Novel and green metallurgical technique of comprehensive utilization of refractory limonite ores

Wu, Fangfang; Cao, Zhanfang; Wang, Shuai; Zhong, Hong

doi:10.1016/j.jclepro.2017.09.198

Cited by 51 publications

(16 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The gangue minerals chiefly consisted of alunite and quartz. When coal powder is employed as a reducing agent for roasting, the main chemical reactions for the coal-based direct reduction of Fe and Cr in this experiment and Gibbs free energy are as expressed in eqs –. − …”

Section: Resultsmentioning

confidence: 96%

Effective Separation and Beneficiation of Iron and Chromium from Laterite Sulfuric Acid Leach Residue

Lei

Chen

et al. 2020

ACS Sustainable Chem. Eng.

View full text Add to dashboard Cite

The utilization of laterite sulfuric acid leach residue has always been a challenge in the metallurgical industry. The current treatment involves deep-sea landfills, which leads to considerable environmental pollution and resource wastage. In this work, an effective method is proposed to recover iron and chromium from sulfuric acid leach residue. The effects of roasting temperature, reducing agent dosage, and reaction duration on the recovery of iron and chromium were investigated. The optimum conditions were as follows: roasting temperature of 1200 °C, reducing agent dosage of 30%, and reaction duration of 60 min. Results show that the concentrate contains 87% Fe and that only 0.7% S can be obtained with an iron recovery of 82%, indicating suitability for ironmaking. Meanwhile, 85% of chromium can be beneficiated in tailings at a chromium content of 3.5%. The microstructure and composition of reduction products were analyzed by XRD, SEM, and EDS to understand the phase transformation and the aggregation of the reduction products. Hematite in the leach residue is first reduced to FeS and Fe3O4 at low temperature and then reduced to metallic iron with increased temperature. Sulfur is combined with alunite to form FeS at a low temperature, and the decomposition of chromite at high temperature leads to the formation of chromium oxide. In a high temperature and reducing atmosphere, Cr2O3 reacts with FeS to transform Fe and CrS. Through the reduction roasting–magnetic separation process, most of the iron is beneficiated in the concentrate, and nonmagnetic minerals such as FeS and CrS remain in the tailings. Consequently, the separation and beneficiation of iron and chromium occur. The process is economically feasible and environmentally friendly and thus has great potential for the industrial-scale recycling of laterite sulfuric acid leach residue.

show abstract

Section: Resultsmentioning

confidence: 96%

Effective Separation and Beneficiation of Iron and Chromium from Laterite Sulfuric Acid Leach Residue

Lei

Chen

et al. 2020

ACS Sustainable Chem. Eng.

View full text Add to dashboard Cite

show abstract

“…Zhao et al 23 also revealed the ideal condition obtained from the method mentioned above, which consisted of preheating at 550°C. Wu et al 24,25 reported the phase transformation of the iron present in the limonite ore sample by microwave treatment with the addition of alkaline lignin. The iron oxides present in the limonitic sample can be reduced to magnetic iron oxides, including γ-Fe 2 O 3 and Fe 3 O 4 in the following sequence: FeOOH / α-Fe 2 O 3 ➔ γ-Fe 2 O 3 ➔Fe 3 O 4 with the addition of alkaline lignin below 5%.…”

Section: Degree Of Reduction Of the Mixtures As Amentioning

confidence: 99%

Evaluation of the Use of Microwave Energy on The Reduction of Iron Ore and Steelmaking Mill Scale Composite Self-Reducing Mixtures

et al. 2022

View full text Add to dashboard Cite

With the growing industrialization, there is a constant increase in the world demand for steel, causing an increase on extraction of low-grade iron ores, which bear high levels of impurities. A feasible alternative is the use of residues from steel rolling processes (steelmaking mill scale) generated in the steel industry, which are composed of iron oxides consisting mainly of wustite (FeO), hematite (Fe 2 O 3 ) and magnetite (Fe 3 O 4 ). In line with the recycling of wastes, the application of heating by microwave energy in ironmaking processes consists in a promising new method developed in recent decades and is considered a cleaner technique. Therefore, this study aims to evaluate the self-reduction of mixtures composed of iron ore and steelmaking mill scale as iron source, together with coke fines as carbon source, heated using microwave energy. Through the rotational central composite design technique, it was possible to evaluate the best conditions for the use of steelmaking scale residue as well as the effect of the applied microwave energy power. The results indicated that the developed process has relevant utility with up to 41.48% of reduction obtained. The outcomes contribute to a better understanding of iron recovery from steelmaking residues in reduction processes using microwave energy for heating, providing significant insight for the development of new clean technologies.

show abstract

“…Diverse mineral components, complex associated relationships between minerals, and low-grade useful components are the main characteristics of refractory low-grade iron ore. Moreover, the common impurity elements silicon, aluminum, and phosphorus in the refractory iron ore mostly exist in the form of alumina, kaolinite, aluminosilicate, chlorite, iron silicate, and iron olivine, and are complexed with iron minerals [12][13][14]. Currently, solvable methods for the efficient beneficiation of refractory low-grade iron ore are further discussed, such as improving mineral liberation and developing highly efficient separation processes, which have been explored to enhance refractory low-grade iron ore separation [15][16][17].…”

Section: Introductionmentioning

confidence: 99%

Clean Utilization of Limonite Ore by Suspension Magnetization Roasting Technology

Jin

Zhu

et al. 2022

Minerals

View full text Add to dashboard Cite

As a typical refractory iron ore, the utilization of limonite ore with conventional mineral processing methods has great limitations. In this study, suspension magnetization roasting technology was developed and utilized to recover limonite ore. The influences of roasting temperature, roasting time, and reducing gas concentration on the magnetization roasting process were investigated. The optimal roasting conditions were determined to be a roasting temperature of 480 ℃, a roasting time of 12.5 min, and a reducing gas concentration of 20%. Under optimal conditions, an iron concentrate grade of 60.12% and iron recovery of 91.96% was obtained. The phase transformation, magnetism variation, and microstructure evolution behavior were systematically analyzed by X-ray diffraction, vibrating sample magnetometer, and scanning electron microscope. The results indicated that hematite and goethite were eventually transformed into magnetite during the magnetization roasting process. Moreover, the magnetism of roasted products significantly improved due to the formation of ferrimagnetic magnetite in magnetization roasting. This study has implications for the utilization of limonite ore using suspension magnetization roasting technology.

show abstract

Novel and green metallurgical technique of comprehensive utilization of refractory limonite ores

Cited by 51 publications

References 23 publications

Effective Separation and Beneficiation of Iron and Chromium from Laterite Sulfuric Acid Leach Residue

Effective Separation and Beneficiation of Iron and Chromium from Laterite Sulfuric Acid Leach Residue

Evaluation of the Use of Microwave Energy on The Reduction of Iron Ore and Steelmaking Mill Scale Composite Self-Reducing Mixtures

Clean Utilization of Limonite Ore by Suspension Magnetization Roasting Technology

Contact Info

Product

Resources

About