SteelPhalt: Imanol Pradales, the president of basque country, inaugurates the SteelPhalt sustainable asphalt plant in Murga

• The plant will valorize steel aggregates from Basque steelworks and transform them into sustainable asphalt with a low carbon footprint.
• The new facility has the capacity to process 190,000 tonnes annually—up to 50% of all steel slag produced in the Basque Country—boosting the circular economy.
• The project involved an investment of over €13 million, spans 30,000 m², and in this first phase employs 15 workers.
• SteelPhalt™, a company under Harsco Environmental, has chosen the Basque Country as the global hub to internationalize its pioneering manufacturing model, previously only operating in the UK.

SteelPhalt, part of Harsco Environmental, has chosen the Basque Country as the first global location to expand its pioneering model of sustainable asphalt production, previously implemented exclusively in the United Kingdom. Today, Lehendakari Imanol Pradales officially inaugurated the first and only plant in Spain producing sustainable asphalt derived from steelmaking slag. He was joined by Ramiro González, General Deputy of Álava; Mikel Jauregi, Minister for Industry, Energy Transition and Sustainability of the Basque Government; Saray Zárate, Deputy for Economic Development and Innovation; Marisol Garmendia, Spanish Government Delegate in the Basque Country; Alejandro Dorado, Commissioner for Circular Economy for Ecological Transition and Demographic Challenge; Stephane Boissinot, President of Harsco European Operations; and Mikel Barandalla, Operations Director of Harsco Southern Europe & SteelPhalt.

The plant consists of two processes that make this application unique: the valorization of steel aggregates and their subsequent use in producing sustainable asphalt. The project represents an investment of over €13 million and spans 30,000 m², of which 15,000 m² will house all the steel aggregate valorization processes under one roof. The final mixing and encapsulation processes for the eco-asphalt will take place outside. The plant also includes a fully equipped 100 m² in-house laboratory for quality control and I+D project development. In this initial phase, 15 direct jobs have been created, in addition to significant indirect employment in the Airaldea area, including goods transport, industrial supplies, maintenance services, and a boost to local hospitality businesses.

SteelPhalt will use waste generated by the Basque steel industry. Through its valorization process, these materials will be converted into specially produced steel aggregates for asphalt manufacturing, resulting in a sustainable, high-performance asphalt.

The new SteelPhalt facility can handle 190,000 tonnes annually—up to 50% of all steel aggregates generated by steelworks in the Basque Country—significantly advancing the circular economy.

Environmental Benefits

The asphalt produced at the SteelPhalt plant offers numerous environmental and technical advantages. Unlike conventional asphalt, which heavily depends on aggregates from quarries, SteelPhalt uses steel aggregates, a by-product of the steel industry. This process enables the reuse of materials, reduces natural resource extraction, and minimizes the environmental impact associated with raw material mining and transport.

From an environmental standpoint, the resulting asphalt contains up to 95% recycled material, significantly lowering the carbon footprint of construction materials—by an estimated 50%.

From a technical perspective, the structure of the steel aggregate not only enhances the sustainability of the product but also allows SteelPhalt to offer a more durable and resilient option, potentially extending the lifespan of road surfaces by up to 20%.

This sustainable asphalt will be primarily used in the regional road network maintained by the Basque Government, Provincial Councils, and local municipalities. It may also be used in the construction of bike lanes, parking lots, velodromes, and other high-performance pavement projects with a sustainable resource-use focus.

Boosting the Circular Economy

The project for sustainable asphalt production using steel slag aggregates from carbon and stainless steel is a recipient of a grant from the Spanish Ministry for Ecological Transition and the Demographic Challenge (MITECO), under the 2022 call for circular economy promotion in business. This is part of the Recovery, Transformation and Resilience Plan (PRTR), funded by the European Union – NextGenerationEU.

The company received €2.4 million in subsidies. The goal of this funding is to support projects that substantially enhance the sustainability and circularity of industrial and business processes—reducing environmental impacts from resource extraction and waste generation—while improving industrial competitiveness and innovation within the framework of the circular economy.

First Plant Outside the United Kingdom

SteelPhalt has operated successfully in the UK since the 1960s, and the Álava plant in Murga marks its first expansion outside the country. The strong presence of steelmaking companies, institutional support, and high level of economic development were key factors in prioritizing the Basque Country for investment, following the multinational’s 2022 decision to expand globally.

Moreover, SteelPhalt Euskadi will be the first and only company to have a steel aggregate valorization plant integrated within the same facility that produces the sustainable asphalt. It will also be the only company to consistently produce eco-asphalt using up to 95% steel aggregate, meaning 100% of its aggregates are recycled.

About SteelPhalt

SteelPhalt is a company specializing in the production of sustainable asphalt solutions using recycled steel slag as the main component. Operating successfully in the UK since the early 1960s, SteelPhalt, as a division of Harsco Environmental, works closely with the steel industry to source steel slag in an environmentally friendly manner and convert it into products for eco-asphalt manufacturing.

About Harsco Environmental

Harsco Environmental, a division of Enviri Corporation, is the world’s largest and most comprehensive provider of on-site material processing and environmental services for the global metals industry, operating at over 130 customer sites across more than 32 countries. Harsco Environmental is a technology partner that enables cleaner, more efficient metal production, offering customers economically and environmentally sustainable solutions for by-product processing and reuse.