Outokumpu Stainless- Process Improvements Reduce Water Waste and Air Emissions

Outokumpu is the global leader in sustainable stainless steel. Sustainability is integrated into all our operations, activities, and decision-making across the organization. Our vision is to be the customer’s first choice in sustainable stainless steel.

Water is a primary resource in the steel-making process. It is used to cool the steel produced, as well as keep the equipment cool during production. In 2022, our Calvert site committed to reducing its water consumption in the Melt Shop by 10%. This was achieved by eliminating the use of reverse osmosis (RO) filtration. Several of the water systems in the Melt Shop require very clean water. To produce water, clean enough to use, the water is pushed through a series of membranes under high pressure which removes all dissolved solids and purifies it.

Although this process produces very clean water, it is also extremely wasteful. Approximately 25% of the water pushed through a RO system is diverted as waste to carry away the dissolved solids that were removed. Our Calvert team evaluated the water system and determined that softened make-up could be used in place of the water produced by the RO system. Softened make-up is water that is pushed through a water softener which removes just the calcium and magnesium and has no waste in this process. The softeners must be cleaned periodically but the waste for cleaning is exponentially lower than what is used in the RO process.

By switching to this different make-up source, we were able to save more than five million gallons of water in 2022 and achieved a 14% reduction in water consumption at the Melt Shop. This also provided a savings of more than 30,000 kWh because the pump was no longer needed. This project is a great example of sustainability being a core value within Outokumpu