Iron ore briquettes, lump, biomass DRI may ease steel decarbonization constraints

Vale's new iron ore briquettes, along with high-grade lump ores from Canada, South Africa and Brazil, as well as biomass-based direct-reduced iron and steel production may offer alternative feedstocks and renewable processes easing constraints for steel decarbonization.

A well-founded and ongoing reliance on high-grade, low impurity iron ore pellets and electricity-intensive green hydrogen remain a bottleneck for quickly bringing on alternative lower emissions steel supplies to global buyers. Ferrous scrap market constraints also add challenges.

Even with BMW and other auto and steel end users keen to secure green steel and aluminum, the pace of investments in a cyclical steel industry and economic and infrastructure pressures requiring government involvement and support has complicated rollout.

Flexibility for DRI plants with more customized iron ore feedstock blends using new lump and briquette qualities could ease the pressure.

New DRI projects, such as a plant Petmin has been developing in Ohio using a melter for nodular pig iron grade, and new DRI modules for steel in Sweden, Spain, Germany and other countries will all likely need stable supplies of DR-grade pellets. Alternatives such as new briquette technology, once proven, could add optionality and loosen supplies.

While Vale plans to increasingly promote iron ore briquette volumes for blast furnace and DR usage, supply and demand balances in iron ore feedstocks and metallics may remain tight and in deficit, considering new DRI production plans and potential to use DRI as hot briquetted iron in blast furnaces.

Vale's briquette capacity is partly tied to converting existing pellet plants and new units at Persian Gulf iron and steel hub ventures in Saudi Arabia, the UAE and Oman, where Vale and local companies and government entities are involved. Asian steel groups JFE Steel, Baosteel, Kobe Steel and trading groups have signed up to study projects in the three countries, with further DRI plants being promoted in addition. These plans may benefit from synergies, as ironmaking investments are attracted to Persian Gulf energy supplies and carbon capture and utilization potential.

DR pellets typically are less than 2.5% silica and alumina content combined and 67%-67.5% Fe, with high metallization rates to efficiently make low gangue metallics. These alllow demanding steel qualities such as auto sheet, merchant bar, sections and wire rod to be produced.

Vale said in DRI basket tests at Midrex and Tenova HYL plants that its DR-grade briquettes achieved a 98.1% metallization rate in Midrex and 97.5% rate in HYL facilities, higher than metallization rates for DR pellets. The data surprised market participants receiving updates from the Brazilian miner at industry events in Dubai and Sweden over the past 10 days, with one pellet producer suggesting industrial trials were needed, with metallization rates likely to decline from pilot tests.

Vale's briquettes use far less energy in their production than pellets which undergo a high temperature induration process, and briquette feeds are more flexible to save on iron ore processing and waste tailings.

DRI fuel

Commercial DRI plants currently use natural gas, which is reformed to be more hydrogen intensive, while sponge iron may be produced via coal-fired rotary kilns.

New iron developer FerroSilva said May 4 that it has developed a new biomass-based process for renewable metallic iron, targeting a 50,000 mt/year plant to be completed in 2026 in Hofors, Sweden. Steel producer Ovako has an EAF at the site, along with a project to use green hydrogen for steel processing, and FerroSilva plans to sell some of its DRI to Ovako under a preliminary accord. Hot DRI charged into an EAF typically generates the most efficiency, compared with briquetting and heating cold charge.

FerroSilva expects its process to require less than a tenth of the electricity per ton of iron compared with electrolysis-based green hydrogen plants, and can generate byproducts such as liquid biogenic CO2.

"The much-discussed hydrogen-based methods for producing fossil-free sponge iron are very electricity-intensive," it said in a statement.

"Our process requires less than a tenth of the electricity per ton of sponge iron produced, as most of the energy used in our process is stored in forest residues that we gasify," said FerroSilva's Goran Nystrom.

FerroSilva has developed its process in collaboration with KTH and Chalmers, with support from Lantmannen, Sveaskog, Ovako, Uddeholm and Alleima, which was formerly Sandvik Materials Technology, it said.

Lump, direct reduction

Other projects such as Primetals' HYFOR and Boston Metal's application involve potentially bypassing pelletizing and DRI by directly reducing iron ore fines and concentrates into metallic iron for steelmaking. These remain electricity intensive, despite the energy saving potential and less pressure on hydrogen supplies.

Vale said the success of the transition to DRI depends on competitive energy costs as iron ore reductants becoming more expensive as emissions reduce. More focus is placed on hydrogen and renewable electricity, compared with coal and gas-based fuels. Capital availability and support for large-scale investments and access to high-grade iron ore quality is also crucial, customer intelligence manager Flavia Herzog said in a presentation April 25 at the International Iron Metallics Association summit.

The iron ore producer sees the steel industry moving through three stages, where operational efficiency is first targeted, including iron ore and energy optimization, before new technologies excluding green hydrogen are introduced in the blast furnace, and later a move to 100% green DRI production.

Lump's ratio in DRI plants may be tested and optimized further for new modules, with grades as high as Baffinland Iron Ore Mining's 68% Fe lump and 65% Fe from Brazil and South Africa.

Varying alkali and other chemistry and physical properties are being considered for blends with pellets, and sensitivity to EAF steelmaking. Several DRI plants already use lump, with ratios dependent on iron ore and pellet pricing differentials along with steel and scrap grades, margins, according to Middle East and North Africa region DRI market participants.