Challenge details:

Gas Cleaning Plants (GCP) in steel manufacturing facilities generate a sludge that contains high levels of iron oxides and has traditionally served as a suitable raw material for pellet making, which in turn provides feedstock for blast furnaces. However, elevated zinc content in this sludge presents a major operational challenge. Zinc entering the blast furnace circuit can damage refractory linings and therefore disrupt furnace performance. In addition to process concerns, the zinc present in the sludge categorizes it as hazardous waste, making conventional disposal methods difficult. The plant currently produces approximately 40 tonnes of this sludge each day.

We seek technologies capable of recovering zinc from the sludge so that it can be safely and effectively reintroduced into the pellet‑making process. Any solution must be compatible with the sludge's typical composition—more than 20% carbon, 6-10% iron, and measurable quantities of manganese, calcium, and other heavy metals—while reducing its hazardous characteristics. Technology providers are expected to deliver end‑to‑end solutions, including feed preparation, zinc recovery processes, and downstream offtake arrangements. Proposed approaches should ensure long‑term operational feasibility and support the company's broader circular‑materials strategy.