NOUFERROUS METALLURGICAL EQUIPMENT

Abstract:Inclusions are inevitable during the steel smelting process, mainly consisting of oxides, sulfides, nitrides and composite. These inclusions have significant physical property differences from the steel matrix, leading to discontinuities in the microstructure and physical properties of the steel, thereby affecting the performance and service life of the steel. Rare earth elements, as modifiers, have shown excellent performance in improving the properties of inclusions, mainly through microalloying, inclusion modification, and improvement of the steel solidification structure to optimize performances of steel. The paper focuses on the modification effects of rare earth elements (RE) on inclusions during steel smelting and their impact on steel performance, systematically summarizes the phenomena, patterns, mechanisms of rare earth-modified inclusions, and their effects on steel properties, analyzes the effects of different rare earth elements (such as Ce, La, Y) on inclusions and structures in steel, discusses the effects of rare earth complex addition and modification of inclusions in conjunction with heat treatment processes, and covers thermodynamic calculations and kinetic analyses of inclusion modification mechanisms. Thermodynamic calculations can predict the formation order and existence form of rare earth inclusions, optimize reaction conditions, and determine the optimal addition amount of rare earth elements. Kinetic analysis shows that rare earth inclusions are prone to collision, agglomeration, and growth during the molten steel temperature and cooling process, floating and removing, which helps to reduce the content of inclusions in the molten steel. The modification of inclusions by rare earth elements can significantly improve the performance of steel, increase the production efficiency of steel, and is of great significance for promoting the sustainable development of the steel industry.

Abstract:The unsatisfactory performance of single inorganic and organic solid electrolytes has driven the development of composite solid electrolytes (CSEs) for solid-state lithium batteries (SSLBs). However, the existence of lithium-depleted space charge layers (SCLs) at the interface of cathode and CSEs (I_C—C) restricts lithium ion transport, which hinders the improvement of ionic conductivity and affects the electrochemical performance of SSLBs. Herein, we report a new type of solid electrolyte composite with bismuth ferrite (BiFeOs). Its presence weakens the lithium-depleted SCLs at the I_C—C, activates lithium ion transport channels, and enables efficient diffusion of lithium ions across various internal interfaces of solid-state batteries. This design achieves a high ionic conductivity of 1.24 mS cm^-1and a high lithium ion transference number of 0.81, which are approximately twice as high as those without BiFeO₃. Consequently, the all-solid-state lithium battery using LiNi_0.9Co_0.05Mn_0.05O₂ cathode exhibits excellent electrochemical performance, retaining 92.3% of its capacity after 200 cycles at 0.5C. This innovation of activating lithium ion transport channels at the interface by weakening lithium-poor SCLs provides a new approach for achieving high-performance composite solid electrolytes and solid-state lithium batteries.

Abstract:In this paper, the effect of Ti/Cr ratio on the microstructures as well as the hydrogen ab/desorption properties of V₄₀(TiCrFe)₆₀ alloy was systematically investigated. It was found that the alloy s lattice constant decreases with the declining of Ti/Cr ratio, from 3.05? for Ti/Cr=1.0 down to 3.023? for Ti/Cr=0.7. Thus, the hydrogen uptake decreases from 3.81 wt% for Ti/Cr=1.0 down to 3.56 wt% for Ti/Cr=0.7, and the hydrogen release plateau increases from 0.135 MPa for Ti/Cr=1.0 up to 1.73 MPa for Ti/Cr=0.7. The decrease in Ti/Cr ratio slows down the hydrogen uptake kinetics of the alloys, and the time to reach the saturation uptake decreases from 2.1 min for Ti/Cr=1.0 down to 3.9 min for Ti/Cr=0.7, which is 85.71% longer, but all of them can reach the saturation hydrogen absorption within 5 min. Additionally, lowering the Ti/Cr ratio increases the hydrogen absorption enthalpy of the V₄₀(TiCrFe)₆₀ alloy from -40.47 kJ/mol at Ti/Cr=1.0 to -26.64 kJ/mol at Ti/Cr=0.7, while the hydrogen desorption enthalpy decreases from 42.82 kJ/mol at Ti/Cr=1.0 to 32.5 kJ/mol at Ti/Cr=0.7, which reduces the stability of the hydrides. The amount of hydrogen desorbed increases from 2.20 wt% at Ti/Cr=1.0 up to 2.37 wt% at Ti/Cr=0.7, which enhances the hydrogen desorption rate of the alloy while reducing the residual hydrogen content. Finally, the V₄₀(TiCrFe)₆₀ alloy with a smaller Ti/Cr ratio shows less capacity decay during the cycling process and a higher cycling retention rate. The alloy with a Ti/Cr ratio of 0.7 has an effective hydrogen storage capacity of 2.22 wt% and a capacity retention rate of 92.12% after 30 cycles. This is attributed to the fact that the alloys with smaller Ti/Cr ratios have smaller particle sizes after pulverization in the initial cycling stage, and the degree of particle size refinement during subsequent cycles is also smaller.

Abstract:The grinding process occupies a core position in mineral processing. It has a significant impact on the surface properties of minerals and the characteristics of the slurry, which in turn further affect the flotation behavior of the minerals. The grinding process not only helps to achieve full monomer dissociation of the minerals, but also has a significant impact on their surface properties, surface roughness, specific surface area, and particle morphology. At the same time, the grinding process also affects the properties of the slurry, such as the pH value, metal ion concentration, dissolved oxygen content, and electrochemical effects in the slurry. These changes directly affect the interaction between minerals and flotation reagents, as well as the separation efficiency. Research shows that factors such as the type of grinding media, the shape of the media, the media ratio, slurry concentration, and mill filling rate can significantly impact the particle size characteristics of the grinding product and flotation performance. In particular, the grinding method (such as dry grinding, wet grinding, or ball milling) affects the physical and chemical properties of the mineral surface differently, thereby influencing the flotation properties of the minerals. This paper reviews the impact of grinding on slurry properties and mineral surface characteristics.

Abstract:The utilization of waste heat is playing an increasingly significant role in energy conservation, production enhancement, quality improvement of products, and cost reduction. It holds important practical significance for China s efforts in achieving energy-saving and emission reduction as well as sustainable development strategies. This study focuses on the efficient and stable operation of core equipment during waste heat recovery and wastewater treatment processes. Basic research and technological development were conducted through the performance analysis and optimization design of flash tanks. Based on the theoretical foundation of flashing, the flash tank was designed and calculated. When treating high-salinity wastewater, it was determined that scaling issues in the heat exchanger equipment before the flash tank inlet must be considered. The use of enhanced heat transfer tubes or scale inhibitors to suppress scale formation is recommended. Experimental studies were carried out to investigate the flashing characteristics of the flash tank. According to the experimental data analysis, when the feed method of the flash tank is water jet injection, the flashing efficiency can reach 90%. When the initial temperature t₁ is 80℃ and the velocity u is 2m/s, after 60 hours of operation, the heat transfer coefficient decreased by 38%. It is estimated that when the slag water flow rate is 3000t/h, the designed flow rate will be reduced by 6t/h.

Abstract:The oxygen injector in the bottom blowing furnace is an immersion oxygen injector, and its gas state of outlet plays a decisive role in the melting process of the bottom blowing furnace, but the outlet information of the oxygen injector cannot be directly detected. In this paper, the numerical simulation research method is used, and the numerical simulation is combined with machine learning, the orthogonal experiment is designed, and the matrix analysis method is used to calculate and predict the outlet information of the oxygen injector. The effects and weights of the gas flow, the angle of the oxygen injector and the liquid level of the bottom blowing furnace on the outlet velocity, outlet pressure and outlet temperature of the oxygen injector were studied. The results show that the gas flow rate has the greatest comprehensive influence on the outlet state of the oxygen injector, while the inclination angle of the oxygen injector has the least effect, and the gas flow state of the outlet of the oxygen injector is the best under the conditions of high flow rate, high liquid level and low inclination angle of the oxygen injector. At the same time, the KNN algorithm is used to establish a fast prediction model, and the results show that the regression coefficient R2 of the indicators of the predicted working conditions and the actual calculated working conditions can reach 0.998, and the prediction accuracy is high, and the prediction model is accurate and reliable.

Abstract:To address the challenges of low efficiency and inconsistent quality in traditional furnace-lining processes for aluminum electrolysis cells, this study proposes an automated robot system based on integrally formed cathodes. Analysis of the furnace-lining process in 200kA aluminum electrolysis cells identified manual construction as the primary cause of defects such as lining cracks and delamination, attributed to insufficient compaction pressure (＜0.8MPa) and uneven temperature distribution. Key performance metrics-including bulk density, resistivity, and compressive strength-were found to fall below industry standards. To address these constraints, a robotic furnace-lining system was developed, integrating shaftless spiral material distribution, vibration compaction, a four-axis gantry mechanism, and 3D laser monitoring. The system achieves autonomous navigation, automated material placement, self-regulated compaction, real-time process monitoring, and electromagnetic compatibility (EMC). Implementation reduced the furnace-lining cycle per cell from 6-7 days (manual operation) to 3 days, providing an innovative solution for high-efficiency, high-precision furnace construction. This advancement supports cost reduction, operational optimization, and intelligent transformation in industrial practice.

Abstract:The resources of zinc concentrate are becoming increasingly scarce and the composition is becoming more complex as well as the chemical reaction process of sulfation roasting, using traditional metallurgical calculation methods for simulation is labor-intensive and inefficient. This article introduces the sulfurization roasting process, reaction mechanism and acidification roasting technology characteristics of zinc sulfide concentrate, and carries out detailed simulation calculation of this process using METSIM. The principle, steps, module division and process control of METSIM model creation are emphatically described. The results show that the sulfuric acid roasting of 157000t/a zinc sulfide concentrate can produce 73804.80t/a roasted sand, 62768.22t/a smoke dust, and 48734.22Nm³/h of flue gas with SO₂ content of 8.8%. 90.62% of the heat income comes from the oxidation and decomposition of sulfides, with materials such as flue gas, smoke, roasted sand,and water evaporation taking away 76.63% of the heat. This provides a detailed theoretical basis for the design and upgrading of the sulfurization roasting process, and the large-scale and super-large-scale equipment.

Abstract:To address the issues of low energy utilization efficiency and ineffective recovery of low-temperature waste heat in copper smelting acid production systems, this study proposes an optimized waste heat recovery process based on thermal exchange principles. Through the application of key equipment including steam generators and high-temperature absorption towers, the system achieves cascade utilization of waste heat. By replacing production water with desalinated water, the quality of sulfuric acid is significantly improved. After commissioning of the recovery unit at SDIC Jincheng Metallurgy, steam production reached 40t/h with annual economic benefits of approximately 26 million yuan. The system demonstrates effective control of equipment corrosion while reducing circulating water power consumption by 560kWh/h. The research provides technical references for energy conservation and emission reduction in the copper smelting industry.

Abstract:In response to the challenges of low nickel and cobalt grades and the difficulty of effectively separating impurity metals in laterite nickel ores, industrial production commonly employs a high-temperature and high-pressure sulfuric acid hydrometallurgical leaching process. This process enables the reaction of metal oxides in the ore with sulfuric acid to form soluble sulfates, facilitating the conversion of nickel, cobalt, and impurity metal ions. To enhance product purity, precise control of precipitation pH is required to achieve effective separation between impurity ions and valuable metal ions. Based on the solubility equilibrium constants of different metal precipitates, this paper derives a pH control formula suitable for actual operating conditions and establishes a theoretical model applicable to industrial production. The research results provide a theoretical basis for efficient impurity removal and product quality improvement, supporting the efficient development and stable operation of laterite nickel ore resources.

Abstract:This paper investigates the application of hydrogen sulfide synthesis processes in copper smelting wastewater treatment. By comparing various hydrogen sulfide synthesis routes and traditional wastewater treatment methods such as sodium sulfide/sodium hydrosulfide sulfidation, neutralization, and combined processes, this study highlights the issues associated with the latter, including the introduction of sodium ions, the generation of large amounts of waste residue, high treatment costs, and unstable water quality. The research demonstrates that the methanol-sulfur synthesis process offers significant advantages in terms of cost, yield, and product purity. Taking a company's project as an example, this process can achieve a removal rate of over 99% for copper and arsenic ions in copper smelting wastewater, and over 95% for lead and zinc ions, enabling the treated wastewater to meet standards for reuse, reducing pollution and saving the company approximately 2 million yuan in wastewater treatment costs annually. Additionally, this study explores the challenges faced in practical applications, such as reaction temperature and pressure control, as well as requirements for raw material ratios and purity, and proposes corresponding strategies. The results indicate that the methanol-sulfur synthesis process is highly effective in copper smelting wastewater treatment, with future development focusing on catalyst research and the automation and intelligentization of the process.

Abstract:A world-class copper mine in Democratic Republic of the Congo requires the construction of six large ventilation shafts, each with a diameter of 6 m and depths ranging from 200 to 400 m, to meet the ventilation demands of underground mining operations. Traditional shaft excavation methods for large-diameter shafts commonly employ the conventional sinking technique, which presents significant safety risks, low construction efficiency, high engineering costs, and prolonged construction periods. To address these issues, this study systematically investigates shaft construction technologies for mine ventilation both domestically and internationally, drawing upon successful international cases utilizing large-diameter raise borers. Base on the specific rock conditions of the mine, an engineering solution was developed to conduct a barrel-type pile foundation and employing a large raise borer for reverse excavation of the shafts. Field implementation demonstrated that the proposed approach successfully achieved the intended engineering objectives, yielding favorable practical outcomes. This raise boring technique effectively mitigated safety risks, saved capital cost, shortened construction duration, and improved project quality, demonstrating significant economic benefits. The research findings provide valuable technical references and practical insights for similar shaft projects in domestic mining operations.

Abstract:The lead electrolytic refining process is a crucial component of current pyrometallurgical lead smelting. This study focuses on the energy-saving and cost-reducing renovation practices in Electrolytic Lead Workshop E. By upgrading key equipment such as electrolytic cells, rectifiers, and anode vertical mold units, Workshop E has achieved significant technological and economic improvements. Post-renovation, the workshop not only enhanced production efficiency and safety but also reduced failure rates and safety risks, while markedly decreasing energy consumption of natural gas and electricity. Five months of operational data indicate that Workshop E's electrolytic lead output is stable and exceeds the designed capacity, with an average production rate of 107.36%. The consumption of natural gas and electricity has significantly decreased, saving the company approximately 3.89 million yuan annually in production costs, including 1.28 million yuan in natural gas, 0.68 million yuan in electricity, and 1.93 million yuan in labor costs. Additionally, the renovation has increased automation levels and optimized the working environment, further enhancing economic benefits. The transformation of Workshop E not only advances lead smelting technology but also delivers substantial economic returns, offering valuable insights for the sustainable development of the electrolytic lead production industry.

Abstract:In response to the significant deviation between actual operating flue gas parameters and design parameters during the desulfurization production of a copper smelting project, which caused severe condensation and corrosion in the front-end fan and piping of the dynamic wave system, this study systematically analyzed various factors, including the desulfurization process, design data, operating parameters, and fan materials. Starting from the corrosion mechanism, and combining theoretical analysis, data evaluation, and practical investigation, the root causes of the problem were thoroughly explored, and a targeted technical modification plan was developed. The implementation of this plan effectively resolved the equipment condensation and corrosion issues, significantly improved the operational availability and production efficiency of the system, and reduced both the copper processing cost per ton and the SO₂ removal expenses.