Sintering Rate Research Articles

Laser powder bed fusion printed poly-ether-ether-ketone/bioactive glass composite scaffolds with dual-scale pores for enhanced osseointegration and bone ingrowth

Although poly-ether-ether-ketone (PEEK) implants hold significant medical promise, their bioinert nature presents challenges in osseointegration and bone ingrowth within clinical contexts. To mitigate these challenges, the present study introduces Diamond PEEK/bioactive glass (BG) composite scaffolds, characterized by macro/micro dual-porous structures, precisely fabricated via laser powder bed fusion (LPBF) technology. The findings indicate that an increase in BG content within these scaffolds significantly augments their hydrophilicity and hydroxyapatite formation capacities. Stress-strain curve analysis demonstrates reliable load-bearing stability across all scaffold types. In vitro assessments confirmed the non-cytotoxicity of PEEK/BG samples and demonstrated improved osteogenic differentiation and mineralization with increased BG incorporation. Further, in vivo experiments illustrated that the Diamond porous structure of these scaffolds facilitated bone growth, an effect notably amplified with higher BG content. Particularly in groups with 15 wt% and 25 wt% BG scaffolds, new bone formation was observed not only within the macropores of the Diamond structure but also within the micropores inside the scaffold rod, suggesting an almost seamless fusion with the new bone. This demonstrates the scaffolds’ effective osteointegration and bone ingrowth properties. This study conclusively established the effectiveness of Diamond-structured PEEK/BG composite scaffolds, fabricated via LPBF, in bone repair. It highlights the crucial role of BG in enhancing osteogenic potential through interaction with the macro/micro pores of the scaffold. Statement of significanceThis study addresses the bioinert nature of PEEK implants by developing Diamond-structured PEEK/bioactive glass (BG) composite scaffolds by laser powder bed fusion. The dual-porous macro/microstructure enhances hydrophilicity and hydroxyapatite formation, vital for bone regeneration. By adjusting the BG content, we controlled the melt viscosity and sintering rate, leading to the formation of beneficial microscale pores. These pores resolve the issue of ineffective bioactive fillers in previous LPBF-fabricated scaffolds, enhancing the osteogenic potential of BG and inducing superior bone ingrowth and osseointegration. In vitro and in vivo analyses show enhanced osteogenic differentiation, mineralization, and bone growth, underscoring the clinical potential of these scaffolds for bone repair.

Studies of the sintering method of ash and slag waste for the production of alumina from self-disintegrating sinters

The goal of this research is to select the optimal composition of the sintering charge of ash and slag waste for maximum extraction of alumina and obtaining self-disintegrating sinters of a given chemical composition. Experiments have shown that sintering of ash and slag waste using two-component charges makes it possible to extract alumina from sinters by no more than 60 %. The highest sintering rates were made using three-component charges. So, when sintering ash and slag waste from Almaty TPP-2 on a three-component charge of the composition CaO:SiO2 = 2; Na2O:(Al2O3+Fe2O3) = 1 at a duration of 60 min and a temperature of 1200 °C, alumina extraction was 83.68 %, under the same conditions, alumina extraction of 87.07 % was obtained during sintering of ash and slag waste from the Eurasian Energy Corporation, and alumina extraction was 90.2 % during sintering of ash and slag waste obtained after preliminary chemical activation.As a result of the conducted research on sintering of ash and slag waste in a three–component charge system, a self-disintegrating sinter of the following chemical composition was obtained, %: Na2O – 0.07; CaO – 26.88; SiO2 – 2.06; Fe2O3 – 5.01; Al2O3– 5.059.

Acceleration of grain boundary diffusion during ultra-fast firing (UHS) of alumina powder compacts

The sintering rate of a ceramic at a given temperature and relative density is often higher if the heating to that sintering temperature is more rapid. This has previous been explained in terms of microstructural coarsening during slow heating, which degrades the sinterability of the body before it reaches the sintering temperature. In this work the sintering of pure alumina with conventional heating rates (CS, 100-900 °C/hour) was compared with ultra-fast firing, using the method known as ultrafast high-temperature sintering (UHS, 120-140 °C/s). Despite the wide difference in heating rate, the SEM microstructures for a given density were similar and a modified Master Sintering Curve analysis of the results showed that the small pore size reduction observed was not sufficient to account for the acceleration in sintering of UHS samples compared with CS. There remained an additional acceleration by a factor of up to ∼20 that was attributed to a higher grain boundary diffusion coefficient in UHS. It is suggested that this is the result of the boundaries forming between powder particles not having time to relax to their lowest energy, most compact structures during UHS, i.e. non-equilibrium grain boundaries. In support of this hypothesis, it is shown that powder compacts that were first partially pre-sintered with conventional heating rates and then subjected to UHS did not show the same acceleration of sintering displayed by UHS of green bodies. The implication is that the slow pre-sintering allowed relaxation of the grain boundaries to low energy structures with low diffusion coefficients.

DETERMINATION OF OPTIMAL PARAMETERS OF SINTERING OF ROLLING SCALE

This article presents the results of studies conducted to determine the optimal parameters of sintering of rolled scale in a mixture with iron-containing steelmaking waste. The conducted studies of sintering of rolled scale have shown that the gas permeability of the charge depends on a number of physical properties, the size and shape of the grains, the amount of return, the height of the charge layer, and the moisture content of the charge. The initial gas permeability strongly depends on the degree of humidification of the agglomeration charge, especially when sintering small classes of materials under study. The maximum gas permeability of the charge is ensured with an optimal granulometric composition of the charge, which is characterized by an average equivalent diameter: the higher this indicator, the higher the gas permeability of the charge. The value of the surface tension reaches its maximum at a certain moisture content of the charge, which is the optimal moisture for this charge. By increasing the amount of return during agglomeration, the vertical sintering rate increases and the quality of the agglomerate improves. These factors lead to an increase in the productivity of sintering plants. According to the results of the study, the optimal parameters of the sintering sintering process of rolled scale in a mixture with iron-containing steelmaking waste were worked out. It is established that the optimal amount of return is the use of 20 % of the mass of the sintering charge at the optimal height of the sintered layer of 300 mm. As a result of the conducted research, the following optimal indicators were achieved: mechanical strength – 70.2 %, sintering rate – 28.7 mm/min, specific productivity – 1.75 t/m2·hour. Keywords: Rolling scale, agglomeration, optimal parameters, sintering, return, layer height.

Competition between surficial and volumetric diffusion in sintering TiO2 polymorphs by molecular dynamics simulation

AbstractThe competition between surficial and volumetric diffusion during the sintering process for ceramic polymorphism at different sintering temperatures is worth deeply exploring. In the current work, various sintering cases of mixed TiO2 nanoparticles with rutile and anatase types were investigated and the effects of crystalline phase, sintering temperature, and particle size on the sintering process were systematically investigated. The difference in thermodynamic stability and surficial activity of the crystalline phase could promote the decomposition and densification of the nanoparticles. Comparing the mixed‐phase sintering process at different sintering temperatures, the results showed that the particle binding process at low temperature relied mainly on surficial diffusion, however, volumetric diffusion played a crucial role at high temperature. The internal occurrence of volumetric diffusion inhibited the surficial diffusion, resulting in a smaller diameter of the sintering neck and a different sintering rate. In the case of sintering three nanoparticles with rutile and anatase types, it could be found that the decomposition of nanoparticles is more uniform in mixed‐phase sintering at high temperatures and the sintering rate is not significantly influenced by the sintering temperature. This work demonstrates the advantage of a mixed‐phase sintering strategy for TiO2 nanoparticles, which could provide insight into ceramic materials with polymorphism.

Ultralow‐Temperature Sintering of Titanium Powder by Spark Plasma Sintering Under Cyclic Pressure

Spark plasma sintering (SPS) is a promising method for producing titanium components from powder but a limitation is that high sintering temperatures (>900 °C) are normally required to eliminate porosity. Herein, the SPS of commercially pure titanium powder is reported using both cyclic and constant uniaxial pressure and compare densification, microstructure, and mechanical behavior. The following parameters are varied: sintering temperature, TS, 400 to 900 °C; cyclic and constant pressures, 100 to 500 MPa; with and without an isothermal dwell of 60 min at TS. The mechanical behavior is determined by bend and tensile testing. It is demonstrated that the application of cyclic pressure (cyclic‐SPS) gives superior densification over the range of parameters investigated compared with a constant pressure. Bend testing reveals improved ductility after cyclic‐SPS compared with a constant pressure. The dwell at TS further improves mechanical properties, giving excellent tensile ductility and strength. Consequently, at the ultralow temperature of 500 °C, nearly fully dense, ductile, titanium is achieved. It is shown that cyclic pressure enhances the degree of powder compaction at room temperature, and mechanisms are proposed to rationalize the effect of cyclic‐SPS on enhancing the rates of densification and sintering as the temperature increases during processing.

Flexural Strength of Different Yttrium Oxide Containing Monochrome and Multilayer Partially Stabilized Zirconia upon Various Sintering Rates.

Purpose: Sintering procedures influence the properties of zirconia. This study evaluated the effect of varying sintering rates on flexural strength (σ) of 3, 4, and 5 mol% yttria (Y) containing monochrome (Mo) and multilayer (Mu) zirconia. Materials and Methods: 270 specimens (width×length×thickness = 11.2×20×1.5 mm) were prepared from Mo and Mu of 3Y, 4Y, and 5Y zirconia and randomly sintered at regular (RS: 10 °C/min), fast (FS: 35 °C/min), and speed (SS: 70 °C/min) sintering (n = 15/group). Three-point bending test was determined for σ. ANOVA and Bonferroni test were analyzed for significant differences of σ (a=0.05). The microstructure and crystalline [monoclinic (m), tetragonal (t), and cubic (c)] phases were evaluated by SEM and XRD.Results: σ of zirconia was affected by zirconia type, shade pattern, and sintering rate. Significant higher σ for 3Y>4Y>5Y (p<0.05). Significant greater σ for Mu>Mo (p<0.05). Significant reduction of σ upon SS than RS and FS (p<0.05). However, no significant effect on σ upon varying sintering rates within each type of zirconia (p>0.05). SEM indicated greater grain size in 5Y than in 4Y and 3Y. XRD indicated higher t phase in 3Y, whereas higher c phase in 5Y. Mo indicated a higher c phase than Mu.Conclusions: σ was influenced by Y content (3Y>4Y>5Y), shade pattern (Mu>Mo), and sintering rate (RS@FS>SS). Nonetheless, no influence of varying sintering rates on σ for each type of zirconia, suggesting sintering zirconia with RS and FS for expecting higher σ and at SS for acceptable σ for chair-side cost-effective restoration.

Microwave‐sintered mullite structural ceramics based on low‐grade bauxite applied for fracturing proppants

AbstractThis study aimed to assess the feasibility of manufacturing fracturing proppants by microwave sintering and using low‐grade bauxite as raw material. The effects of microwave hotspot SiC and sintering additive MnO2 content on the performance of the mullite‐based structural materials were studied, respectively. The optimum sintering condition was determined by single‐factor experiments. The sintering process and mechanism were explored based on the analysis of physicochemical properties, phase transitions, and microstructure. The results showed that (1) mullite ceramic composites could be successfully prepared only with SiC added and with poor interparticle bonding microstructure. (2) With the addition of MnO2 and CaO, the granular‐shaped mullite crystals transformed into rod‐like mullite crystals, forming a net structure. (3) As the input power increased, the overfast sintering rate would reduce proppants' mechanical properties, and it was also necessary to select a reasonable sintering time to avoid overburning. (4) When the mass ratio of MnO2:CaO:SiC:bauxite was 2:1.5:12:84.5 and under the sintering condition of 1000 W, 2 h, the performance (breakage ratio of 8.5% under 28 MPa closed pressure, apparent density of 2.58 g/cm3, turbidity of 52 FTU, and acid solubility of 6.77%) could meet the requirements of the Chinese Petroleum and Gas Industry Standard (SY/T 5108–2014). This study provides a powerful way for reducing the fracturing cost, which not only improves the low‐grade bauxite utilization scale within the ceramic industry, but also expands the application of microwave sintering technology in mullite structural materials for the petroleum and gas industry.

Technology verification of Portland cement clinker production driven by concentrated solar energy directly

Fuel substitution is an important measure for heat substitution and carbon emissions reduction in cement production by using low-carbon fuels such as solid waste, natural gas, biomass energy and solar energy. In this study, a technology that uses concentrated solar energy to directly drive solar cement clinker production is proposed and its feasibility is experimental demonstrated. The results showed that cement clinker could be burned using concentrated solar energy. Because the sintering rate is rapid, rapid burning and/or under-burning also occurs during the sintering process, which causes the clinker structure exhibit a sheet structure. The chemical composition analysis showed that the total mass fraction of dicalcium silicate (C2S) and tricalcium silicate (C3S) exceeded 70 %, the mass fraction of f-CaO was higher than the standard value (≤1.5 %). Controlling the sintering temperature and time, and increasing the cooling rate are significant factors in ensuring the quality of the cement clinker.

Pressureless sintering kinetics analysis of Ti3SiC2 and Ti2AlC powdered MAX phases

This paper reports the pressureless sintering behavior and the activation energy of the powdered MAX phases Ti3SiC2 and Ti2AlC. A non-isothermal technique was used to determine the sintering kinetic parameter. The Ti3SiC2 and Ti2AlC MAX phases showed the maximum sintering rate at 1723 K, 0.14 and 0.10 µm/s, respectively. The sintering rate of the sample at different temperatures followed a cubic equation which was determined. The sintering activation energy (Ea) for the Ti3SiC2 and Ti2AlC samples was 362.1 kJ/mol and 640.3 kJ/mol, respectively.

Thermomechanical and thermodynamic analysis of the sintering process of Mn-based oxygen carrier in chemical looping gasification of biomass

The Mn-based oxygen carrier (OC) owns a great oxygen carrying capacity and a high reactivity in the chemical looping gasification of biomass. However, the sintering of the Mn-based OC can cause serious defluidization or even the shut-down of the biomass chemical looping gasifier. In this study, the sintering kinetics and mechanism of Mn-based OC in the gasification of two typical biomass ash were revealed by thermomechanical and thermodynamic analysis. It revealed that the manganese silicate was converted to iwakiite (MnFe2O4) and liquid at high temperatures in the high-Mn OC (OC2), leading to the liquid sintering mechanism and high apparent activation energy of sintering (Es), with a maximum shrinkage rate of 6.14 %/oC. Conversely, the solid sintering mechanism of the low-Mn OC (OC1) was attributed to the FeMn2O4 crystallization, leading to a low shrinkage rate (The maximum shrinkage rate was 0.30 %/oC). The sintering rate of Mn-based OC was closely related to the liquid content, and the biomass ash addition advantaged the liquid formation. Therefore, the Es of OC1 was increased from 44 kJ/mol to 151 kJ/mol at the 15 wt% addition of corn straw ash, and Es of OC2 was increased from 72 kJ/mol to 93–107 kJ/mol at 20 wt% addition of biomass ash. Element distribution analysis supported that Ca in sawdust ash improved the bonding between Mn and Si, improving the Mn-based minerals crystallization and OC expansion. However, the K in corn straw ash facilitated the melting of rhodonite(MnSiO3), and the expansion of Mn-based OC was inhibited. This study provides valuable insights into the sintering mechanism of the Mn-based oxygen carrier and its relationship with liquid evolution behavior in the chemical looping gasification of biomass.

WB2 ceramics prepared by combination of boro/carbothermal reduction process and spark plasma sintering: Effect of C content and sintering rate

Tungsten diboride ceramics with a relative density higher than 90 % without addition of sintering aid can be prepared by boron/carbothermal reduction method combined with spark plasma sintering. Among the raw materials,WO3, B4C, and C, C content is of vital importance to obtain WB2 bulk samples with high density and good mechanical properties. In the present work, we investigated the effects of C content in powder synthesis, as well as SPS sintering rate on phase composition, microstructure, and Vickers hardness of WB2 bulk samples.WB2 bulk sample with a relative density as high as ∼94 % was obtained with the optimal raw material ratio of WO3:B4C:C=2:1.075:4.8, which was then increased to ∼96 % with the decrease of sintering rate from 100 °C/min to 50 ℃/min. This represents the highest relative density of the pure WB2 ceramic publicly reported in the literatures.

Mechanical Properties of Fe-TiC Composites for Friction Stir Welding Tool Application by a Spark Plasma Sintering

TiC, which has high hardness, was added to reinforcing material to improve the mechanical property of Fe. Fe-TiC composites as a function of TiC contents were fabricated by high energy ball milling and spark plasma sintering. The Fe-TiC composites were synthesized with different TiC contents (5, 10, and 20 wt.%) and subsequently consolidated by rapid sintering at 850℃ under 60 MPa. The relative density of Fe-TiC composites is from 99.5% to 94% as the TiC contents increased. Due to the increased in TiC contents, which contributes to the sintering rate with low wettability and low deformation at high temperature, has resulted in a decrease of relative density. The hardness of Fe-TiC was ranged from 128.9±10.4 to 687.2±14.6 kg/mm 2 as the TiC contents increased. Particularly, the highest hardness of TiC weight percent was 20 wt.% TiC which was related with Hall-Patch relationship. Also this enhancement was attributed to the dispersion strengthening effect of the agglomerated powders and solid solution strengthening through high energy ball milling. Microstructure, and phase analysis of Fe-TiC composites were investigated.

Effect of milling and compaction on sintering of porcelain stoneware tiles

The present study aims to provide a deeper understanding of how different particle size distributions and degrees of powder compaction affect the densification process of porcelain stoneware tiles. For this purpose, three different batches underwent a laboratory simulation of the industrial tilemaking process, at growing grinding time or increasing forming pressure, with technological characterization of both unfired and fired products. Sintering behaviour was determined by hot-stage microscopy. Phase composition was determined by XRD-Rietveld allowing the estimation of the chemical composition and physical properties of the liquid phase. The results illustrate the impact of too fine (or too coarse) grain size on powder compaction, firing shrinkage, water absorption, efficiency of densification, sintering rate, stability at high temperature, and risk of anticipated overfiring (and similarly for too high or too low forming pressure). Simultaneous variation of particle size and forming pressure beyond usual standards induced changes in technological behaviour that in most cases compensate each other. Phase composition is moderately influenced by particle size and little by powder compaction. The vitreous phase mainly suffered from a decreasing degree of polymerization as the particle size became finer or the dry bulk density decreased. In case of insufficient grinding, too much residual feldspars caused improper composition and properties of the glassy phase, which resulted in lower efficiency of densification and slower sintering rate. Both the sintering kinetics and degree of densification depend on the timescale, i.e. the ratio of surface tension to viscosity (melt) and median particle size. Nevertheless, a low powder compaction can trigger a microstructural effect on sintering (improving both densification rate and efficiency) that may outweigh the timescale effect.

Thermally Induced Structure and Functionality Evolution of a Pt‐based Lean NOx Trap Catalyst

Applying a NOx trap catalyst to effectively remove NOx contaminants from the oxygen‐rich exhaust is still very challenging, due to the lack of use guidance based on deactivation mechanisms. The temperature‐dependent Pt sintering rate constant was described using Pt dispersion determined by pulse CO chemisorption. It was found that 700‐850 ºC was the determining temperature regions for the significant Pt sintering, according to the sintering kinetics and the evolution of active Ptδ+ sites. The weak basicity plays a critical role in trapping NOx at low‐temperature (≤ 300 ºC), and the NOx trap efficiency decreases because of the loss of catalytic activity and medium basicity caused by forming BaAl2O4 phase. The reduction of NOx towards N2 on the Pt crystallites smaller than 18 nm is structure sensitive and decreases with losing the reducibility of catalysts. The security for long‐time use of a NOx trap catalyst should be exposed to the exhaust gas within 750 ºC, and effectively removing NOx contaminants requires it to be worked in the 350‐500 ºC regions. These findings can guide engineers and applied chemists how to efficiently use a NOx trap catalyst in the automotive exhaust purification system.

Densification of visco-elastic powders during free and pressure-assisted sintering

This study presents an advanced computational model designed for the analysis of the densification process in visco-elastic powders during sintering. The model incorporates thermo-mechanical aspects into the discrete element method (DEM), and a thermo-rheological model to describe the rate of sintering when visco-elastic particles are in contact at variable temperatures. First, a novel contact model is developed and calibrated using experimental data obtained from dilatometric experiments on PA12 pellets. The calibration process involves measuring the linear (axial) shrinkage of the powder compact pellets with dilatometers and employs Bayesian filtering to identify the model parameters. The calibrated model accurately characterizes the linear shrinkage observed in the PA12 pellets. Subsequently, the study delves into the influence of various process parameters on the evolution of bulk density, commonly referred to as relative density. These investigations provide valuable insights into the impacts of maximum process temperature, holding time process duration, and external pressure, for which our model is capable of providing qualitative descriptions. The findings support the notion that longer process durations and the application of higher external pressure are the main drivers of densification, aligning with expectations in metallurgy techniques. This work offers a predictive DEM tool for computing the densification of pellets made of visco-elastic powders.

Integrated experimental and theoretical studies for unravelling CO2 capture of dual function CeO2-CaO bio-based sorbents

Solid CaO-based sorbents for CO2 capture represent a promising alternative technology compared to traditional amine scrubbing methods. However, CaO-based sorbents are rapidly sinter and easily decrease CO2 uptake capacity with regenerated carbonation–calcination cycle. Thus, in this study, doping CaO with CeO2 make it an excellent candidate for improving stability and facilitating CO2 capture efficiency. The dual function of CaO bio-based sorbents with varying ratios of cerium (Ce) were derived from naturally occurring blood clam using the gel-combustion method. Their nanostructures and physicochemical properties were characterized through the specific methods, including in situ XAS, CO2 chemisorption and physisorption, XPS, XRD, and SEM. An in-depth understanding of CO2 adsorption mechanism was further emphasized using a density functional theory (DFT) simulation. The results demonstrate that nanosized CeO2-CaO, with a mole ratio of 1:9, exhibited the highest performance for CO2 capture (6.44 mmol CO2/g sorbent). It is postulated that Ce serves as a physical barrier, effectively partitioning adjacent CaO grains and thereby diminishing the sintering rate. CaO is identified as the primary adsorption site, in contrast to CeO2. Mixing the Ce-Ca dual oxide initiates the electron-rich O at the O’ site. The electron localization at the O’ active site improves the activity of O’, making the performance CeCa(200) for capturing CO2 capture dominant. This discovery suggests that CeO2-CaO holds promise as a sustainable alternative sorbent for future CO2 capture applications.

Introducing a novel catalyst for efficient conversion of CO2 into syngas through reverse-water-gas-shift (RWGS) reactions based on highly mesoporous structures MCM-41: Influence of the Fe incorporation

The RWGS is the first step in CO2 hydrogenation. This process converts CO2 into valuable compounds, such as methanol, to address the global issue of CO2 emissions. In this research, the performance of a Cu-Fe bimetallic catalyst mounted onto MCM-41 support in RWGS was investigated. Our results demonstrate that MCM-41′s high specific surface area is advantageous for dispersing active metals and preventing their sintering. The Cu-Fe supported on MCM-41 samples are characterized by Scanning Electron Microscopy (SEM), ex situ X-ray Diffraction (XRD), Brunner–Emmet–Teller (BET), and Temperature Programmed Reduction (TPR). In order to investigate the catalytic activity, key variables including a temperature range of 400–600 °C, different H2/CO2 ratios, and various gas hourly space velocities (GHSV) at atmospheric pressure were assessed. In this study, excellent CO2 conversion was attained at a high GHSV (96,000 ml g-1h−1), which is advantageous for the design of smaller reactor volumes. In comparison to industrial Copper-Zinc catalysts and iron-free copper-supported MCM-41 catalysts, which suffer from a high sintering rate at temperatures above 300 °C, adding Iron (Fe) to the copper could increase the catalyst's activity and stability in terms of CO2 conversion and CO selectivity due to the formation of a Cu-Fe alloy. The novelty of this study lies in the assessment of the benefits afforded by bimetallic Cu-Fe catalysts in conjunction with high surface area MCM-41. Also, three different ratios of Cu-Fe (10-1, 7-1, 4-1) were considered for our experiments. The Cu-Fe = 10-1 ratio reached the highest CO2 conversion and CO selectivity value in 600 °C with amounts of 49 % and 99.7 %, respectively.

Experience in implementing machine learning to calculate the quality and production of agglomerate

In 2020, EVRAZ United West Siberian Metallurgical Combine JSC (EVRAZ ZSMK JSC) completed work on the creation of a mathematical modeling system for all processing units of the metallurgical plant. During testing of the system, a high error was found in the existing factor model for predicting agglomerate production, which was developed taking into account the specific sintering rate of individual concentrates. The paper proposes the use of linear regression to predict the productivity of sintering machines, which, unlike nonlinear methods, is optimal for integration into high-performance optimization systems. A feature of the work is forecasting, taking into account the proportion of the agglomeration charge. The model was tested at EVRAZ ZSMK JSC and showed sufficient accuracy (R2 &gt; 90). A large economic effect is expected from the model. A separate study of existing agglomerate quality forecasting systems was conducted. Machine learning (ML) methods have recently made a great contribution to the development of forecasting models used to assess the quality of the agglomerate. This is due to the fact that the sintering process is a very complex dynamic with non‒linearity and a large delay. The physico-chemical phenomena involved in this process are complex and numerous. The neural network can constantly adjust the parameters of the model to reflect changes in systemic causes. A linear method was also studied to predict the agglomerate quality. Due to the poor quality of the resulting linear model, the “random forest” machine learning method was applied. Currently, the model is being operated as part of the integrated optimization program SMM Prognoz for the entire plant. For the convenience of the user, when implementing the module, visualization of the model quality using historical data was added, as well as the statistical metrics obtained.

Илем отқабыршығынан темір кені агломератын алуды зерттеу

The results of a research of the agglomerate production from electric steelmaking wastes are presented. Rolling scale mixed with aspiration dust, final slags of out-of-furnace treatment was used as the main material, and screening of Maykubensky’s coal was used as fuel. The results of the study showed that sintering of rolling scale is advisable to sinter with screenings of Maykubensky’s coal. When sintering rolled scale with 8% of fuel, the best results of the agglomeration process were achieved. It should also be noted that it is advisable to use other steelmaking waste as an agglomeration charge, such as aspiration dust, final slags of non-furnace steel processing as fluxing materials. The sintering rate increases to 20.7 mm/min, the productivity increases significantly to 1.50 t/m2 ·hour. And also the yield on the suitable agglomerate is noticeably increased and the strength of the iron ore agglomerate increases