Samarco and red mud

On November 5 this year, a tailings dam at an iron ore operation in Brazil collapsed. That sent large volumes of water and sludge into a second dam, which also collapsed. The resulting flood saw millions of litres flow into a nearby village, claiming the lives of 13 people, with 6 others still missing. The operation is called Samarco and is owned 50% each by BHP Billiton and Vale.

A tragedy such as this is a sad loss of life. It can also serve as a reminder to alumina refineries around the world to review their red mud reservoirs for soundness and safety.

The process of converting bauxite into alumina generates a lot of so-called red mud. There are very few uses for this material. A small amount is used in road making, or in concrete. But by far the biggest outcome is for it to be stored in ponds. (At one stage, I recall French Canadian company Orbite said they could extract more alumina from the waste, but I am not aware of any commercial operation.)

The world produces about 55 million tonnes of aluminium per year, so that means at least 250 million tonnes of bauxite is going into alumina refineries, and about half is going into red mud ponds. That’s in one year - combine all the years of alumina refining and you end up with a very large amount of red mud stored in ponds around the world.

I know from my discussions with senior people inside the International Aluminium Institute that the industry takes a very serious and responsible attitude towards the management and control of red mud and the ponds that house the mud. The industry got a wake up call in 2010, when a red mud pond in Hungary collapsed. That incident cost the lives of 10 people. The pond and the factory that produced the red mud were not directly associated with aluminium production, but the wake up call was heeded in any case.

But it’s not just today’s enlightened companies and their management who have responsibility. Alumina refining has been going on for over 100 years. Although the mud will eventually dry out, in the meantime those ponds have to be maintained. Who does that if a company has gone bankrupt, exited the industry or moved to another country? Even if someone comes up with a new sustainable use for the material, there’s still a very large number of existing ponds in many corners of the world that someone needs to be maintaining. The Hungary incident partly was put down to very heavy rains in the months prior. No area is safe from abnormal weather conditions, but the walls of those ponds must be strong enough year after year.

Are all companies involved in producing alumina equally enlightened? Although I have no evidence, I worry about whether every alumina refinery in China has adequate protection and maintenance programs in place. China is the world’s largest producer of alumina, making it also the world’s largest producer of red mud. China will produce about 55 million tonnes of alumina this year, with a lot of the feedstock coming from low yield areas such as Malaysia. That means at least as much red mud produced - and stored for years to come.