Iron Cycle 2019 at IOM3

Materials World magazine
,
10 May 2019

The Iron Cycle (Fe150) conference called upon all ferrous mining stakeholders to work together to help maintain a sustainable industry.

Collaboration between stakeholders and colleagues in order to achieve a sustainable iron and steel industry was the underlying theme of The Iron Cycle (Fe 150) conference. Held on 22 March at the Institute’s London office, the event celebrated 150 years since the formation of the group’s earliest predecessor, the Iron and Steel Institute (ISI). The speakers offered real-life examples of how to address current challenges in the industry, such as reducing carbon emissions, increasing profitability, maximising the lifecycle of materials, and minimising mistakes.

Minerals Processing & Extractive Metallurgy Board Chair, Tony Francis, summed up the conference as doing ‘exactly what it said on the box. It provided a set of presentations by eminent experts covering the complete iron cycle from exploration, mining and processing to end-use and recycling, taking in sustainability on the journey. This truly was a tribute to the material that made the modern world’.

University of Cambridge Head of Materials Chemistry in the Department of Materials Science, Professor Vasant Kumar, said the steel industry emitted 7.5% of total global greenhouse gas emissions and 25% of total industrial greenhouse gas emissions.

Therefore, choosing smarter production methods for reducing carbon creation during processing could help reduce the overall emissions footprint of the iron cycle. Kumar noted that about 40% of steel produced was from scrap melting and refining in an electric arc furnace (EAC).

‘EAC using scrap is significantly less energy intensive [that other methods], however, if electricity is produced from renewable and non-fossil fuel sources, then the net carbon emission is greatly decreased,’ he said.

The Institute’s Sustainable Development Group Chair, Louis Brimacombe, said a report by the Intergovernmental Panel on Climate Change on emission targets and the necessity to achieve a low-carbon society would demand that the industry revisit the challenge of reducing carbon from primary and secondary production processes and increase the focus on improving material efficiency across the product lifecycle and the steel supply chain.

Reused casings extend lifecycle

Recycling the material from decomissioned or abandoned oil wells is an effective way of extending the lifecycle of steel casings in particular. The materials benefitted other industries, including resellers who could offer former steel casing pipes for construction projects. Some wells, particularly through North America, have reused the casings from previous sites into new ones.

Well Decom Ltd Managing Director, Stephen Jewell, said it would cost £60bln to decommission all the infrastructure including platforms, subsea facilities and wells in the North Sea. Wells alone accounted for £30bln of this.

Jewell said the use and reuse of oil pipes differed across regions. ‘In the UK offshore, we tend to use casing pipe with premium connections and metal-to-metal sealing faces. These can be compromised by repeated screwing and unscrewing of the connection, leading to an increased risk of leaks if re-used,’ he explained.

‘UK wells are very expensive to construct and so we would avoid any risk of leakage. In the US onshore, they would use ‘used’ premium threaded casing where premium connections are not required, thus creating a secondary market for re-using the casing there.’

He cited The Event Complex Aberdeen and Montrose Port redevelopment, both in Scotland, as sites where steel casing pipes had been reused for other purposes in the UK (see page 14).

British Metals Recycling Association spokesperson Antonia Grey said, although there is risk in not knowing what the condition of a steel pipe might be until it was brought to shore, metal recyclers would still be drawn to such material due to the volume of it and the drive towards achieving circularity in the area of oil and gas decommissioning.

Flowsheets for tailings management

Work flowsheets that incorporate methodology for dry stacking and dry processing, and for water shortages, should be required for new mining projects, according to Tetra Tech consultant metallurgistDr Arun Vathavooran.

His view follows news of a tailings dam collapse near Brumadinho in Minas Gerais state, Brazil, in January, when 142 people died and 194 were missing. The dam failure released red iron ore waste into the local area, which raised concerns of contamination.

He said there had been 258 recorded TMF failures globally since 1960.

Vathavooran said the advantages of dry processing included no conventional wet tailings management facility (TMF), a smaller site footprint, a potential increase in mine life, and lower energy consumption. However the disadvantages included dust due to dry grinding, and coarse separation was not possible.

According to Vathavooran, dry stacking offered water recovery reuse and no need for conventional wet TMF, but there were higher dewatering capacity requirements, in particular filtration capacity, and the filtration performance was subject to changes in ore minerals.

Changing times

Iron and Steel Society Vice Chair, Dr Laura Baker, said the group was founded primarily as a ‘protectionist society’.

‘The original members were British Victorian ironmasters who were worried about competition from Europe,’ she said. ‘They soon realised the benefits obtained by the open exchange of information, and rapidly developed into one of the leading learned societies of the time.’

Baker said history was repeating itself in that the Institute could offer a platform for discussion and unity within the industry as it strives to find sustainable ways to make iron and steel.

‘In 1869, the industry was divided as to the best technology for iron and steelmaking. We find ourselves there again. And with global politics challenging existing trade relations, this is the opportunity for us to unite as a UK steel industry.’