Displaying items by tag: Slag

India: Jindal Panther Cement (JPC), part of the Jindal Group, has commissioned its first cement grinding unit with a capacity of 1.5Mt/yr at Angul, Odisha. The unit will use about 1Mt/yr of blast furnace slag from Jindal subsidiary Jindal Steel & Power’s (JSPL) nearby integrated steel plant, operating with the industry's lowest clinker factor as part of its decarbonisation strategy. The Angul grinding unit will produce low-carbon Portland slag and composite cement for central and eastern India, repurposing waste from JSPL's operations and aligning with the group's decarbonisation goals. In the future, JPC plans to increase production capacity at both of its facilities, Angul and Raigarh, to 7Mt/yr, with an investment of US$257m.

CEO of JPC, Rohit Vohra, said "The commissioning of our Angul grinding unit marks a significant step in our journey towards a sustainable future. Our low-carbon cement and innovative distribution model position us uniquely to support eastern India's infrastructure growth while contributing to a greener planet."

One unusual thing about coverage of cement in the media is the way that discussions often centre precisely on its absence – that is, on alternatives to cement. These alternatives boast unique chemistries and performance characteristics, but are all produced without Portland cement clinker. They are generally called ‘alternative cements,’ perhaps because ‘cement-free cement’ does not have such a commercially viable ring to it. This contradictory tendency reached a new high in the past week, with developments in alternative cement across Asia, Europe, the Middle East and North America. Together, they hint at a more diverse future for the ‘cement’ industry than the one we know today.

Asia

In Indonesia, Suvo Strategic Minerals has concluded tests with Makassar State University of a novel nickel-slag-based cement. Huadi Nickel-Alloy Indonesia supplied raw materials, and tests showed a seven-day compressive strength of 37.5MPa. Suvo Strategic Minerals says that a partnership with Huadi Nickel-Alloy Indonesia for commercial production is a likely next step.

Europe

Cement producer Mannok and minerals company Boliden partnered with the South Eastern Applied Materials (SEAM) research centre in Ireland to launch a project to develop supplementary cementitious materials (SCMs) from shale on 7 October 2024. The project will additionally investigate CO₂-curing of cement paste backfill for use in mines. Irish state-owned global commerce agency Enterprise Ireland has contributed €700,000 in funding.

UK-based SCM developer Karbonite expects to launch trial production of its olivine-based SCM with a concrete company in 2025. The start-up launched Karbonite Group Holding BV, with offices in the Netherlands, to facilitate this new phase. Karbonite’s SCM is activated at 750 – 850°C and sequesters CO₂ in the activation process, resulting in over 56% lower CO₂ emissions than ordinary Portland cement (OPC). Managing director Rajeev Sood told Global Cement that talks are already underway for subsequent expansions into the UAE and India.

Back in the UK, contractor John Sisk & Son has received €597,000 from national innovation agency Innovate UK. John Sisk & Son is testing fellow Ireland-based company Ecocem’s <25% clinker cement technology in concrete for use in its on-going construction of the Wembley Park mixed development in London.

At the same time, Innovate UK granted a further €3.23m to other companies for concrete decarbonisation. Recipients included a calcined clay being developed by Cemcor, an SCM being developed from electric arc furnace byproducts by Cocoon, a geopolymer cement technology being developed by EFC Green Concrete Technology UK and an initiative to develop alternative cement from recycled concrete fines at the Materials Processing Institute in Middlesbrough. Also included was the Skanska Costain Strabag joint venture, which is working on the London stretch of the upcoming HS2 railway. The joint venture, along with partners including cement producer Tarmac and construction chemicals company Sika UK, will test low-kaolinite London clay as a raw material with which to produce calcined clay as a cement substitute in concrete structures in HS2’s rail tunnels.

Middle East

Talks are underway between UK-based calcined clay producer Next Generation SCM and City Cement subsidiary Nizak Mining Company over the possible launch of a joint venture in Riyadh, Saudi Arabia. The joint venture would build a 350,000t/yr reduced-CO₂ concrete plant, which would use alternative cement based on Next Generation SCM’s calcined clay.

North America

Texas-based SCM developer Solidia Technologies recently patented its carbonatable calcium silicate-based alternative cement, which sequesters CO₂ as it cures.

Meanwhile, C-Crete Technologies made its first commercial pour of its granite-based cement-free concrete in New York, US. C-Crete Technologies says that the product offers cost and performance parity with conventional cement, with net zero CO₂ emissions. Its raw material is globally more abundant than the limestone used as a raw material for clinker. Other abundantly available feedstocks successfully deployed within C-Crete Technologies’ repertoire include basalt and zeolite.

Across New York State, in Binghamton, KLAW Industries has succeeded in replacing 20% of concrete’s cement content with its powdered glass-based SCM, Pantheon. KLAW Industries has delivered samples to local municipalities and the New York State Department of Transportation. Its success expands the discussion of possible circular cement ingredients from the industrial sphere into post-consumer resources.

In Calgary, Canada, a novel SCM has drawn attention from one of the major cement incumbents: Germany-based Heidelberg Materials. It invested in local construction and demolition materials (CDM)-based SCM developer EnviCore on 9 October 2024. The companies plan to build a pilot plant at an existing Heidelberg Materials CDM recycling centre.

Conclusion

Alternative cement developers are still finding the words to talk about their products. They may be more than ‘supplementary’ up to the point of entirely supplanting 100% of clinker. Product webpages offer ‘hydraulic binder,’ ‘pozzolan’ and even ‘cement.’ As alternative ‘cements’ are developed, they build on the work of pioneers like Joseph Aspdin and Louis Vicat. Start-ups and their backers are now reaching commercial offerings, on a similar-but-different footing to cement itself. None of these novel materials positions itself as the sole, last-minute ‘super sub’ in the construction sector’s confrontation with climate change. Rather, they are a package of solutions which can combine into a net zero-emissions heavy building materials offering, hopefully before 2050.

Related to this is the need for ‘technology neutral’ standards, as championed this week by the Alliance for Low-Carbon Cement and Concrete (ALCCC), along with 23 other European industry associations, civil society organisations and think tanks. The term may sound new, but the concept is critical to the eventual uptake of alternative cements: standards, the ALCCC says, should be purely performance-based. They ought not attempt to define what technology, for example cement clinker, makes a suitable building material. According to the ALCCC, Europe’s building materials standards are not technology neutral, but instead ‘gatekeep’ market access, to the benefit of conventional cement and the exclusion of ‘proven and scalable low-carbon products.’

At the same time, cement itself is changing. Market research from USD Analytics showed an anticipated 5% composite annual growth rate in blended cement sales between 2024 and 2032, more than doubling throughout the period from US$253bn to US$369bn. If you can’t beat it, blend with it!

For a further discussion of alternative cement and binders in Europe, see Global Cement’s interview with ALCCC co-ordinator Joren Verschaeve in the forthcoming November issue of Global Cement Magazine on 17 October 2024.

Indonesia: Suvo Strategic Minerals has reported successful laboratory tests in collaboration with Makassar State University (UNM) in Indonesia, transforming nickel slag into a ‘high-strength, low-cost and low-carbon’ cement, according to The Sydney Morning Herald. The trials used slag from PT Huadi Nickel-Alloy Indonesia's operations in South Sulawesi, achieving a compressive strength of 37.5MPa after seven days. The company is now looking to conduct further testing and will provide the results to PT Huadi, with the aim of forming a partnership for the commercialisation of low-carbon cement using nickel slag.

Aaron Bank, executive chair of Suvo Strategic Minerals, said “We are excited to have commenced this workstream in Indonesia testing the byproduct of one of the country’s largest mining companies, with our ultimate goal being to manufacture an environmentally-friendly and low-carbon alternative to Portland cement. Achieving up to 37.5MPa after only seven days is an outstanding first round trial result for the company and could provide an entry into a large industry.”

UK: UK-based startup Cocoon has raised €4.9m in pre-seed funding to develop technology that repurposes byproducts from electrified steel furnaces into a ‘near-identical replacement’ for blast furnace slag, according to the company. The modular technology integrates into existing steel-making processes without disrupting operations or requiring high capital expenditure, reports UK Tech News. Cocoon targets a 50% replacement of cement in concrete, aiming to reduce emissions for producers. Initial tests are underway at a steel plant in northern England, followed by another in the US.

Cocoon CEO Eliot Brooks said "We’re turning a byproduct with little use into a valuable product that the market badly needs and can be easily integrated into existing supply chains. By repairing a broken link in the circular economy, Cocoon provides steel makers with a new revenue stream while meeting the low-carbon material needs of the concrete industry. For every 1t of Cocoon’s slag-based cementitious material used, 1t of CO₂ can be avoided."

Brooks hopes Cocoon's climate technology will be integrated into a pilot plant by late 2025.

Australia: The new Geelong grinding plant, situated near Lascelles Wharf in Victoria, has commenced operations. It has the capacity to grind 1.3Mt/yr of granulated blast furnace slag and clinker. It will utilise slag to reduce landfill waste and substitute cement in concrete products. According to Boral’s post on LinkedIn, the plant will provide direct and indirect job opportunities to help boost the Geelong economy.

UK: A steel and cement co-recycling process developed at the University of Cambridge has received US$2.9m in seed funding. Cambridge Electric Cement is utilising slag produced during the steelmaking process, which uses electric arc furnaces instead of blast furnaces, as clinker for cement. The researchers are conducting a US$8.4m trial called Cement 2 Zero to test the production process, aiming to produce 110t of recycled cement during the two-year program.

US: Heidelberg Materials has successfully converted its cement plant in Speed, Indiana, into a slag grinding facility. The facility ceased Portland cement production in 2023 following the opening of a new plant in Mitchell, Indiana, and now produces slag cement using domestically sourced slag granules. The Speed site has a grinding capacity of over 400,000t/yr and also functions as a distribution hub for the Mitchell plant's cement and other products.

Philippines: A new 7-hectare port and industrial complex, valued at over US$51m, is under construction in Lemery, Batangas. The complex includes the Sinisian Lemery Batangas port and industrial park, Lemery cement silo tank and Lemery oil terminal, with each component costing around US$17m.

The port will support Panamax-sized vessels with a draft depth of 15m, while the cement silo will hold 60,000t of bulk cement and slag. The project is expected to generate at least 200 jobs and help meet the country's fuel security needs amidst ongoing global supply chain disruptions.

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."

China: A new study from Hong Kong Polytechnic University showcases sustainable cement production methods, focusing on low-clinker cements and alternative solutions for incinerator fly ash (IFA). The research demonstrates that using carbonated-washed IFA mixed with slag, coal fly ash, or metakaolin can replace 60% of Portland cement, forming ternary blended cement. This approach reportedly reduces the carbon footprint of cement production.

The study found that slag was the most effective, improving pore structure and increasing ettringite and hemicarboaluminate formation with a blend of 40% slag and 20% IFA. It achieved 90% of the compressive strength of pure Portland cement after 90 days.

The researchers said "This study demonstrated the promising potential of the blended cements to simultaneously divert IFA from landfills and reduce the clinker content of cement."