Mæling straumnýtni við álframleiðslu með eðalskauti - verkefni lokið
Fréttatilkynning verkefnisstjóra
The project aimed to develop a laboratory cell to advance alternative environmentally friendly inert anode technology for primary aluminium production. This aimed to address the knowledge gap required to achieve inert anode process with a current efficiency comparable to the conventional Hall Héroult process.
The following has been achieved:
1. Primary aluminium production using oxygen evolving inert anode technology is successfully operated with modified low-temperature potassium-based electrolyte at 800 ⁰C under stable 40 A laboratory cell conditions.
2. Various compositions of Cu-Ni-Fe alloys are tested, aiming to form a protective oxide layer against a highly aggressive electrolyte bath. To achieve this, a high-temperature air oxidation treatment of the alloy is developed to create a protective and conductive NiFe2O4 oxide layer, which proves effective in stabilizing the alloy during aluminium electrolysis.
3. The evaluation of the inert anode alloy during electrolysis is based on wear rate, aluminium purity, current efficiency, and post-electrolysis oxide layer condition. It is demonstrated that specific combinations of low-temperature electrolyte with high alumina solubility and Cu-Ni-Fe alloy composition can meet the requirements of inert anode technology.
4. Some energy savings are shown for inert anode technology compared to the Hall Héroult process with experiments measuring the anodic overpotential.
5. The electrolysis cell shows remarkable stability even with abrupt changes in bath temperature and current density within defined limits. This suggests the potential use of a full-size cell (100 kA or more) for grid load balancing.
Information on how the results will be applied:
The results of this report demonstrate that primary aluminium production using inert anode technology in a low-temperature electrolyte at 800 ⁰C was achieved. Additionally, electrolysis experiments examine various process parameters to assess the performance of electrolyte composition and inert anode alloys. Energy savings in inert anode technology, determined through anodic overpotential comparisons with the Hall Héroult process, have been assessed. Moreover, the inert anode cell exhibited remarkable stability despite abrupt changes in bath temperature and current, indicating its potential for large-scale grid load balancing.
While these findings are promising, further investigation is needed for long-term validation.
A list of the project’s outputs:
1. Establishment of an environmentally friendly alternative inert anode technology for aluminium production is demonstrated in laboratory cell.
2. Evaluation of low-temperature electrolytes and process parameters of inert anode technology is done.
3. Assessment of Cu-Ni-Fe alloys as inert anodes is reported.
4. Determination of energy savings through measurements of anodic overpotential is reported.
Heiti verkefnis: Mæling
straumnýtni við álframleiðslu með eðalskauti - Measuring
Current Efficiency in an Inert anode Cell for Aluminium production
Verkefnisstjórar: Kamaljeet Singh, Háskólanum
í Reykjavík
Tegund styrks: Doktorsnemastyrkur
Styrktímabil: 2020-2022
Fjárhæð styrks kr. 19.845.000
Tilvísunarnúmer Rannsóknasjóðs: 207242
