Estimation of metallic iron in rusted sponge-iron: Dissolution of iron oxides by bromine/methanol

Talanta ◽  
1978 ◽  
Vol 25 (8) ◽  
pp. 486-488 ◽  
Author(s):  
R Cosstick
Keyword(s):  
Iron Oxides ◽  
Metallic Iron ◽  
Sponge Iron ◽  
Iron Dissolution

Microstructure, Stiffness and Corrosion of Bare and Phosphated Specimens Made by Sintering of Structured Iron-Iron Oxide Spheres

2020 ◽  
Vol 405 ◽  
pp. 411-416
Author(s):  
Miriam Kupková ◽  
Martin Kupka ◽  
Renáta Oriňáková ◽  
Radka Gorejová
Keyword(s):  
Iron Oxide ◽  
Iron Oxides ◽  
Metallic Iron ◽  
Galvanic Corrosion ◽  
Iron Phosphate ◽  
Reduction Reaction ◽  
Diffusion Control ◽  
Iron Oxide Particles ◽  
Flow Through ◽  
Iron Iron

Granulated iron oxide particles were incompletely reduced to structured particles comprised metallic iron and residual iron oxides. Structured particles were pressed into prismatic compacts and sintered. Some of sintered specimens were subsequently phosphatized and calcined. Specimens with an iron phosphate coating were found stiffer than specimens without coating. In Hanks' solution, a galvanic corrosion was induced by more noble iron oxides coupled to a less noble metallic iron. This could explain higher corrosion potentials and higher rates of iron dissolution in comparison with a pure iron. The coating of specimens with iron phosphates shifted corrosion potentials towards more negative values and slowed down the dissolution of iron. This was most likely caused by a reduction in oxygen flow through the coating to iron-oxide cathodes, which has enhanced the influence of diffusion control on the kinetics of reduction reaction.

scholarly journals Effect of the reaction of ammonia gas on the swelling of metallic iron and its oxides during nitriding processes

Athenea ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. 38-45
Author(s):  
Oscar Dam G. ◽  
Luis Azocar
Keyword(s):  
Iron Oxides ◽  
Metallic Iron ◽  
Swelling Behavior ◽  
Test Scheme ◽  
Volume Changes ◽  
Ammonia Gas ◽  
Ore Pellets ◽  
Materials Engineering ◽  
Magnetite Pellets ◽  
Institute Of Technology

In order to study the relationship and effect of nitrogen gas in the reducing gases used in the reducibility tests of iron oxides, under isothermal conditions, a test scheme was executed using ammonia gas, such that its decomposition of the gas in the reactor produced a mixture of H2 and N2 gases. Furthermore, the addition of 6% NH3 in a 28% H2 and 68% N2 gas stream was planned to obtain a gas composition of 70% N2 and 30% H2. This would allow comparing the reducibility curves between both conditions, assuming that the possible difference between both conditions to compare the volume changes of the reduced samples. The difference to be studied will be based on the estimation and comparison of the rate of formation of metallic iron in the stages of reduction of Hematite / Magnetite / Wustite (FeO), as well as the effects of nitrogen absorbed by the fresh metallic iron produced, or present. in iron catalysts to produce ammonia, from the reducing gas mixture, on the volume change of the samples. Likewise, the catastrophic volume changes caused by nitrogen are compared by comparing sources of this gas in solid carbonaceous reducers. Keywords: Gaseous Reduction, Direct Reduced Iron, isothermal tests. References [1]O. Dam G. “The Influence of Nitrogen on the Swelling Mechanism of Iron Oxides During Reduction”. Univ. of London. PhD Thesis 1983. [2]J. Bogde. “Thermoelectric Power Measurements in Wustite. Univ. of Michigan”. 1976. [3]O. Dam G. y J. Jeffes. “Model for the Assessment of Chemical Composition of reduced iron ores from single measurements. Ironmaking and Steelmaking”. Vol. 14, N`5. 1987. [4]M. Yang. “Nitriding-Fundamentals, modelling and process optimization”. Tesis PhD. Worcester Polytech Institute. 2012. [5]EL Kasabgy. T and W-K. LU. “The Influence of Calcia and Magnesia in Wustite on the Kinetics of Metallization and Iron Whisker Formation”. Metallurgical 1980 American Society for Metals and the Metallurgical Society of AIME Volume 11b, pp. 410-414. 1980. [6]“Srikar Potnuru Studies nn the Physical Properties and Reduction Swelling Behavior of Fired Haematite Iton ore Pellets”. MSc Thesis. Department of Metallurgical and Materials Engineering National Institute Of Technology, Rourkela May 2012. [7]R. Agarwal, S. Hembram. “To Study the Reduction and Swelling Behavior Iron Ore Pellets”. BSc. Department of Metallurgical and Materials Engineering National Institute Of Technology, Rourkela May 2013. [8]C. Seaton., J. Foster. and J. Velasco. “Structural Changes Occurring during Reduction of Hematite and Magnetite Pellets Containing Coal Char”. Transactions ISIJ, Vol. 23, 1983, pp. [10]C. Bozco. “Interaction of Nitrogen with Iron Surfaces”. Journal of Catalysis 49. pp16-41. 1977. [11]L. Darken y R. Gurry. “Physical Chemistry of Metals”. Mc Graw hIll . 1953. [12]H. Weirdt and Z. Zwell, Trans. AIME. 229. 142. 1969. [13]J. Schulten. Trans. Soc. Faraday. 53, 1363, 1957. [14]E. Barret y C. Wood. Bureau of Mines R-I 3229. 1934

scholarly journals The Impact of Selected Pretreatment Procedures on Iron Dissolution from Metallic Iron Specimens Used in Water Treatment

2019 ◽  
Vol 11 (3) ◽  
pp. 671 ◽  
Author(s):  
Rui Hu ◽  
Arnaud Ndé-Tchoupé ◽  
Mesia Lufingo ◽  
Minhui Xiao ◽  
Achille Nassi ◽  
...  
Keyword(s):  
Particle Size ◽  
Water Treatment ◽  
Metallic Iron ◽  
Future Research ◽  
Dilute Solution ◽  
Steel Wool ◽  
Experimental Conditions ◽  
Iron Dissolution ◽  
Iron Iron ◽  
The Impact

Studies were undertaken to determine the reasons why published information regarding the efficiency of metallic iron (Fe0) for water treatment is conflicting and even confusing. The reactivity of eight Fe0 materials was characterized by Fe dissolution in a dilute solution of ethylenediaminetetraacetate (Na2–EDTA; 2 mM). Both batch (4 days) and column (100 days) experiments were used. A total of 30 different systems were characterized for the extent of Fe release in EDTA. The effects of Fe0 type (granular iron, iron nails and steel wool) and pretreatment procedure (socking in acetone, EDTA, H2O, HCl and NaCl for 17 h) were assessed. The results roughly show an increased iron dissolution with increasing reactive sites (decreasing particle size: wool > filings > nails), but there were large differences between materials from the same group. The main output of this work is that available results are hardly comparable as they were achieved under very different experimental conditions. A conceptual framework is presented for future research directed towards a more processed understanding.

The Determination of Metallic Iron in Sponge Iron

1922 ◽  
Vol 14 (11) ◽  
pp. 1057-1059 ◽  
Author(s):  
CLYDE E. WILLIAMS ◽  
ARVID E. ANDERSON
Keyword(s):  
Metallic Iron ◽  
Sponge Iron
Sign in / Sign up

Export Citation Format

Share Document