THERMAL DECOMPOSITION OF FeOCl AND MARINE CAST IRON CORROSION PRODUCTS

1977 ◽  
Vol 22 (3) ◽  
pp. 146-157 ◽  
Author(s):  
N.A. NORTH ◽  
C. PEARSON
Keyword(s):  
Thermal Decomposition ◽  
Cast Iron ◽  
Corrosion Products ◽  
Iron Corrosion

Chemical Interactions in the Near-Field of a Spent Fuel Repository - Preliminary Results from a Long-Term Laboratory Experiment

2002 ◽  
Vol 713 ◽  
Author(s):  
H. Aalto ◽  
T. Carlsson ◽  
H. Kumpulainen ◽  
J. Lehikoinen ◽  
A. Muurinen
Keyword(s):  
Cast Iron ◽  
Laboratory Experiment ◽  
Near Field ◽  
External Solution ◽  
Corrosion Products ◽  
Spent Fuel ◽  
Iron Corrosion ◽  
N2 Atmosphere ◽  
External Water ◽  
Set Up

ABSTRACTA ten-year-long laboratory experiment was recently started in order to study interactions between the groundwater, the bentonite, and the canister in the near-field of the planned Finnish repository for spent nuclear waste. The experimental set-up consists of a number of samples containing sodium MX-80 bentonite and cast iron cylinders placed in copper vessels. The bentonite stays in contact with an external solution, either distilled water or a 0.5 M NaCl solution, via metal sinters. The experiments are performed under anoxic conditions (N2 atmosphere) at ambient room temperature (∼30 °C). The experimental measurements focus mainly on the development of (1) the water chemistry, (2) the cast iron corrosion, and (3) the diffusion of corrosion products inside the bentonite, since these processes are the most likely ones to produce detectable changes during the ten-year-long programme.The first analyses, after 9 months, showed that the iron corrosion had started and that the corrosion products had migrated into the bentonite. The corrosion products could not be identified by XRD, which either meant that the material was amorphous or present in concentrations too low to be detectable. The analyses of the gas phase indicated the presence of hydrogen, which most probably was the result of the iron corrosion. The compositions of the external water and the porewater were determined with regard to the major species of interest. A closer evaluation of the results will not be given until more data are at hand.

scholarly journals The bacterial community significantly promotes cast iron corrosion in reclaimed wastewater distribution systems

Microbiome ◽  
2018 ◽  
Vol 6 (1) ◽  
Author(s):  
Guijuan Zhang ◽  
Bing Li ◽  
Jie Liu ◽  
Mingqiang Luan ◽  
Long Yue ◽  
...  
Keyword(s):  
Cast Iron ◽  
Bacterial Community ◽  
Distribution Systems ◽  
Reclaimed Wastewater ◽  
Iron Corrosion

scholarly journals Remedial Treatment of Corroded Iron Objects by EnvironmentalAeromonasIsolates

2018 ◽  
Vol 85 (3) ◽  
Author(s):  
Wafa M. Kooli ◽  
Thomas Junier ◽  
Migun Shakya ◽  
Mathilde Monachon ◽  
Karen W. Davenport ◽  
...  
Keyword(s):  
Iron Reduction ◽  
Building Materials ◽  
Solid Phase ◽  
Corrosion Products ◽  
Metal Corrosion ◽  
Economic Losses ◽  
Cytotoxic Activities ◽  
Iron Corrosion ◽  
Pathogenic Potential ◽  
Wide Range

ABSTRACTUsing bacteria to transform reactive corrosion products into stable compounds represents an alternative to traditional methods employed in iron conservation. Two environmentalAeromonasstrains (CA23 and CU5) were used to transform ferric iron corrosion products (goethite and lepidocrocite) into stable ferrous iron-bearing minerals (vivianite and siderite). A genomic and transcriptomic approach was used to analyze the metabolic traits of these strains and to evaluate their pathogenic potential. Although genes involved in solid-phase iron reduction were identified, key genes present in other environmental iron-reducing species are missing from the genome of CU5. Several pathogenicity factors were identified in the genomes of both strains, but none of these was expressed under iron reduction conditions. Additionalin vivotests showed hemolytic and cytotoxic activities for strain CA23 but not for strain CU5. Both strains were easily inactivated using ethanol and heat. Nonetheless, given a lesser potential for a pathogenic lifestyle, CU5 is the most promising candidate for the development of a bio-based iron conservation method stabilizing iron corrosion. Based on all the results, a prototype treatment was established using archaeological items. On those, the conversion of reactive corrosion products and the formation of a homogenous layer of biogenic iron minerals were achieved. This study shows how naturally occurring microorganisms and their metabolic capabilities can be used to develop bio-inspired solutions to the problem of metal corrosion.IMPORTANCEMicrobiology can greatly help in the quest for a sustainable solution to the problem of iron corrosion, which causes important economic losses in a wide range of fields, including the protection of cultural heritage and building materials. Using bacteria to transform reactive and unstable corrosion products into more-stable compounds represents a promising approach. The overall aim of this study was to develop a method for the conservation and restoration of corroded iron items, starting from the isolation of iron-reducing bacteria from natural environments. This resulted in the identification of a suitable candidate (Aeromonassp. strain CU5) that mediates the formation of desirable minerals at the surfaces of the objects. This led to the proof of concept of an application method on real objects.

Analogues for the Corrosion-induced Expansion of Iron in HLW containers

2003 ◽  
Vol 807 ◽  
Author(s):  
Nicholas R. Smart ◽  
Rachel Adams ◽  
Lars Werme
Keyword(s):  
Cast Iron ◽  
Natural Waters ◽  
Spent Nuclear Fuel ◽  
Severe Damage ◽  
Geologic Repository ◽  
Iron Corrosion ◽  
Aqueous Environments ◽  
Archaeological Materials ◽  
Anaerobic Corrosion ◽  
Magnetite Film

ABSTRACTIn Sweden, spent nuclear fuel will be encapsulated in sealed cylindrical canisters, consisting of a cast iron insert and a copper outer container. The canisters will be placed in a deep geologic repository and surrounded by bentonite. If a breach of the outer copper container were to occur the cast iron insert would undergo anaerobic corrosion, forming a magnetite film whose volume would be greater than that of the base metal. In principle there is a possibility that accumulation of iron corrosion product could cause expansion of the copper canister. Anaerobic corrosion rates are very slow, so in the work described in this paper reference was made to analogous archaeological materials that had been corroding for long periods in natural anoxic aqueous environments. This paper describes a number of archaeological artefacts containing iron and copper corroding in constrained geometries in anoxic natural waters. No evidence has been obtained which would suggest that severe damage is likely to occur to waste canisters as a result of expansive corrosion of cast iron under repository conditions.

scholarly journals Thermal decomposition characteristics of foundry sand for cast iron in nitrogen atmosphere

2018 ◽  
Vol 5 (12) ◽  
pp. 181091 ◽  
Author(s):  
Qingwei Xu ◽  
Kaili Xu ◽  
Xiwen Yao ◽  
Jishuo Li ◽  
Li Li
Keyword(s):  
Activation Energy ◽  
Thermal Decomposition ◽  
Cast Iron ◽  
Low Cost ◽  
Temperature Stability ◽  
Nitrogen Atmosphere ◽  
High Temperature Stability ◽  
Kinetics Parameters ◽  
Foundry Sand ◽  
Exponential Factor

Sand casting, currently the most popular approach to the casting production, has wide adaptability and low cost. The thermal decomposition characteristics of foundry sand for cast iron were determined for the first time in this study. Thermogravimetry was monitored by simultaneous thermal analyser to find that there was no obvious oxidation or combustion reaction in the foundry sand; the thermal decomposition degree increased as the heating rate increased. There was an obvious endothermic peak at about 846 K due to the transition of quartz from β to α phase. A novel technique was established to calculate the starting temperature of volatile emission in determining the volatile release parameter of foundry sand for cast iron. Foundry sand does not readily evaporate because its volatile content is only about 2.68 wt% and its main components have high-temperature stability. The thermal decomposition kinetics parameters of foundry sand, namely activation energy and pre-exponential factor, were obtained under kinetics theory. The activation energy of foundry sand for cast iron was small, mainly due to the wide temperature range of thermal decomposition in the foundry sand.

Sorption of Th(IV) onto Iron Corrosion Products: EXAFS Study

2009 ◽  
Vol 43 (8) ◽  
pp. 2825-2830 ◽  
Author(s):  
Ferran Seco ◽  
Christoph Hennig ◽  
Joan de Pablo ◽  
Miquel Rovira ◽  
Isabel Rojo ◽  
...  
Keyword(s):  
Corrosion Products ◽  
Iron Corrosion ◽  
Exafs Study
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