scholarly journals Biocement stabilization of an experimental-scale artificial slope and the reformation of iron-rich crusts

2020 ◽  
Vol 117 (31) ◽  
pp. 18347-18354 ◽  
Author(s):  
Alan Levett ◽  
Emma J. Gagen ◽  
Yitian Zhao ◽  
Paulo M. Vasconcelos ◽  
Gordon Southam
Keyword(s):  
Iron Oxide ◽  
Iron Ore ◽  
Iron Reduction ◽  
Control Experiment ◽  
Mine Waste ◽  
Carbon Sources ◽  
Waste Stabilization ◽  
The Reformation ◽  
Mine Remediation ◽  
Reduction And Oxidation

Novel biotechnologies are required to remediate iron ore mines and address the increasing number of tailings (mine waste) dam collapses worldwide. In this study, we aimed to accelerate iron reduction and oxidation to stabilize an artificial slope. An open-air bioreactor was inoculated with a mixed consortium of microorganisms capable of reducing iron. Fluid from the bioreactor was allowed to overflow onto the artificial slope. Carbon sources from the bioreactor fluid promoted the growth of a surface biofilm within the artificial slope, which naturally aggregated the crushed grains. The biofilms provided an organic framework for the nucleation of iron oxide minerals. Iron-rich biocements stabilized the artificial slope and were significantly more resistant to physical deformation compared with the control experiment. These biotechnologies highlight the potential to develop strategies for mine remediation and waste stabilization by accelerating the biogeochemical cycling of iron.

Effects of metal cations on the fulvic acid (FA) adsorption onto natural iron oxide in iron ore pelletizing process

2016 ◽  
Vol 302 ◽  
pp. 90-99 ◽  
Author(s):  
Youlian Zhou ◽  
Yuanbo Zhang ◽  
Guanghui Li ◽  
Tao Jiang
Keyword(s):  
Iron Oxide ◽  
Fulvic Acid ◽  
Iron Ore ◽  
Metal Cations ◽  
Natural Iron

scholarly journals Measurement and Modeling of Thermal Conductivity for Dense Iron Oxide and Porous Iron Ore Aggliomerates in Stepwise Reduction.

1992 ◽  
Vol 32 (7) ◽  
pp. 829-837 ◽  
Author(s):  
Tomohiro Akiyama ◽  
Hiromichi Ohta ◽  
Reijiro Takahashi ◽  
Yoshio Waseda ◽  
Jun-ichiro Yagi
Keyword(s):  
Thermal Conductivity ◽  
Iron Oxide ◽  
Iron Ore ◽  
Porous Iron ◽  
Stepwise Reduction

scholarly journals Thermodynamic of Liquid Iron Ore Reduction by Hydrogen Thermal Plasma

Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1051 ◽  
Author(s):  
Masab Naseri Seftejani ◽  
Johannes Schenk
Keyword(s):  
Iron Oxide ◽  
Liquid Iron ◽  
Thermal Plasma ◽  
Iron Ore ◽  
Hydrogen Plasma ◽  
Reduction Rate ◽  
Plasma Arc ◽  
Ionization Degree ◽  
Reduction Reactions ◽  
Plasma State

The production of iron using hydrogen as a reducing agent is an alternative to conventional iron- and steel-making processes, with an associated decrease in CO2 emissions. Hydrogen plasma smelting reduction (HPSR) of iron ore is the process of using hydrogen in a plasma state to reduce iron oxides. A hydrogen plasma arc is generated between a hollow graphite electrode and liquid iron oxide. In the present study, the thermodynamics of hydrogen thermal plasma and the reduction of iron oxide using hydrogen at plasma temperatures were studied. Thermodynamics calculations show that hydrogen at high temperatures is atomized, ionized, or excited. The Gibbs free energy changes of iron oxide reductions indicate that activated hydrogen particles are stronger reducing agents than molecular hydrogen. Temperature is the main influencing parameter on the atomization and ionization degree of hydrogen particles. Therefore, to increase the hydrogen ionization degree and, consequently, increase of the reduction rate of iron ore particles, the reduction reactions should take place in the plasma arc zone due to the high temperature of the plasma arc in HPSR. Moreover, the solubility of hydrogen in slag and molten metal are studied and the sequence of hematite reduction reactions is presented.

scholarly journals Characterisation of Tailings from Itakpe Iron Ore Mine, Itakpe, Nigeria

2021 ◽  
Vol 4 ◽  
pp. 1-8
Author(s):  
R.A. Adebimpe ◽  
A.O. Fatoye
Keyword(s):  
Specific Gravity ◽  
Food Chain ◽  
Iron Ore ◽  
Mine Waste ◽  
Cadmium Concentration ◽  
Metal Mobility ◽  
Residual Fraction ◽  
Base Line ◽  
Iron Ore Mine ◽  
Waste Dumps

Knowledge of tailings characteristics is required for utilisation and management purposes in the mining and construction industry. Tailings from the mine waste dumps at Itakpe iron ore mine were collected and analysed in the laboratory to determine their chemical and physical characteristics and these include; permeability, porosity, specific gravity, particle size distribution, chemical composition and bioavailability factor of element. Geochemical speciation with quantitative X-ray powder diffraction was used to evaluate the chemical and mineral composition of Itakpe iron ore tailings. The aim is to offer base line data necessary to assess metal mobility and bioavailability. The distribution of heavy metals such as Cu, Ni, Cd, Cr, Zn and Fe was determined using multi- step sequential extraction. The results obtained indicate that the permeability is 6.24 x 10-3 cm/sec; porosity is 35%; and specific gravity is 3.58. The tailings is well graded and is sand gravel. Nickel and Zinc was found to be considerably high in exchangeable and bound to carbonates fraction which are mobile region and is bound to Fe – Mn oxides which is slightly mobile region but the higher concentration of Ni found in residual fraction. The implication of this result is that Nickel and Zinc partially enter into the food chain. Chromium and Cadmium concentration result indicated that these metals can easily enter into the food chain because of their presence in the mobile region and their higher mobility percentage.

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