Displaying items by tag: ground granulated blast furnace slag

Ecocem announced this week that it has achieved certification in the US for its ACT low-carbon cement technology. This follows CRH’s agreement to buy US-based Eco Material Technologies, a supplier of supplementary cementitious materials (SCM), which was revealed in late July 2025. These moves and others mark a flurry of activity by various companies in the US SCM sector in recent months.

Donal O’Riain, the founder and managing director of Ireland-based Ecocem, underlined the importance of certification in North America when he said that “The US is one of the largest cement markets in the world, and this certification will support integration into existing supply chains and offers a pathway for the sector to rapidly decarbonise.” The country imported just under a fifth, 19Mt, of its Portland and blended cement in 2024 according to the United States Geological Survey (USGS).

Ecocem started out as a manufacturer of cements made using ground granulated blast furnace slag (GGBS), a SCM, in the early 2000s. Its ACT technology was formally announced in 2022. It is described as a process that can make cements using “available fillers like limestone and local SCMs.” It is currently scheduled for a commercial launch in 2026, starting in France. In the US it is planning to build a terminal and mill at the Port of Los Angeles in California. This follows a previous attempt to build a slag grinding plant, also in California, in the 2010s.

CRH, another cement company with strong links to Ireland incidentally, said on 29 July 2025 that it had agreed to acquire Eco Material for US$2.1bn. The latter operates a network of fly ash, pozzolan, synthetic gypsum and green cement operations. It partners with electricity generators to process about 7Mt/yr of fly ash and 3Mt/yr of synthetic gypsum and other materials. As CRH’s CEO Jim Mintern put it, “this transaction secures the long-term supply of critical materials for future growth and puts CRH at the forefront of the transition to next generation cement and concrete.” The deal is expected to close by the end of 2025. In separate comments to analysts Mintern added that he expects the market for SCMs to double in the US by 2050.

Other players have also been busy in recent months. Amrize, for example, noted in its financial results for the second quarter of 2025 that it had broken ground on a new fly ash beneficiation facility in Virginia in the reporting period. Last week, Graymont and Fortera signed an agreement to produce Fortera’s ReAct low-carbon cement product by using Graymont’s existing lime production operations. Fortera runs a plant in Redding, California that takes captured CO₂ from the adjacent CalPortland cement plant and uses it to manufacture its own proprietary SCM. Back in April 2025 Buzzi Unicem said that it had partnered with Queens Carbon to produce a novel cement and SCM. The start-up was intending to build a 2000t/yr demonstration plant at Buzzi Unicem’s cement plant in Stockertown, Pennsylvania.

The backdrop to all of this attention on SCMs in the US are the cost of cement and sustainability. Using more SCMs reduces clinker usage in cement and it can reduce the cost. At the same time reducing the amount of clinker used decreases the amount of CO₂ emissions. So, for example, Ecocem says that its ACT technology can reduce CO₂ emissions by up to 70% compared to conventional cement.

A report by Mckinsey on SCMs in the autumn of 2024 reckoned that growth in the cement market in North America was expected to be ‘robust’ in the next 15 years to 2050. However, the sector faces material, particularly clinker, and labour shortages. Enter SCMs! It went on to assert that much of the available stocks of GGBS and fly ash in the country are effectively used. Yet, traditional industrial SCMs such as GGBS, fly ash and limestone are anticipated to be available for longer than in Europe as industries such as steel manufacture and electricity generation will take longer to decarbonise. Hence companies such as Ecocem are preparing to import them, ones like CRH are cornering existing stocks and others such as Fortera and Queens Carbon are working on creating their own ‘virgin’ sources. At the same time the American Cement Association has been promoting the use of Portland Limestone Cement in the country.

All this helps to explain the interest in SCMs in the US right now. It’s a busy moment.

Sweden: Cemvision has developed a patent-pending beneficiation process to upcycle electric arc furnace (EAF) and basic oxygen furnace (BOF) slags into high-performance supplementary cementitious material (SCM), while recovering valuable metals.

Third-party testing found the material performs as well as or better than ground granulated blast-furnace slag (GGBS). Cemvision recovers 99% of the iron oxide content from EAF slag for reuse in steelmaking, as well as other metals like chromium.

The output will support Cemvision’s Re-Ment Massive and Rapid products as clinker-replacing SCMs. The process was piloted with metallurgical research institute Swerim.

Cemvision CEO Oscar Hållén said “This is a game-changer not only for the cement industry but for steel producers as well. Our process enables high-performing cement products from materials that would otherwise be treated as waste. With this innovation, we're proving that decarbonisation and circularity can go hand in hand, and at scale.”

Indonesia: Siam Cement Group (SCG) subsidiary PT Semen Jawa used 24,000t of alternative raw materials in its cement production during the first quarter of 2024. These circular materials included bottom ash, fly ash and slag. This corresponds to 3% of its total raw material usage. Meanwhile, the producer co-processed 15,000t of alternative fuel (AF) during the quarter, representing a 20% AF substitution rate.

SCG Indonesia director Warit Jintanawan said that the developments "Not only enhance production efficiency, but also significantly reduces our carbon footprint. This is a testament to SCG's commitment to supporting Indonesia's climate goals, aiming to reduce greenhouse gas emissions by 32%, aligned with Enhanced National Determined Contributions."

UK: Heidelberg Materials UK has received certification to the revised BES 6001 standard across its entire business. The Framework Standard for Responsible Sourcing of Construction Products, version 4.0:2023, emphasises sustainable procurement and supply chain engagement, alongside environmental aspects such as biodiversity. It covers products including cement, ground granulated blast furnace slag (GGBFS) and concrete. The producer says that this will help it to secure additional green building certification schemes credits.

Sustainability director Marian Garfield said "We are delighted to have been awarded the 'excellent' level of certification by the Building Research Establishment (BRE), which demonstrates our commitment to sustainability and supporting our customers in our shared net zero ambitions."

India: JSW Cement has appointed Finland-based Coolbrook to install its RotoDynamic Heater electric kiln technology at the Vijayagar steel works and slag and cement grinding plant in Karnataka. Press Trust of India News has reported that the partners expect the technology to reduce the CO₂ emissions of the plant’s slag cement.

Read about the applications for the RotoDynamic Heater in cement production in this Global Cement interview with Coolbrook CEO Joonas Rauramo.

India: Adani Group says that it will power 60% of its cement production using renewable energy by 2028. In a post on X, the group noted that its Adani Cement business uses fly ash or slag in cement production at 90% of its plants.

UK: The World Cement Association (WCA) has welcomed the introduction of the revised BS 8500 standard, which allows for a wider range of Portland limestone cement (PLC) and ground granulated blast furnace slag (GGBFS) combinations in concrete. WCA chief executive officer Ian Riley, however, described the revision as ‘not breaking new ground but catching up.’ He called on the UK and other jurisdictions to begin enacting performance-based standards.

Riley said “It is good to see BSI making this change to concrete standards, however, this is still a very modest step forward. Firstly, ground limestone has been used successfully as a cement component in many markets for decades. Secondly, in order to produce concrete with the lowest embodied carbon and the highest circularity, we need to move away from standards that require particular recipes.”

EU/UK: EUROSLAG says that the use of ground granulated blast furnace slag (GGBFS) in cement production in the EU and UK between 2000 and 2022 has generated a cumulative reduction in CO₂ emissions of 408Mt. GGBFS replaced 716Mt-worth of raw materials over the period.

EUROSLAG Chair Thomas Reiche said "Resource conservation through secondary raw materials, especially in the construction sector, and lower emissions of climate-damaging CO₂, are of outstanding ecological and economic importance. The use of ferrous slags makes an important contribution to this. EUROSLAG is working multilaterally to master the enormous challenges in the coming years, above all the transformation of the steel industry, through research and adjustments to national and European regulations.”

Heidelberg Materials North America held an official opening ceremony this week for its upgraded slag cement plant and terminal at Cape Canaveral in Florida. The US$24m project added a new roller press to the unit to increase its production capacity. In a statement Chris Ward, the president and chief executive officer of the company, said that it had made the investment to meet sustainability and resilient construction goals. Industrial Accessories Company (IAC) said in mid-2021 that it had been named as the engineering, procurement, and construction (EPC) contractor for the project. It planned to install a hydraulic roller press supplied by FLSmidth. IAC also said it was providing instrumentation equipment, hoppers, bins, belt conveyors, bucket elevators and dust collectors amongst other kit and services.

Other recent US slag cement-related news stories have concerned terminals. In late August 2022 Royal White Cement said it had leased a site on the Houston Ship Channel in Houston, Texas to handle and store approximately 100,000t of multiple cementitous products such as slag, ordinary Portland cement and white Cement. In May 2022 Titan America announced plans to spend US$37m on an upgrade to its Norfolk terminal in Chesapeake, Virginia. The major improvement was to add a 70,000t storage dome, with enlarged truck and railway capacity, to allow the site to import and distribute raw materials such as fly ash, slag and aggregates. Completion on this one was scheduled for some point in 2023. Titan added that the project was similar to the addition of a 70,000t dome under construction at the time at Titan's import terminal in Tampa, Florida.

The United States Geological Survey (USGS) estimates that domestic sales of iron and steel (ferrous) slags in the US amounted to 15Mt in 2022. Sales were around 20Mt in the 2000s but this fell to current levels in the 2010s as blast furnaces closed. In 2022 the USGS noted that, “domestic ground granulated blast furnace slag (GGBFS) remained in limited supply because granulation cooling was known to be available at only two active US blast furnaces while, elsewhere, only one domestic plant produced pelletised slag in limited supply.” It added that the grinding of granulated blast furnace slag was only being carried out domestically by cement companies. Imports of slag were 2Mt in 2022. This is a decline from a peak of 2.6Mt in 2018 but higher than the period 2000 – 2015. The price of slag, meanwhile, hit a high of US$53/t in 2022. This is the highest price recorded by the USGS since at least 2000. It is double that of 2017.

Charles Zeynel of ZAG International noted in the June 2023 issue of Global Cement Magazine that cement producers in Florida, California, Texas, Georgia and the Carolinas are far from steel mills, so they import granulated blast furnace slag (GBFS) and other secondary cementitious materials (SCM). This certainly fits with Heidelberg Materials’ plan to upgrade its slag cement plant and terminal at Cape Canaveral. Also on the US market, Zeynel added that due to rising global demand for SCMs more of the available share of GBFS was being purchased by ‘richer’ markets such as Europe, North America and Australia. He continued that GBFS and GGBFS producers had also started increasing the price of their wares internationally. This too is apparent in the prices published by the USGS.

One final story with links to slag to note this week concerns the launch of the Alliance for Low-Carbon Cement & Concrete (ALCC) in Europe. The group brings together companies producing products or services intended to decarbonise the cement and concrete sectors. Two of the members – Ecocem and Hoffman Green Cement Technologies – are Europe-based slag cement producers. Two other members – Fortera and TerraCO₂ – are companies based in North America that are marketing and selling low-carbon SCMs.

Various start-up companies have been emerging on a regular basis in both North America and Europe with the aim of decarbonising cement and concrete in various different ways. The formation of the ALCC can be seen as part of this trend as the more successful non-traditional cement-concrete-aggregate companies establish themselves. One point that cement producers in North America are likely to be well aware of is that concrete is becoming less linked to clinker as the cost of carbon mounts and the clinker factor of cement lowers. Slag supplies may be finite but Heidelberg Materials North America’s latest investment in Florida is further acceptance that one doesn’t just need clinker to make concrete.

Read Charles Zeynel’s interview on SCM Trends in 2023 in the June 2023 issue of Global Cement Magazine

The 15th Global Slag Conference, Exhibition & Awards take place on 6 - 7 June 2023 in Düsseldorf, Germany

France: Hoffmann Green Cement Technologies has commissioned its H2 plant, a 1000t/day clinker-free cement plant, adjacent to its existing H1 clinker-free cement plant in Bournezeau, Pays de la Loire. L'Usine Nouvelle News has reported that the new plant took 24 months to build and cost Euro22m. The main part of the plant consists of a 70m tower, where activated clay, ground granulated blast furnace slag (GGBFS) and gypsum are mixed to produce the cement. It is installed with solar panels capable of supplying 50% of its energy consumption. The producer says that its clinker-free cement has over 90% lower CO₂ emissions than cement produced with ordinary Portland cement (OPC). It aims to sell 24,000t of the product throughout 2023.