Tiwai Toxic Tragedy?

In the course of my work a whole lot of research and interesting information never sees the light of day. I think this is one of those times where the information is worth sharing.

In the wake of the disaster in Hungary where a red toxic sludge—the by-product of processing bauxite into alumina—is causing a shit load of environmental, social, human, and economic problems, it seems prudent to see whether a similar disaster could happen here in New Zealand at Tiwai Point Aluminium Smelter.

Without bothering you with all the points here is a break down of why this kind of disaster could not happen here.

[Disclaimer: I am not a chemist and the finer details of aluminium smelting may have escaped me. Please feel free to correct me in the comments.]

• The aluminium smelter at Tiwai Point is not the same as the alumina refinery in Ajika, Hungary.
• The sludge in Hungary is a by-product of the second stage of aluminium refining—converting bauxite into alumina ore, rather than the third stage process that occurs at Tiwai Point.
• The majority of the Tiwai Point Smelter’s alumina ore is supplied from refineries in Australia. So the sludge will be there too.
• As the smelter is not an alumina ore refinery, there is no sludge by-product at Tiwai Point like that which caused the pollution in Hungary.

Therefore there are no dams or ponds which store sludge which to contaminate stuff. There are however waste by-products coming out of Tiwai.

• 186,000 tonnes of leftover refractory and carbon materials in a landfill and large sheds at Tiwai point
• There is an accumulation of waste dating back 40 years.
• This by-product waste actually has some value, and NZAS recently announced would be sending 10,000-15,000 tonnes of by-product in containers to Europe each year where the material would be used as an alternative fuel, replacing coal.
• The by-products of the smelting process primarily are, CO2, perfluorocarbons, hydrogen fluoride in gaseous form, as well as sodium and aluminium fluorides in solid form.
• Waste—for the most part—to be in solid form and would be unlikely to ‘leak’ into the environment like the reservoir in Hungary did. Gases are recaptured as are any particulates in the gases.
• The owners and operators of the smelter claim high quality safety standards at Tiwai Point [PDF].
• In 2003, NZAS achieved recognition from the International Aluminium Institute for the safest smelter in the world for a medium-sized smelter (one to three million hours worked).
• It has also been recognised in 2004 and 2006 as the safest Rio Tinto operating site in the world. Not that that means much /rolls eyes/

So I reckon that it is safe to conclude that a similar event is unlikely to happen here in NZ.

It would be good to see independent auditing of the safety processes at the plant, in terms of storage and on site contamination levels. Monitoring of the air shed around Tiwai Point and Bluff for the perfluorocarbons, hydrogen fluoride gasses and sodium and aluminium fluorides particulates should happen and the information should be public. I could not find this information, but it is likely that Rio Tinto does monitor this.