Influence of the sodium content on the reactivity of carbon anodes

Batista, Jefferson dos Santos; Silveira, B.I.

doi:10.1590/s1516-14392008000300025

Cited by 15 publications

(3 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Fe is an active catalyst for airburn and the CO2 reaction [7]. Sodium, which is not very abundant in the cokes but can enter the anodes from the use of butts [8,9], and other metals that occur in coke in lesser amounts can also affect these reactions. To avoid airburn the anode is covered with anode cover material, usually alumina.…”

Section: Introductionmentioning

confidence: 99%

An EXAFS and XANES Study of V, Ni, and Fe Speciation in Cokes for Anodes Used in Aluminum Production

Jahrsengene

Wells

Sommerseth

et al. 2019

Metall Mater Trans B

View full text Add to dashboard Cite

Lower quality petroleum coke is required to be used in anode manufacture containing S and the metal impurities V, Ni and Fe. These affect the anode performance in the aluminium production process. The chemical identity of the metal species in the coke is not known.Industrial petroleum cokes with high S and containing V, Ni and Fe were analysed by XANES and EXAFS. XANES spectra were compared with standards. EXAFS was used to compare the impurity metal structures with known crystal structures. V is present largely as hexagonal V3S4. Ni is present largely as hexagonal NiS. Fe is present as hexagonal FeS. XAS measurement and analysis

show abstract

Section: Introductionmentioning

confidence: 99%

An EXAFS and XANES Study of V, Ni, and Fe Speciation in Cokes for Anodes Used in Aluminum Production

Jahrsengene

Wells

Sommerseth

et al. 2019

Metall Mater Trans B

View full text Add to dashboard Cite

show abstract

“…Pitch coke is generated by pyrolysis of coal tar pitch, the pyrolysis behavior of pitch is a key factor, − and the pitch coke reactivity directly determines the carbon anode performance. Scholars have investigated trace elements − and additives − for enhancing the pitch coke performance.…”

Section: Introductionmentioning

confidence: 99%

Reaction Behavior of a Trace Element during the Pitch Pyrolysis Process

Liu

Zhang

et al. 2020

ACS Omega

View full text Add to dashboard Cite

The pyrolysis behavior of pitch determines the performance of pitch coke and directly affects the carbon anode air/CO 2 reactivity. The effects of pitch mass and pyrolysis rate on the pyrolysis process of pitch are studied using a self-made pyrolysis device. The effects of Na, Ca, and Mg on pyrolysis kinetics and carbon anode reactivity are also investigated. Results show that the pyrolysis of pitch on the surface and inside of the carbon anode can refer to the kinetic data of small mass asphalt (SMP) and large mass asphalt (LMP), respectively. The pyrolysis process of SMP and LMP conforms to the same dynamic model. The apparent activation energy of SMP is 48.62 kJ/mol and that of LMP is 128.46 kJ/mol. The mass and heating rate of pitch have obvious influences on the LMP pyrolysis process. The apparent activation energy of pyrolysis gradually increases with increasing contents of Na, Ca, and Mg. Moreover, the coke yield and the residual rate of the carbon anode in CO 2 or air increase first and then decrease.

show abstract

“…However, the selective oxidation of the pitch coke during electrolysis causes the coking particles to fall off. Hence, the quality of the pitch coke is important in improving the carbon anode performance, and the process determines the quality of the pitch coke. − The factors affecting the properties of the pitch coke are pitch quality, − trace elements, , additives, − sulfur content in coke, − heating process, − and coke particles . To date, the effects of coke particles on pitch pyrolysis have never been reported.…”

Section: Introductionmentioning

confidence: 99%

Effect of Calcined Coke Size on Pitch Pyrolysis Behavior

Zhang

et al. 2020

ACS Omega

View full text Add to dashboard Cite

Pitch coking determines the quality of pitch coke, which ultimately affects the quality of a carbon anode. In this work, green carbon anodes were studied by scanning electron microscopy (SEM), and the pitch pyrolysis process was tested using a custom-built pyrolysis device. The influence of the coke size on pitch pyrolysis was examined and the action law was analyzed. The results show that the outermost layer of the large size coke has a certain pitch thickness, the subouter layer is filled with a “mixture of fine particles and the pitch,” and the internal area is not soaked by the pitch. Meanwhile, the small particles are soaked and wrapped by the pitch. The pyrolysis dynamics analysis shows that with the increase in particle size, the activation energy gradually increases to 70.00 kJ/mol for 1–2 mm, then rapidly decreases to 31.88 kJ/mol for 3–4 mm, and finally slowly increases to 50.56 kJ/mol for 6–9 mm. When the particle size increases, the coke size <0.5 mm area is dominated by a specific surface area, the 0.5–2 mm area is mainly regulated by a combination of a specific surface area and a porous structure, and the >2–3 mm area is dominated by the porous structure.

show abstract

Influence of the sodium content on the reactivity of carbon anodes

Cited by 15 publications

References 0 publications

An EXAFS and XANES Study of V, Ni, and Fe Speciation in Cokes for Anodes Used in Aluminum Production

An EXAFS and XANES Study of V, Ni, and Fe Speciation in Cokes for Anodes Used in Aluminum Production

Reaction Behavior of a Trace Element during the Pitch Pyrolysis Process

Effect of Calcined Coke Size on Pitch Pyrolysis Behavior

Contact Info

Product

Resources

About