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17 pages, 7742 KiB

Open AccessArticle

Modification of Desulfurization Slag for Hot Metal Bearing V-Ti and Industry Application

by Jun Chen, Lian Chen and Lijun Wang

Metals 2025, 15(3), 245; https://doi.org/10.3390/met15030245 - 25 Feb 2025

Cited by 1 | Viewed by 757

In view of the high loss of iron during hot metal desulfurization treatment at Pangang Steel, the factors influencing slag skimming iron loss were analyzed thoroughly by thermodynamic calculation with the aid of FactSage. A desulfurization modifier containing Na₂O and Al₂O₃ was designed. An industrial verification test was conducted for the newly designed calcium-based agent. The test results indicate that adding 8% of the modifier to the passivating lime achieves the optimal modification effect on the desulfurization slag. After modifying the desulfurization slag, the consumption of magnesium powder for every 0.001% sulfur removed decreased from 0.0149 kg to 0.0136 kg, the iron loss during slag skimming reduced from 3.52% to 2.28%, and the average slag skimming time shortened by 1.5 min. These improvements significantly lowered production costs, enhanced desulfurization efficiency, and laid the foundation for the widespread application of the semi-steel silicon addition process. Full article

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12 pages, 1879 KiB

Open AccessArticle

Efficient Recovery of Vanadium and Titanium from Domestic Titanomagnetite Concentrate Using Molten Salt Roasting and Water Leaching

by Ha Bich Trinh, Seunghyun Kim, Jaeryeong Lee and Seokhoon Oh

Materials 2023, 16(21), 6918; https://doi.org/10.3390/ma16216918 - 27 Oct 2023

Cited by 4 | Viewed by 1433

Abstract

The traditional roasting technique using sodium salts in vanadium production has been disadvantageous due to the large consumption of energy and the emission of harmful gases. A modified process using molten salt roasting and water leaching to extract vanadium and titanium from domestic titanomagnetite concentrate was investigated. The roasting process was performed under optimal conditions: the weight ratio between the sample and NaOH of 1:1, the temperature of 400 °C, and the experiment time 90 min, and the conversion of vanadium could be maximized to 90%. The optimization of water leaching (at 60 °C for 90 min with a pulp density of 0.05 g/mL) could extract 98% of the vanadium from the roasted products into the solution, leaving titanium and iron remaining in the residue. Further purification of vanadium and titanium using the precipitation/hydrolysis process followed by calcination obtained the final products V₂O₅ and TiO₂ with high purities of 90% and 96%, respectively. A potential approach with modification of the roasting stage using NaOH was proposed, which was not only efficient to selectively extract the value metals from the titanomagnetite but also eco-friendly based on the reduction in energy consumption and emission of harmful gases. Full article

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17 pages, 4909 KiB

Open AccessArticle

Prediction of the Vanadium Content of Molten Iron in a Blast Furnace and the Optimization of Vanadium Extraction

by Hongwei Li, Xin Li, Xiaojie Liu, Xiangping Bu, Shujun Chen, Qing Lyu and Kunming Wang

Separations 2023, 10(10), 521; https://doi.org/10.3390/separations10100521 - 25 Sep 2023

Cited by 7 | Viewed by 1900

Abstract

The vanadium content of molten iron is an important economic indicator for a vanadium–titanium magnetite smelting blast furnace, and it is of great importance in blast furnace production to be able to accurately predict it and optimize the operation of vanadium extraction. Based on the historical data of a commercial blast furnace, the clean data were obtained by processing the missing data and outlier data for data mining analysis and model development. A combined wavelet-TCN model was used to predict the vanadium content of molten iron. The average Hurst index after wavelet transform was calculated to reduce the complexity of the wavelet transform layer selection and the model computation time. The results show that compared to single models, such as LSTM, LSTM with attention, and TCN, the combined model based on wavelet-TCN (a = 5) had an improvement of about 11~17% in R², and the prediction accuracy was high and stable, which met the practical requirements of blast furnace production. The factors affecting the vanadium content of molten iron were analyzed, and the measures to increase the vanadium content were summarized. A blast furnace should avoid increasing the titanium dioxide load, increase the vanadium load appropriately, and keep the relevant operating parameters within the appropriate range in order to achieve the optimization of vanadium extraction from molten iron. Full article

(This article belongs to the Special Issue Research Progress in Separation and Extraction of Ferrous and Non-ferrous Metals)

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16 pages, 6413 KiB

Open AccessFeature PaperArticle

Titanium Impurity Control in V-Bearing Pig Iron Prepared via the Sodium Smelting of Vanadium–Titanium Magnetite

by Zhiwei Bian, Lei Cao, Desheng Chen, Hongxin Zhao, Tao Qi, Lina Wang and Yulan Zhen

Metals 2023, 13(9), 1620; https://doi.org/10.3390/met13091620 - 19 Sep 2023

Cited by 3 | Viewed by 1753

Abstract

The sodium smelting of vanadium–titanium magnetite (VTM) can realize a multi-component comprehensive utilization of VTM. To broaden the application of the vanadium-bearing pig iron produced through this process, it is imperative to maintain the titanium content in molten iron at a very low level. In this study, the effects of temperature, the added amounts of sodium carbonate and anthracite, and the smelting time on the titanium content of molten iron were investigated using thermodynamic calculations and experiments. The results indicate that the introduction of sodium carbonate makes the reduction reaction of VTM a relatively low-temperature smelting system. In the smelting process, the Ti content in molten iron increases with the increase in temperature and decreases with the addition of sodium carbonate, while the amount of anthracite added has little effect on it. The appropriate technological parameters were determined as temperature: 1150–1250 °C, smelting time: ≥2 h, anthracite consumption: 25–35%, and sodium carbonate consumption: ≥60%. In addition, it was determined that the Ti impurities in the V-bearing pig iron were mainly (Ti,V)(C,N), CaTiO₃, and Na₂TiO₃. All results obtained from this work contribute to the comprehensive utilization of VTM, and also provide theoretical support for the sodium smelting of VTM. Full article

(This article belongs to the Special Issue Inclusion Metallurgy (2nd Edition))

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13 pages, 6612 KiB

Open AccessArticle

Fusion Separation of Vanadium-Titanium Magnetite and Enrichment Test of Ti Element in Slag

by Shuangping Yang, Shouman Liu, Shijie Guo, Tiantian Zhang and Jianghan Li

Materials 2022, 15(19), 6795; https://doi.org/10.3390/ma15196795 - 30 Sep 2022

Cited by 4 | Viewed by 2398

Abstract

In view of the problem that the enrichment and migration law of the Ti element in the slag of vanadium-titanium magnetite during the melting process is not clear, the phase transformation is not clear and the enrichment effect is not obvious, the single factor experiment and orthogonal experiment are used to optimize the melting conditions of Ti enrichment. Through XRD, SEM and EDS analysis, the effects of melting temperature, alkalinity and carbon content on the Ti phase in the slag are studied, and the occurrence form and migration law of the Ti element in the slag system under different melting conditions are clarified. The results demonstrate that increasing the basicity and melting temperature is beneficial to the enrichment of Ti, but it is too high it will lead to the formation of pyroxene, diopside and magnesia-alumina spinel, affecting the enrichment of Ti. The increase in carbon content can make Ti occur in slag in the form of titanium oxides such as TiO, TiO₂, Ti₂O₃ and Ti₃O₅, but excessive carbon content leads to the excessive reduction of Ti compounds to TiCN and TiC. After optimization, under the melting conditions of alkalinity 1.2, the melting temperature 1500 °C and carbon content 15%, the content of Ti in slag can reach 18.84%, and the recovery rate is 93.54%. By detecting the content of Fe and V in molten iron, the recovery rates are 99.86% and 95.64%, respectively. Full article

(This article belongs to the Topic Advanced Processes in Metallurgical Technologies)

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15 pages, 17622 KiB

Open AccessArticle

Effects of Basicity and MgO in Slag on the Behaviors of Smelting Vanadium Titanomagnetite in the Direct Reduction-Electric Furnace Process

by Tao Jiang, Shuai Wang, Yufeng Guo, Feng Chen and Fuqiang Zheng

Metals 2016, 6(5), 107; https://doi.org/10.3390/met6050107 - 10 May 2016

Cited by 55 | Viewed by 9957

Abstract

The effects of basicity and MgO content on reduction behavior and separation of iron and slag during smelting vanadium titanomagnetite by electric furnace were investigated. The reduction behaviors affect the separation of iron and slag in the direct reduction-electric furnace process. The recovery rates of Fe, V, and Ti grades in iron were analyzed to determine the effects of basicity and MgO content on the reduction of iron oxides, vanadium oxides, and titanium oxides. The chemical compositions of vanadium-bearing iron and main phases of titanium slag were detected by XRF and XRD, respectively. The results show that the higher level of basicity is beneficial to the reduction ofiron oxides and vanadium oxides, and titanium content dropped in molten iron with the increasing basicity. As the content of MgO increased, the recovery rate of Fe increased slightly but the recovery rate of V increased considerably. The grades of Ti in molten iron were at a low level without signiﬁcant change when MgO content was below 11%, but increased as MgO content increased to 12.75%. The optimum conditions for smelting vanadium titanomagnetite were about 11.38% content of MgO and quaternary basicity was about 1.10. The product, vanadium-bearing iron, can be applied in the converter steelmaking process, and titanium slag containing 50.34% TiO₂ can be used by the acid leaching method. Full article

(This article belongs to the Special Issue Recycling of Metals)

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