Displaying items by tag: Calcined Clay

US: Vicat subsidiary National Cement Company of California has signed a cooperative agreement with the US Department of Energy (DOE) Office of Clean Energy Demonstrations to develop the Lebec Net Zero (LNZ) project at its Lebec cement plant in California.

The agreement commits up to US$500m, covering up to 50% of the Phase one cost. The project includes constructing a CO₂ sequestration facility with a 0.95Mt/yr capacity, enabling the plant to capture ‘almost all’ of the plant’s emissions. It will also increase alternative fuel use from locally sourced biomass and reduce the plant’s clinker factor by producing calcined clay-based cement. The plant will reportedly produce carbon-neutral cement.

The first step will be to conduct a preliminary engineering study and establish a community advisory body in charge of relations with local communities. Phase one will run through the first quarter of 2026.

Portugal: Cimpor recently celebrated the 50^th anniversary of its Souselas plant, which has been operational since November 1974. The plant was initially launched with a production capacity of 500,000t/yr of clinker, but has since adapted to meet market demand.

Throughout its five decades of operation, the Souselas plant has produced over 69Mt of clinker and processed approximately 667,000t of alternative fuels. Current projects include the rehabilitation of Line 2 for producing calcined clays, installing photovoltaic plants and focusing on co-processing and heat recovery initiatives, with the aim to achieve carbon neutrality by 2050. The anniversary event showcased recent projects, such as the installation of a 1MW photovoltaic plant and the planned introduction of a 10MW plant by 2025. Additionally, a 7.4MW waste heat recovery system will commence operation in February 2025 and a 10MW hydrogen plant is scheduled for 2026.

Germany: Aumund and Holcim have demonstrated an electric linear calcination conveyor (eLCC) at Aumund’s headquarters in Rheinberg, Germany. Initial tests of the eLCC have reportedly demonstrated efficient thermal activation of clay through a combination of radiant heat and material circulation. In 2020, Aumund Fördertechnik teamed up with Holcim for a project focused on the electrical calcination of clay using an Aumund pan conveyor.

The company stated that the eLCC system is fully enclosed and insulated, minimising energy requirements and heat loss, with its compact design allowing for expansion of production capacities. It can operate with electrical heating elements powered by 100% renewable energy sources like wind or solar. The first industrial plant utilising this technology will be constructed in 2025.

Burkina Faso: AVIC International Beijing, in collaboration with Humboldt Wedag GmbH (KHD), has won an engineering, procurement and construction (EPC) contract from Ciments de l'Afrique (CIMAF) to build a 900t/day clay calcination plant. This plant aims to integrate with CIMAF's existing clinker grinding line to produce calcined clay cement, potentially reducing CO₂ emissions by up to 30%, according to the company. KHD will be responsible for designing and equipping the plant with clay calcination technology, while AVIC, as the EPC contractor and KHD's parent company, manages the overall project execution.

KHD's system features a two-stage preheater and flash calciner with a pre-combustor, offering adaptability for the future installation of KHD’s Pyrorotor technology to maximise secondary fuel usage. The technology also includes a colour stabilisation process to maintain consistent supply of grey or black calcined clay. The project is scheduled for completion by mid-2026.

CIMAF Group Vice-President, Malik Sefrioui, said "This project is a major piece of our group decarbonisation roadmap, fully financed by IFC under a green loan form. Two other similar projects are being studied and will be launched very soon. The choice of AVIC/KHD is based on their long track record in cement pyro-processing projects. We are sure that this inaugural partnership will deliver significant added value for both parties."

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.

Czech Republic: Holcim Česko, owner of the Čížkovice cement plant, will construct a new calcined clay processing line with an investment of US$44m, marking the largest investment in its history. The project, beginning in January 2025 and aiming for completion by the end of 2026, aims to reduce energy use and end reliance on fossil fuels. The Czech Ministry of the Environment has contributed US$14.5m towards the construction.

Holcim Česko CEO Miroslav Kratochvil said "The new calcined clay processing line represents a revolutionary step in the cement industry. Calcined clays will become a key material in our company's new cement products and will have a significantly lower carbon footprint. This innovation will enable the company to make a significant contribution to environmental protection and emission reduction."

France: F Scott, a French group based in Switzerland, is set to construct a new grinding plant in Montoir-de-Bretagne, Loire-Atlantique, by 2027. The €55m investment is expected to create 50 jobs, according to API agency. The plant will import 300,000t/yr of blast furnace slag and a similar amount of clinker by ship, with plans to potentially switch to calcined clay for producing low-carbon cement. F Scott's proposal was approved in mid-late 2023 following a call for expressions of interest by the major maritime port of Nantes-Saint-Nazaire for a bulk products storage and industrial processing unit.

UK: A new study by the Mineral Products Association (MPA), supported by Innovate UK, has found that incorporating reclaimed clays and finely ground brick powder into cement production can reportedly lower the embodied CO₂ by up to 3%. The materials are used as calcined clay in the cement production process. The project aims to offer a viable alternative to fly ash and ground granulated blast-furnace slag, as resources diminish due to the steel industry's decarbonisation efforts.

MPA director Diana Casey said "Using discarded bricks and reclaimed clays will not only lower carbon and reduce the amount of materials sent to landfill but has the potential to create a whole new market if these clays become widely used in the construction industry, helping to retain economic value in the UK, secure jobs and attract investment."

Burkina Faso: The stone laying ceremony took place on Thursday 8 August 2024 at Ciments de l'Afrique’s (CIMAF) new calcined clay production unit and solar power plant at its plant in Ouagadougou, Burkina Faso. The calcined clay unit is valued at US$50m, while the solar power plant cost US$5.5m, reports Burkina 24. Completion is expected by August 2026.

Ibrahim Traore, president of Burkina Faso, said “The accompanying solar unit should make it possible to reduce production costs and we hope that in a few years, this technology will become popular and will make it possible to reduce cement costs.”

Anas Sefrioui, chair and CEO of CIMAF Group, said “The calcined clay that we will produce here in Burkina will serve as an alternative raw material to imported materials, particularly clinker.”

Cameroon: Cimpor has inaugurated its new plant in Kribi, Cameroon. Following investments in Côte d'Ivoire, Cimpor embarked on this greenfield project in February 2020, integrating the ‘world's first’ operational flash calcined clay production line, launched on 29 October 2023.

Cimpor Cameroun now has an output of 1.2Mt/yr of cement and 0.4Mt/yr of calcined clay. Cimpor's calcined clay production technology - ‘deOHclay’ – reportedly saves up to 80% in CO₂ emissions, up to 35% in electricity consumption and up to 40% in thermal energy consumption per tonne. Compared to a plant with a similar capacity, this technology could reduce CO₂ emissions by around 0.2Mt/yr, according to the company. The new plant will reduce the country’s dependence on imports to meet local cement needs.