billion by volume (ppbv), with median mixing ratios of 30 and 120 parts per trillion by volume (pptv) during the 2014 and 2016 sampling periods, respectively. Levels of Cl2 were observed to reach up to 220 and 320 pptv. Analysis of the NH2Cl and Cl2 data pointed to the same local source, a nearby indoor sports complex with a swimming pool and a cleaning product storage shed. No appreciable levels of NHCl2 and NCl3 were observed outdoors, suggesting the indoor pool was not likely to be the primary source of the observed ambient chloramines, as prior measurements made in indoor pool atmospheres indicate that NCl3 would be expected to dominate. Instead, these observations point to indoor cleaning and/or cleaning product emissions as the probable source of NH2Cl and Cl2 where the measured levels provide indirect evidence for substantial amounts transported from indoors to outdoors. Our upper estimate for total NH2Cl emissions from the University of Leicester indoor sports complexes scaled for similar sports complexes across the UK is 3.4 × 105 ± 1.1 × 105 μg h-1 and 0.0017 ± 0.00034 Gg yr-1, respectively. The Cl-equivalent emissions in HCl are only an order of magnitude less to those from hazardous waste incineration and iron and steel sinter production in the UK National Atmospheric Emissions Inventory (NAEI).

Determination of rational parameters of agglomeration of Suroyam deposit`s titanomagnetite ores

Technological parameters for the production of sinter from titanomagnetite ores of the Suroyam deposit in the Chelyabinsk region have been developed. For this, concentrates with a content of up to 63.3 % Fe were obtained from experimental batches of ores, and agglomerates were obtained from them. The studies were carried out in order to increase the reliability and visibility of the results of agglomeration by comparing the Suroyam concentrate with an analogue concentrate that has an industrial implementation. The optimal moisture content of the charge, including the Suroyam deposit`s concentrate, was 8%. At a given charge moisture content, carbon content of 4.5 % and basicity of 1.6, the specific productivity of the sinter plant was 1.089 t/(m2∙h), which is 3.8 % more when sintering the charge with a moisture content of 7.5 % and 29.2 % more when sintering the charge with a moisture content of 8.5 %. With a basicity in the range of 1.6–1.8, a charge moisture content of 8 %, and a carbon content of 4.5 %, the yield of suitable sinter averaged 80.0 %, and the specific productivity was 1.100 t/(m2∙h). The quality indicators of the agglomerate are as follows, %: impact resistance 70.1; destruction 25.3; abrasion 5.1. With a basicity of 1.8, the yield of suitable sinter according to the +5 mm class and the specific productivity were 92.6 % and 1.641 t/(m2∙h), respectively, which is 0.9 and 3.41 % (rel.) higher than the figures obtained when sintering an agglomerate with similar parameters from an analogue concentrate having an industrial implementation.The article was prepared with the support of the grant of the President of the Russian Federation No. MD-1064.2022.4.

Influence of iron ore properties on dioxin emissions during iron ore sintering

Iron ores are principal input materials for iron and steel-making industries. Quality of iron ores is one of the critical parameters for formation of environmental pollutants related to the steel-making process. Dioxins are identified as one of the most toxic pollutants emitted during ironmaking, specifically during the sintering process. This study applied four types of iron ores and analyzed their moisture, density, particle size distribution and element concentrations to investigate their effect on the dioxin formation during sintering. Each type of iron ore was processed in a sinter pot grate. During each processing route, exhausted dust and generated sinter products were collected and subjected to PCDD/F and PCB analysis. Statistical analysis was applied to assess correlations between properties of iron ores and exhausted dioxin emissions, identifying key contributors to dioxin formation during sintering process. Results showed that Fe in iron ores was positively and significantly related to PCB 114 formation in dust and confirmed its co-catalytic effect on dioxin formation. Concentrations of Al, Ti and Cl in iron ores greatly increased PCDD/F and PCB emissions in the sintered products compared to dioxins in dust samples. The S levels and density of iron ores were highly related to the increasing PCDD/F and PCB emissions in both sinter and dust samples. By contrast, concentrations of Si in iron ores played a significant role in decreasing PCDD/F and PCB emissions in both sinter and dust samples. This study also confirmed the optimum size (< 1 mm–2.59 mm) for iron ores, which helps reduce dioxin emissions without affecting the quality of iron and steel-making products.

GAS DYNAMIC ANALYSIS OF THE SINTER CHARGE IGNITION PROCESS

To increase the productivity of sintering machines, sinter quality and economy of the gaseous fuel, it is necessary to ensure the optimal mode of external heating of sintering charge layer. The effect of sintering machine vacuum chamber throttling under the ignition hearth on the gas-dynamic mode of charge ignition and sintering, including the quality of sinter, sintering machine productivity, gas consumption for the charge ignition and the possibility to control and manage the charge humidity were considered. It is shown, that throttling of the first vacuum chambers allows reduction in the fuel consumption, charge shrinkage, amount of air suction into the ignition hearth and gas-discharge duct of the sintering machine and improvement of the sinter quality. The effects of air rarefaction on charge layer surface temperature and sinter quality are provided. The structural variants of vacuum chamber throttling implemented in practice are presented; two of them operate at sintering machines at Bhilai Iron and Steel Works, India. It is shown that throttling of the first vacuum chambers located under ignition hearth is effective for charge ignition and sintering processes in all cases and should be obligatory during the sinter production.

Improvement of Sinter Productivity and Qualities by Placing Low Slag Green Pellet at Lower Layer of Sinter Packed Bed

Improvement of Sinter Productivity and Qualities by Placing Low Slag Green Pellet at Lower Layer of Sinter Packed Bed

Interface regulation mechanism of Ti doping on B4C/Al composites

The present work adopts a combination of theoretical calculation and experiment. Firstly, the Gibbs free energy enthalpy change of Ti doped B4C/Al composites is calculated by thermodynamic principle, revealing the principle that Ti will preferentially combine with Al and B4C to form TiB2 with excellent performance. Secondly, with the help of spark plasma sintering (SPS) process, pure Al and 4 vol%Ti–Al was used to discuss the degree of interfacial reaction and diffusion between Al–B4C and Ti/Al–B4C. It is found that the addition of Ti effectively inhibits the interfacial reaction between Al–B4C. The kinetic equation of Al diffusion distance and holding time is lnd = 0.66lnt+0.24. Finally, the phase and mechanical properties of two groups of B4C/Al–Ti and B4C/Al composites were analyzed. The results showed that the impurity phase of sintering products of Ti doped samples was greatly reduced compared with that of the non doped group, and the mechanical properties were also significantly improved. Ti doping effectively regulates the interfacial reaction of B4C/Al composites, inhibits the formation of impurity brittle phase in the system, and optimizes the mechanical properties of the composites.

Production of pre-reduced sinter based on sensible heat updraft of sinter

Utilization of pre-reduction burden in the blast furnace ironmaking process is an important measure for realizing low-carbon operation. In this paper, a new process for the production of pre-reduced sinter based on sensible heat updraft of sinter was put forward. The effects of sinter temperature and reducing gas composition in the pre-reduction cooling section on metallization rate and sieve size distribution of pre-reduction sinter were studied. The results showed that the metallization rate and proportion of 10–12.5 mm particle size of pre-reduction sinter increase with the increase of sinter temperature. When the sintering temperature was 950 °C and the reducing gas was the mixture of H 2 and CO, the metallization rate of the pre-reduced sinter was up to 35.5%. When the sintering temperature was lower than 750 °C, the carbon deposition reaction between H 2 and CO reduces the proportion of 10–12.5 mm particle size of the pre-reduced sinter significantly. The metallurgical properties of pre-reduced sinter with different roasting systems under hydrogen-rich smelting in blast furnace were studied. The results showed that compared to the traditional sinter, the reduction degradation index, reducibility index, and softening-melting properties of pre-reduced sinter were improved, and the permeability and maximum differential pressure of the stock column were reduced, which was beneficial to the improvement of blast furnace production efficiency. Based on the comprehensive effects of sinter temperature and reducing gas composition on the metallization rate, sieve size distribution, and metallurgical properties of pre-reduced sinter, the quality of the pre-reduced sinter was better when the sintering temperature was higher than 750 °C and the reducing gas was a mixture of H 2 and CO. In addition, the new process could organically combine sinter sensible heat utilization, flue gas circulation, and denitrification to form a complete technological process, which had a good development prospect. • Production of pre-reduced sinter based on sensible heat of sinter was proposed. • Metallurgical properties of pre-reduction sinter were systematically studied. • The process can organically combine with flue gas circulation and denitrification. • Process route of production of pre-reduced sinter was schematically mapped.

A method for increasing the agglomerate strength by improving the charge pelletization

Since 2016 to the present, JSC Tulachermet has been systematically working to improve the quality of the iron ore part of the blast-furnace charge, which consists of at least 75% of the sinter of its own production. Within the framework of the article, research work was carried out on the selection and application of a line of technological additives for preparing sinter charge for sintering. The article describes the experience of using polymeric binders in laboratory and industrial conditions of sinter production, presents the results of the influence of various organizational and technical measures on the performance of sintering and blast furnace processes of JSC Tulachermet.

Automatic Ore Blending Optimization Algorithm for Sintering Based on the Cartesian Product

In actual sinter production, batching is a complex metallurgical and mathematical problem. Aiming at the problem of the precising batching of iron ore in the process of sintering batching, an automatic batching algorithm based on a Cartesian product to batch sinter was proposed for the first time. When the algorithm is applied to the sintering batching process, a complete batching scheme can be obtained, which can realize the organic combination with other calculation processes, can effectively save the manpower and material cost of sintering batching, and is of great significance to the comprehensive use of iron ore resources. Taking the actual sintering production batching of a domestic iron and steel plant as an example, according to the batching requirements compared with various ore batching schemes, combined with the actual production situation, the automatic batching optimization algorithm based on a Cartesian product is applied to build a mathematical model of sintering batching. Through the algorithm test, the practicability of the automatic batching algorithm is verified. In addition, the automatic batching algorithm based on a Cartesian product has good performance in other batching fields.

Microwave Fast Sintering Production of Sustainable Lightweight Aggregates with Agroindustrial Waste

Microwave Fast Sintering Production of Sustainable Lightweight Aggregates with Agroindustrial Waste

Effect of Granule’s Moisture on Granulation Rate of Iron Ore

For countermeasures of deterioration in iron ore, development of pretreatment technology for high quality iron ore fine is critical issue in the sintering process. However with increasing small particles, sinter productivity is decreased by lower permeability due to increment of un-granulated particles or considerably large granules. Therefore understanding of granulation phenomena becomes more important issue. Since moisture of iron ore largely relates to the granulation behavior, it is necessary to reveal the effect of moisture on granulation rate for controlling the process. In this study, granulation tests were performed and the size distribution of granule was analyzed with probability model and new model considering granulation rate. Based on the calculation results, the effect of moisture on granulation rate was discussed.

SCORN: Sinter Composition Optimization with Regressive Convolutional Neural Network

Sinter composition optimization is an important process of iron and steel companies. To increase companies’ profits, they often rely on innovative technology or the workers’ operating experience to improve final productions. However, the former is costly because of patents, and the latter is error-prone. In addition, traditional linear programming optimization methods of sinter compositions are inefficient in the face of large-scale problems and complex nonlinear problems. In this paper, we are the first to propose a regressive convolutional neural network (RCNN) approach for the sinter composition optimization (SCORN). Our SCORN is a single input and multiple outputs regression model. Sinter plant production is used as the input of the SCORN model, and the outputs are the optimized sintering compositions. The SCORN model can predict the optimal sintering compositions to reduce the input of raw materials consumption to save costs and increase profits. By constructing a new neural network structure, the RCNN model is trained to increase its feature extraction capability for sintering production. The SCORN model has a better performance compared with several regressive approaches. The practical application of this predictive model can not only formulate corresponding production plans without feeding materials but also give better input parameters of sintered raw materials during the sintering process.

Design for Carbon Core Pellet toward Co-production with Sinter

Current global demand for the carbon emission reduction and the depletion progress of high-grade iron ore deposits require the integrated solution toward sinter and ironmaking process. Several countermeasures have been proposed regarding the development of highly reducible burden materials for the blast furnace and the use of beneficiated fine iron ores in the sintering machine. However, their application to actual sintering and ironmaking equipment have been limited because the sinter productivity is deteriorated. Here the present study investigated co-production of the carbon composite pellet and sinter with existing sintering machines. Even if fired in an oxidizing atmosphere, carbon-core-pellets can be produced under conditions that simulate the conventional sintering process. This is because a protective shell over the carbon core inhibits the carbon from combustion. Importantly, the structure and composition of the pellets are properly designed so that this protective shell does not melt overly or break during firing. The design parameters govern the strength and reducibility of pellets after firing, and those influence is analyzed quantitatively. Overall, a pot test trial in which designed pellets have been blended exhibited the viability of the pellet-sinter co-production.

Intelligent optimization system of burden structure in sintering and blast furnace ironmaking process based on improved genetic algorithm

ABSTRACT Under the premise of ensuring the smooth production of the blast furnace, the quality and output of molten iron, minimizing the cost of hot metal and reducing the impact of harmful elements are the most difficult problems faced by iron and steel enterprises at present. The intelligent optimization system of burden structure in the whole process of sintering and blast furnace ironmaking is developed based on the principle of blast furnace ironmaking and material balance, improved genetic algorithm and penalty function. It includes four parts: raw fuel database, intelligent sintering optimization, blast furnace burden structure intelligent optimization and company cost accounting. The industrial application shows that the system can not only guarantee the output and quality of molten iron, but also effectively reduce the cost of molten iron in the process of optimizing the sintering and blast furnace production of the steel company.

Additive manufacturing on the façade: functional use of direct metal laser sintering hatch distance process parameters in building envelope

PurposeThe purpose of this article is on the functional usability of metal additive manufacturing (AM) direct metal laser sintering (DMLS) production technology process parameters in the construction industry. In the study, the advantages of thermal optimization and weight reduction in the case of the use of foam metals obtained by changing the hatch distance the production process parameter, in the production of facade panels in the architectural field are revealed.Design/methodology/approachThe methods in the study; production of the small scaled facade panels with nine different hatch distance parameters, determination of the thermal change with the infrared thermography method, microstructure examination, weight measurement.FindingsThe paper lays the groundwork for the manufacturability of lighter and lower thermal conductivity facade panels by changing the hatch distance parameters. Within the scope of the study, the definition of semi-open-cell foam aluminum and the product screening strategy offers innovation. Within the scope of the study, this scope is shared as an algorithmic summary. In addition, the study offers a new perspective within the scope of multiple optimizable panel production in facade panels with AM technology.Originality/valueHatch distance parameter change was first discussed in this study in the architectural field, and a semi-open cell foam aluminum panel was obtained with the scanning strategy determined within the scope of the study. This panel geometry, which is defined as semi-open cell foam aluminum, can be used as a design element by painting or coating the outer surface, it can be stated that it will also provide thermal and weight optimization.