Fortescue’s Iron Bridge: a future forged in green metals

Fortescue has found its stride at its Iron Bridge project in WA, the company’s first foray into magnetite operations.

Now, the company is looking to ramp up the project’s high grade magnetite production to nameplate capacity, ensuring it stands as a testament to what can be achieved in a net zero future.

The Australian Mining Review speaks with Fortescue (ASX: FMG) Iron Bridge operations director Graham Howard about the unique features of Iron Bridge, renewable energy initiatives and the company’s development plans.

AMR: Iron Bridge signifies Fortescue’s entry into the high-grade segment of the iron ore market, providing an enhanced product range while also increasing annual production and shipping capacity. Will we see more resources pumped into green iron and magnetite production?

GH: We are all in on green hydrogen. Technology is improving at rapid speed which will see the cost of green hydrogen come down. We maintain a large portfolio of projects which show significant potential for decarbonisation and economic growth. These will progress when power prices fall sufficiently to bring them to economic viability and the world demand for hydrogen increases.

We think the biggest and most promising green metals opportunity for Australia lies in the transition to producing green iron at scale in the Pilbara and we see Iron Bridge as playing a role in that. The cost of green energy is still a significant challenge here in Australia and a huge barrier to getting a green metal industry off the ground. We’re actively engaging with all levels of government to ensure the support mechanisms needed to establish this new green industry are implemented.

AMR: Strong growth in global steel capacity combined with sluggish demand could warn oversupply. Does investment into high-grade iron via magnetite mitigate some of this risk?

GH: High grade products such as Iron Bridge concentrate allows Fortescue to meet the evolving future needs of steelmakers. We continue to see significant interest in the market for Iron Bridge concentrate and we remain absolutely focused on its safe and efficient ramp up.

AMR: What makes Iron Bridge Fortescue’s most innovative iron ore project yet?

GH: The Iron Bridge value chain is unique compared to our hematite operations and has a processing design that is different to every other magnetite producer. The process, which is subject of several patents, is designed to reduce energy consumption and water use.

A few of our most impressive technologies at Iron Bridge include:

• 20 dry magnetic drum separators are used as the first stage of beneficiation, treating 62.5mtpa of ore-processing facility (OPF) feed
• 12 high pressure grinding rolls with a total installed power of 93MW which reduce the 52mt dry magnetic concentrate down to 80µm size
• The high pressure grinding rolls operate in closed circuit with 12 massive 2-stage air classifiers, which enable this classification down to 80µm without introducing any water
• 10 high intensity grinding stirred tower mills, with a total installed power of 50MW. These mills provide size reduction down to 35µm in open circuit with high efficiency

Additionally, the process flow has unique design elements throughout it to reduce electrical power and water usage. Electrical power is reduced by the extensive use of dry grinding using high pressure grinding rolls. We reduce the product size down to 80µm while it remains dry by using high pressure grinding rolls and two stages of air classification. This uses less power than traditional magnetite comminution pathways such as semi-autogenous (SAG) and ball milling as well as reducing water usage. Water usage is further reduced due to the 10 Lyons Flow Control Unit utilised to deslime the concentrate in the wet processing plant.

AMR: Iron Bridge produces a wet concentrate product which is transported to Port Hedland through a 135km specialist slurry pipeline where dewatering and materials handling occurs. How intensive is the processing pathway for products coming out of Iron Bridge?

GH: The 135km specialist slurry pipeline is in full operation and has delivered more than 3mt of processed magnetite to our Concentrate Handling Facility in Port Hedland.

Processing magnetite is significantly more intense than hematite which is why our processing plant design is a patented process and has been specifically designed to cost effectively achieve high iron ore recovery while minimising energy and water usage.

The Iron Bridge OPF is physically larger and uses more plant and equipment than any of our hematite processing plants. The most notable aspect of this design is the use of dry processing to achieve a very fine sized material.

AMR: Fortescue’s 2025 goal is to ramp up Iron Bridge high grade magnetite production to nameplate capacity. How is Fortescue achieving this and how is it progressing on this goal?

GH: Fortescue has had its best ever start to a financial year with record first quarter iron ore shipments of 47.7mt, which included 1.6mt from Iron Bridge. We also achieved two major production milestones from Iron Bridge with 2mt of magnetite shipped since first production in 2023. Our shipment on September 17, of 206kt was also WA’s largest ever shipment of magnetite — a huge effort by the Fortescue team.

Our focus is now on safely ramping up our Iron Bridge operations to full production capacity.

AMR: Fortescue has reported that Iron Bridge is the largest contributor to its overall emissions reduction in the near term. How will Iron Bridge and magnetite help Fortescue reach its sustainability goals?

GH: Increasing the green power we have in our energy system — such as the recent commissioning of a 100MW solar farm at North Star Junction (NSJ) — helps us to reduce our emissions profile while we are progressively decarbonising our mobile fleet. As we work towards our Real Zero emissions target by 2030, our emissions profile will rise as our Iron Bridge operations ramp up. Iron Bridge represents a large portion of our stationary energy demand in the future state, so we also see huge value in accelerating the deployment of green power in the Pilbara to meet this demand.

Additionally, our magnetite product allows our customers to produce fewer carbon emissions in the steelmaking process, so decarbonising our Iron Bridge operations will allow us to provide our customers with an attractive product for green metal production.

AMR: What is the progress on getting North Star and Iron Bridge connected? Are there plans to increase the renewable fraction at Iron Bridge?

GH: We have recently commissioned our new 100MW solar farm at NSJ. First construction commenced in October 2022, which means it was just under two years between first construction and full commissioning. NSJ Solar is the first of many solar projects we will build as part of our journey to decarbonisation and will provide an immediate reduction in carbon emissions by reducing gas consumption from the Solomon Power Station, providing Iron Bridge with more than 30% of forecast FY25 energy demand. Iron Bridge renewable power penetration will increase as we deploy more green power projects in the Pilbara, aligned with our 2030 Real Zero target.

AMR: With other big names like Atlas Iron and Hancock Prospecting, where does Fortescue fit in and how is it competitively positioned in Pilbara iron ore?

GH: For us, our point of difference is our pivot to green metal where we are already seeing strong demand globally.

Earlier this year we started building our pilot Green Metal Project — the first step in producing green iron metal at a commercial scale.

We’ve also announced the proposed development of a fully integrated green iron supply chain between Australia and China with the ultimate ambition being to provide 100mtpa of green iron to China, eliminating over 200mtpa of carbon emissions.

This would bring together green sustainable mining, large-scale renewable power and green hydrogen to produce green iron metal.