Bauxite - Alumina - Aluminium

"Aluminium oxide (alumina) is extracted from bauxite in a refinery. Alumina is then used to produce primary aluminium."

"4-7 metric tons of bauxite = 2 metric tons of alumina = 1 metric ton of aluminium."

"While much of the mining sector’s focus has been on the iron ore market, bauxite has been quietly moving up the ranks as a quiet achiever and Australian companies are poised to take advantage.

Last year the commodity’s value reached a peak of $US73.80. The underlying cause of the price rise comes down to the ban on Indonesian bauxite exports, which resulted in China’s stockpiles being steadily depleted."

Snitt 5,5 tonn Bauxite gir 2  tonn alumina. Regner man med $50/tonn for bauxitt, koster råvarene for å produsere 1 tonn alumina $137,5. (kurs USD->NOK= 8,22 den 21.08.2015). 1130 kroner.

"Red mud is a side-product of the Bayer process, the principal means of refining bauxite en route to alumina. The resulting alumina is the raw material for producing aluminium by the Hall–Héroult process.[2] A typical bauxite plant produces one to two times as much red mud as alumina. This ratio is dependent on the type of bauxite used in the refining process."

"Red mud or red sludge is a waste product generated in the industrial production of aluminium. With about 77 million tons of this hazardous material produced annually, red mud is one of the most important disposal problems in the mining industry."

Anortosittforekomsten i Gudvangen er i størrelsesorden 500 millioner tonn og inneholder ca. 30% alumina. Fremstillingsprosessen etterlater ingen uønskede restprodukter. Biprodukter fra fremstillingsprosessen er kalsiumkarbonat (ved CO₂-binding) og silisiumoksid.

Det er estmert at man vil binde 110000 tonn CO₂ pr. 1 million tonn anortositt. Sammenlignet med fremstilling av bauxitt, vil mao. den nye fremstillingsmetoden for alumina av anortositt gi et mye lavere miljøavtrykk.

Enova kan gi støtte til pilotanlegg (ref. Hydro Karmøy pilot) for prosesser som kan gi en vesentlig miljøforbedring ift. dagens alternativer.