Landfilling is out of fashion, but what to do when there is no alternative? For asbestos-contaminated steel scrap, this alternative is now coming into view.
The use of asbestos has been banned in the Netherlands since 1 July 1993. So far, asbestos released from demolition activities is still dumped under controlled conditions. Funding is in place for PMC(Purified Metal Company) to build a plant to recycle asbestos-contaminated steel scrap. The scrap can come from e.g. dismantled trains, ships, oil rigs, etc. Planned capacity is 150,000 tonnes of scrap per year, enough for the Netherlands and Belgium combined.
The scrap will be melted in two parallel induction furnaces, each with a capacity of 40 tonnes, a maximum power of 16 MW and an expected electricity consumption of 672 kWh/t. The advantages of induction furnaces are the high degree of temperature and process control, high melting rate and the ability to melt materials with a "hot heel", the principle that some of the material remains in the pan to maintain the conditions of a liquid-steel bath. The scrap is dumped into this hot heel (temperature 1500 - 1700°C), where asbestos is converted into water, silica and magnesium oxide(not manganese oxide, as the EIA states). The asbestos fibres disintegrate between 700°C (chrysotile) and 1,050°C (other types).
One other company in Europe, Inertam in Bordeaux, thermally processes asbestos and asbestos-containing waste on a commercial scale. Vitrification takes place there in a plasma, with higher electricity consumption and higher processing costs.
