The complete oxidation of nuclear graphite waste via thermal treatment: An alternative to geological disposal

Theodosiou, Alex; Jones, Abbie; Burton, Derrick; Powell, Marc Kendall; Rogers, Michael L.; Livesey, V.B.

doi:10.1016/j.jnucmat.2018.05.002

Cited by 25 publications

(5 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Fine mosaic coke has been identified as potential material for the production of special graphite and anode material of battery with its favorable high temperature performance, good electrical conductivity, high strength properties, and high density . The properties of fine mosaic coke play a key role in deciding the quality of its derived artificial carbon materials.…”

Section: Introductionmentioning

confidence: 99%

Thermal Conversion Behavior of Medium–Low–Temperature Coal Tar Pitch During Liquid–Phase Carbonization Process

Zhu

Zhao

et al. 2019

ChemistrySelect

View full text Add to dashboard Cite

Medium–low temperature coal tar pitch (MLP) is a type of aromatic carbonaceous material obtained by the low temperature distillation of low rank coal, and is considered as a desirable raw material for the production of artificial carbon/graphite material. The thermal conversion behaviors of MLP during the liquid‐phase carbonization process were analyzed in detail in this study. Further, the changes of molecular structure and carbon microcrystalline structure of MLP and liquid‐phase carbonization products derived from it were quantitatively investigated by optical microscopy, fourier transform infrared spectroscopy, Raman spectroscopy, X‐ray diffraction, and curve‐fitting method. Results showed that both branched chain and the contents of C=O functional groups in the MLP played a key role in the reaction reactivity. Moreover, temperature of 450 °C was found to be a rapid changing temperature point on the enhancement of thermal conversion of MLP. The stacking height (Lc), parallel layers (N), average number of aromatic rings in each layer (n), ratio of ‘impurity’ structure (RI), ratio of amorphous carbon structure (RAC), ratio of graphite carbon structure (RGC), and ratio of defects graphite carbon structure (RDGC) exhibited a significant change with the improvement of liquid‐phase carbonization temperature.

show abstract

Section: Introductionmentioning

confidence: 99%

Thermal Conversion Behavior of Medium–Low–Temperature Coal Tar Pitch During Liquid–Phase Carbonization Process

Zhu

Zhao

et al. 2019

ChemistrySelect

View full text Add to dashboard Cite

show abstract

“…The graphite sample was heated at 1000 °C in muffle furnace in normal air environment for 15 min. Temperature and time of oxidation were selected from the literature [36]. GR-C Prepared by thermochemical oxidation method.…”

Section: Different Modification Methodsmentioning

confidence: 99%

“…After that, it was washed with distilled water to remove the excess acid and dried in a vacuum oven at 80 °C overnight. Temperature and time of oxidation were selected from the literature [36]. GR-D The graphite sample was placed inside an ozone chamber (model number HTE 703 from SATRA Technology, UK) with an ozone flow rate 0.15 L/min, at 80 °C, and kept for 15 min.…”

Section: Different Modification Methodsmentioning

confidence: 99%

Efficiency of different methods of oxidation of graphite: a key route of graphene preparation

Nair¹,

Saha²,

Dey³

et al. 2021

Graphene and 2D Materials Technol

View full text Add to dashboard Cite

Oxidation of graphite is the first important step for the industrial-scale preparation of graphene by a top-down method using graphite as a starting material. In this study, graphite was oxidized by thermal, chemical (sulphuric acid, ozone, peracetic acid, benzoyl peroxide), thermo-chemical (heat treatment in the presence of sulphuric acid) and mechano-chemical (sonication with sulphuric acid in ozone environment) methods and the efficiency of different oxidation methods was studied through different characterization techniques and crystal simulation. From the results, it was evident that the maximum percentage of functional groups (1.8%) was introduced without much breaking the hexagonal graphitic structure when a mixture of graphite and benzoyl peroxide (1:20 w/w) was heated at 110 °C for 15 min. However, the maximum percentage of defects was generated through the introduction of functional groups as well as breaking of the hexagonal graphitic structure when graphite was sonicated with sulphuric acid (1:10 w/w) in ozone environment at 80 °C for 15 min. The crystal simulation result revealed that virgin graphite has monoclinic symmetry, but after oxidation with BPO it has converted to triclinic crystal symmetry with a significant increase in unit-cell volume from 738.6 Ǻ 3 to 1655.8 Ǻ 3 .

show abstract

“…Surface gasification technique is receiving attention as a potential process for separating 14 C from the pretreated graphite waste once metallic radionuclides have been removed [5,[14][15][16][17][18][19][20][21][22]. As mentioned earlier, with the exception of a small amount of natural generated from neutron activation of nonradioactive nitrogen by covering gas adsorbed on the surface of the graphite.…”

Section: Introductionmentioning

confidence: 99%

Single-Phase Flow Model of a Screw Reactor for Decontamination of Radioactive Graphite Waste Using Surface Gasification

Yang

2022

Processes

View full text Add to dashboard Cite

A screw reactor is a promising apparatus for decontaminating radioactive graphite waste by uniform gasification under ambient air. However, developing the design equation for a screw reactor is difficult due to the reactor’s fundamentally intricate gas and solid interactions. In this study, we performed three-dimensional computational fluid dynamics simulations to predict and characterize the graphite particles that flow through the screw reactor and are thermally gasified. This was done using the Eulerian single-fluid approach coupled with the experimentally established kinetic model for graphite gasification. The numerical results show that the counter-rotating flow, generated along the rotating screw of the reactor by the relative motion of the reactor wall to the rotating screw, mixes particles spatially and reduces their axial velocity. The diameter of the feed graphite particles can be reduced by as much as 28% depending on the screw rotating velocity and the temperature of the reactor shell, according to the conducted numerical calculations. These numerical simulations can be used to provide proper operating parameters for the laboratory-scale screw reactor by which to decontaminate radioactive graphite waste by gasifying the radiocarbons, together with a part of the graphite matrix, on the surface of the graphite particles.

show abstract

The complete oxidation of nuclear graphite waste via thermal treatment: An alternative to geological disposal

Cited by 25 publications

References 20 publications

Thermal Conversion Behavior of Medium–Low–Temperature Coal Tar Pitch During Liquid–Phase Carbonization Process

Thermal Conversion Behavior of Medium–Low–Temperature Coal Tar Pitch During Liquid–Phase Carbonization Process

Efficiency of different methods of oxidation of graphite: a key route of graphene preparation

Single-Phase Flow Model of a Screw Reactor for Decontamination of Radioactive Graphite Waste Using Surface Gasification

Contact Info

Product

Resources

About