Aluminium and aluminium products supplier Hydro (Norway) and materials characterisation company Malvern Instruments will jointly present a paper at Relpowflo IV in Tromso, Norway, 10-12 June 2008
The presentation - 'Investigation into the segregation of alumina on board ships and in the silos' - describes how Insitec Voyager, Malvern's mobile, on-line particle size analyser, is being used to characterize the alumina feed for Hydro's aluminium primary production.
Voyager has enabled Hydro to investigate segregation during transport and storage, and the impact this has on the electrolysis process.
Alumina is delivered, by ship, from around the world.
Loads are generally between 10,000 and 50,000 tonnes.
Although there are certificates of particle size, alumina is extremely prone to segregation, hence this feed can be quite variable.
"Insitec Voyager has allowed us to increase the frequency of analysis by several orders of magnitude.
"Now we can see how segregation impacts the feed with a higher resolution, and how accumulated fines negatively affect alumina transport and the efficiency of the electrolysis cells".
Analysis is now completed rapidly, at site rather than at a remote lab, and at a number of locations since the instrument is easily moved to the required sampling point.
Voyager is a fully automated laser diffraction system with no moving parts, suitable for dry streams with particles in the size range 0.1 to 1000 microns.
It analyses even highly concentrated streams with no loss of accuracy - an important feature for this application.
In future, Hydro seeks to investigate the further potential of the Voyager, employing it as a field laboratory facility to make possible the analysis of thousands of samples.
By introducing at-site analysis during larger campaigns, analysis will become less expensive, with the results available much more quickly.
