New technology for cyanide removal and emission reduction in the steel industry

Cyanide is present in coke oven gas and blast furnace gas, which are used as fuel gases in various process installations. Upon combustion in e.g. the hot blast system, cyanide contributes to additional NO_x formation. This directly increases emissions and pressure on the available NO_x allowance and indirectly leads to unnecessarily high fuel costs. In addition, elevated NO_x levels accelerate stress corrosion, which is an unacceptable risk in pressure vessels.

Cyanide removal from fuel gas

During development, Ferr–Tech and Danieli Corus evaluated two routes: treating the fuel gas or treating the flue gas. Since the flue gas stream is much larger in volume and requires more complex installations, the partners selected a treatment that removes cyanide directly from the fuel gas. In this treatment, FerSol^® is dosed into a packed column and removes cyanide within seconds.

Sina Samimi Sedeh, Head of Innovation at Ferr–Tech: “The testing phase required perseverance, but it provided valuable insights. By refining the design step by step, we arrived at a solution that performs reliably in practice.”

More than 99% cyanide removal and a circular residual stream

After laboratory validation, the module was extensively tested in the field. Results show that more than 99% of cyanide components are removed, without the formation of harmful substances.Peter Klut, Manager Technology at Danieli Corus: “This powerful, green oxidant breaks down cyanide quickly and completely, without the side reactions seen with traditional chemical oxidants. It prevents corrosion issues and reduces emissions. A promising step forward.”

Treatment with FerSol^® produces clean water, a feed component for the production of new FerSol^®, and an iron hydroxide sludge stream. The sludge contains no cyanide and can be reused as a raw material in the steelmaking process.

Significant step for the steel industry

Richard Willemsen, Business Development Manager at Danieli Corus, sees this as a major step for the sector: “Steel producers are looking for practical ways to reduce fuel NO_x, creating room for the additional thermal NO_x that is connected to operating at higher flame temperatures, which lowers overall CO₂ emissions. This technology contributes to achieving these goals while reducing operational costs, because it lowers fuel consumption.” This solution can be integrated relatively easily into existing installations.

Strategic partnership

Ferr–Tech and Danieli Corus have been working together for some time on applications for FerSol^® in the steel industry. The combination of technology and market know-how accelerates the move toward practical implementation.Richard Bruins, CEO of Ferr–Tech: “The collaboration comes very naturally. We provide FerSol^® and the technology around it, while Danieli Corus has fundamental knowledge of the steel industry. Together we develop applications that already show tangible results.”