Swerea MEFOS has been engaged in a large number of green technology projects, from recovery of valuables from wastes to green energy production using metallurgical concepts.
The total budget in this field is more than €30M (excluding the ULCOS project) in the past 10 years, with 90% of these projects financed by international companies and institutions.
Decreasing carbon dioxide emissions is a global priority. The European steel and mining industries have joined forces in ULCOS programme. One approach of the programme is the development of the top-gas-recycling blast furnace process, partly financed by the EU Research Fund for Coal and Steel (RFCS).
So far, three versions of the topgas- recycling blast furnace process have been tested in the LKAB experimental blast furnace. Two versions were tested in the first trial, autumn 2007. One of these was further explored during recent trials, together with a third version. The best version will be verified in upcoming trials.
The experimental blast furnace is, from an operational point of view, equipped like a modern industrial furnace. It is integrated with the equipment for CO2 removal and the operation is controlled and evaluated through sophisticated measurements and material sampling. This offers the opportunity to explore the new process in comparison with conventional blast furnace operations. Various raw materials can also be compared and tested for the new process.
Swerea MEFOS is the leader of the equipment modification at the LKAB experimental blast furnace and the last few months have been busy with design, construction, installation, preparing for the recently completed trial campaign.
Researchers from project partners representing the European steel industry have spent several weeks in Luleå. The plant is managed and operated by staff from Swerea MEFOS.
Under the leadership of LKAB, the trials and processes are managed by onsite researchers through evaluation of process data. During daily process meetings, results are discussed and decisions made about process control and how to move to the next step.
Improved equipment and a well-designed trial plan contribute to this success.
The knowledge achieved in terms of equipment and operational experience will be used to transfer results to industrial scale. Engineers from Swerea MEFOS can assist the actual plant in the equipment design, installation and operation start up.
Less carbon dioxide
Its VILD research programme – Vanadium in LD-slag – is ongoing. This is an eight-year project with a total budget of about €5M (2005– 2012) financed by The Foundation for Strategic Environmental Research (MISTRA) and Nordic steel industries such as SSAB, Ruukki, LKAB and Merox.
The environmental potential includes savings of 1Mt of carbon dioxide emissions and 2TWh of energy at SSAB alone.
SSAB and Ruukki are currently running their blast furnaces solely with LKAB pellets containing 0.2% V2O5. After reduction in the blast furnace and subsequent decarburization, the oxidised vanadium ends up in the LD slag, with a vanadium content of 2.2–2.8%.
The production of LD-slag in Sweden alone is 350–400kt/y. The coarser fraction is recycled to the blast furnace to fully use the excess CaO in the slag. The recycling rate is limited by the tolerance for phosphorous and vanadium accumulation.
The fine fraction, about half the production, is disposed and stored. Disintegration of the slag and high vanadium content are the main problems for external use of the slag. The total vanadium content in the Swedish LD-slag disposed is about 5000t With the current vanadium price, this corresponds to a total value of €100M lost in the slag yards each year.
The VILD concept aims at two final products, a well-reduced and modified slag product ready for external use and a standard FeV for use in the steel and foundry industry. The VILD concept consists of three steps:
Step 1 Hot slag reduction aiming at a high vanadium recovery and a slag product for external use or internal circulation to the blast furnace.
Step 2 Removal of phosphorus from the metal obtained in Step 1.
Step 3: Final production of a standard FeV product.
Swerea MEFOS has verified the concept with 150kg and 4t trials at Swerea MEFOS and 4–10t trials at industrial scale at SSAB during Phase I. Results from these initial trials show that the hot slag reduction step is feasible and the vanadium content can be reduced to well below 0.1% which is set as the limit for possible use in cement production.
In the second phase (2009– 2012), the industrial trials in slag reduction and treatment will be intensified and basic studies and evaluation of the V-bearing slag system continued. At the end of the project, an industrial concept will be presented.
ULCOS stands for Ultra–Low Carbon Dioxide (CO2) Steelmaking. It is a consortium of 48 European companies and organisations from 15 European countries that have launched a cooperative research and development initiative to enable drastic reduction in carbon dioxide emissions from steel production.
The consortium consists of all major EU steel companies, energy and engineering partners, and research institutes and universities and is supported by the European commission. The aim of the ULCOS programme is to reduce the carbon dioxide emissions of today’s best practices by at least 50 %.