Promising results for aluminium production with CO2 capture

IFE and Nordic Mining have for several years worked at finding a profitable and environment friendly way to produce alumina from the mineral anorthosite. In Gudvangen by the Nærøyfiord, in Sogn og Fjordane county, Nordic Mining is the owner of a field estimated to hold 500 million tons of this mineral.

Nowadays, about 85 % of the aluminium in the world is produced from bauxite. This production is associated with some negative environmental consequences and important CO₂-emissions.

- For example, the so called «red mud» is a well-known waste problem related to this aluminium production. The problem can be avoided by using anorthosite as raw material. We are aiming at developing a more environment friendly method, Mastin emphasises.

For many years it is has been an ambition to produce alumina as raw material for aluminium, from the Gudvangen field. So far it has not succeeded finding a method that ensures the profitability. But now IFE has found a concept with very promising results.

Mainly two people from IFE are involved in the project, Project manager Johann Mastin to the right and Post. Doc. Maria Asuncion Aranda Sanchez to the left in the photo. Aranda has executed most of the lab work. – Also a former IFE-employee, Ingo Machenbach, is in title to his share of the credit for developing the concept, adds Mastin.

The new method has been tested through several process experiments in IFE’s laboratories at Kjeller. The process is based on the utilisation of an ordinary mineral acid with which anorthosite is dissolved, and regained in a series of process steps. After the aluminium separation, precipitated calcium carbonate (PCC) is obtained as a by-product, by adding CO₂ to the solution. In this way CO₂ is stored, and - once scaled up to industrial size - it may provide an opportunity to collect and store CO₂ from, for example, a gas-fired power plant.

- The main difference between our method and previous approaches is that ours works under moderate conditions, with low temperatures and normal, atmospheric pressure. Previous attempts were based on high temperature and/or high pressure, something that has made the process more expensive and not profitable, states Mastin.

All good things come in threes
Not only does this production method give an environmental benefit, binding the CO₂ in PCC, but it also has a potential beyond just CO₂ storage, Mastin reveals.

- If we manage to produce this compound pure enough, it also provides opportunities for commercial exploitation. This material has a high degree of light reflection, among other qualities, something which makes it well suited as additive in paper, says Mastin.

The new method thereby provides the possibility of making three wishes come true at once: profitable use of mineral resources, safe CO₂ storage and valuable by-products.

However, the initial focus is on the aluminium production and CO₂ storage, stresses Mastin.

The road ahead
Presently Johann Mastin is writing the final report of the project and investigating the possibility to take out a patent on the developed process concept. IFE and Nordic Mining wish to apply for more funding from Gassnova to continue the project in a new phase in 2012. This phase will aim at clarifying technical details and determining the technical and economic feasibility of the process at large scale. If the results are positive, phase 3 will be to build a pilot plant as a next step on the road towards commercial production.

For more information on the project, see Nordic Mining’s web and press release.

2011-11-07 Text and photos by Mona Lunde Ramstad