Killing contaminants in steel scrap

Dutch Purified Metal Company (PMC) is the first company in the world capable of taking steel scrap contaminated with asbestos and Chrome-6 and turning it into a high-grade raw material. The concept will be rolled out worldwide after its launch in Europe.

PMC’s story started in 2011 when ceo Jan Henk Wijma worked at Dutch steel producer Nedstaal. On one occasion, he was offered a load of steel scrap contaminated with asbestos for half the usual price. Understandably, Nedstaal rejected the scrap as it could not be used in their process but the offer made Wijma think: ‘It should be possible to clean such scrap so that it can be used again in the steelmaking process.’

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Working with Nathalie van de Poel and Bert Bult, two colleagues at Nedstaal who are also now involved in PMC, Wijma developed an environmentally friendly and economically viable process to recycle contaminated steel scrap into a high-grade raw material for the steel industry.

Worldwide patent

They carried out feasibility studies on economic, technical and legal aspects. Every result was positive and by 2018 they had found enough backers to realise the first phase of the project. Meanwhile, they had filed for a worldwide patent on their installation and that was granted in 2014. ‘That was a surprise to us because we work with existing technologies. As the technologies were being used to build a new process, the patent was granted,’ says Wijma.

It took four years, from 2014 to 2018, to get finance for the project. The three founding partners are all shareholders, as are the Jansen Recycling Group, one of the major metal scrap recyclers in the Netherlands, several banks and government investment funds. It took another two years to build the plant, which was officially opened in September 2020.

Big market

The potential market for the recycling of contaminated steel scrap is big. Wijma estimates the Dutch market for asbestos-contaminated scrap alone at around 80 000 tonnes per year. ‘We asked demolition companies, scrap recyclers and decommissioning companies how much they handled. Most of this material comes from buildings and industrial installations but also from oil platforms, the offshore industry, high-voltage towers, ship scrapping, rail freight cars, gas transport pipes and flanges. In addition, we also recycle steel structures which have Chrome-6 in the paint.’

In many European countries, steel scrap that is contaminated with asbestos, Chrome-6 and other chemicals and heavy metals such as mercury, lead, dioxins and PCBs, is classified as hazardous waste and has to be landfilled. ‘With our new plant, there are no losers,’ Wijma explains. ‘We prevent material going to the landfill so that means less cost for society and a clean raw material for steelmakers.’

Closed process

PMC’s process, with its worldwide patent, is said to be 100% safe because it combines existing technologies. It is fully closed and automated. Contaminated steel scrap is transported to PMC by road in standard containers. After it has been though radioactivity sensor portals, the containers go through two depression lock chambers. The material is washed and taken to a Vezzani scrap shear where it is cut and pressed. It then goes to two electric induction furnaces where it is slowly placed into a smelting bath at 1 550 degrees Celsius.

During the smelting process, the contaminating substances are separated from the steel. The structure of the asbestos fibre is destroyed and converted into non-toxic components of water, silicon dioxide and magnesium oxide. They float as slag on the smelt and are removed for secondary use as a construction material.

Other harmful substances such as organic compounds are captured or neutralised in a state-of-the-art flue gas cleaning system and bound with active coal. The result of the melting process is 2% slag, 2% flue gas and 96% clean steel scrap. 

When the steel is molten, it is transported to the casting machine and analysis determines the chemical composition of the liquid smelt bath. In the casting machine, a batch of 20 tonnes of liquid steel is transformed into ‘purified metal blocks’, each of seven or eight kilos, which are sold to foundries and electric arc furnace mills across Europe.

The PMC process is clean and environmentally friendly. When compared with plants that make steel from iron ore, the CO2 emissions in OMC’s process are said to be about half. This results in a reduction of CO2 emissions of 150 000 tonnes per year, approximately equal to the annual emissions of 45 000 passenger cars.

International ambitions

PMC currently recycles material from the Netherlands, Germany and Belgium. But there is also interest from Australia and the USA. The company has had inquiries from the city authorities in New York to see if it can process steel from rail freight cars held in storage because they contain asbestos and Chrome-6.

‘There is room for five plants in Europe and we are currently investigating a plant in the Leipzig area in Germany,’ says Wijma, ‘We have ambitions to prevent contaminated steel going to the landfill worldwide, so who knows what the future has in store for us?’