Displaying items by tag: supplementary cementitious materials

UK: Riku Kytömäki, the chief executive officer of Betolar, has called for a global performance-based standard to replace the current building requirements that restrict the use of new low-carbon materials to replace cement in concrete production. He made the comments at the London Concrete Expo. Kytömäki argued that current standards state that concrete manufacturers must use a certain percentage of cement to strengthen the finished product. Betolar’s product Geoprime is an additive designed for use in cement-free concrete production with ash and ground granulated blast furnace slag (GGBFS). However, “ageing” standards rule out the use of these kinds of products such as this despite their sustainability advantages.

Kytömäki said “It is time for global concrete industry to step up their sustainability efforts. New material innovation is available. It is cost-effective and helps to meet stricter durability requirements. However, the current regulations across the markets are restricting the use of circular materials allowed in concrete buildings.” He added that his company’s product Geoprime, “does not require large investments, but there is regulation to be developed quickly so that new solutions and materials can be used."

Betolar says it has analysed over 200 side-streams other than slag and fly ash, providing flexibility to process locally available side-streams. It added that there are also significant CO₂ savings to be found in logistics when manufacturing processes take place near the source of the industrial side-streams.

Canada: The Cement Association of Canada (CAC), with its members and partners in the concrete sector, has released Concrete Zero, an action plan to help the local cement and concrete sector reach net-zero CO₂ emissions by 2050. The five priority areas it is focusing on include: eliminating the use of coal and petroleum coke as fuel sources for clinker production; reducing the volume of clinker used to produce cement; increasing the use of supplementary cementitious materials; working towards building carbon capture, utilisation and storage capacity; and advocating for performance-based codes, standards and specifications, procurement policies and increased material efficiency in construction. Targets include reaching a 100% fuel mix from non-fossil-based sources by 2050. The latest plant follows the goal of achieving a 40% emissions reduction by 2030 as part of its Roadmap to Net-Zero Carbon Concrete by 2050.

Adam Auer, the president and chief executive officer of CAC, said “Our net-zero action plan is ambitious and cannot be achieved by industry action alone. Working with government, industry, and partners in the design, architecture, and construction industry will be essential for success. Canada’s cement and concrete industry are committed to doing our part to help Canada build a better, cleaner future. Working together, we can deliver Concrete Zero.”

US: ASTM International’s concrete and concrete aggregates committee (C09) is developing a proposed standard specification for a broad range of supplementary cementitious materials (SCM). Larry Sutter, an ASTM International member and the principal engineer at Sutter Engineering, commented that this performance specification (WK70466) will ease the adoption of new materials used for SCMs as established sources become less available.

Sutter said “For a variety of reasons, historic sources of SCMs, like coal fly ash from electric power generation, are in short supply and new materials are emerging.” He added, “These new materials do not fall under existing specifications, leading to the need for new specifications. Rather than writing a new specification for every emerging material, we are writing a performance specification that can be used to cover the full range of them.”

Sutter noted that concrete made with SCMs can be less costly, more durable and more sustainable than ordinary Portland cement. New specifications will allow these new materials into more construction projects. This effort relates to the United Nations Sustainable Development Goal #7 on clean and affordable energy.

Heidelberg Materials announced a US acquisition at the same time as the ongoing IEEE/IAS-PCA Cement Conference in Dallas, Texas this week. It has entered into a purchase agreement to acquire The SEFA Group, a fly ash recycling company based in Lexington, South Carolina. Its operations include five beneficiation plants, five utility partners, 20 locations and over 500 employees. It supplies fly ash to over 800 ready-mixed concrete plants in 13 states. It processes around 1Mt/yr of ash from storage ponds using its proprietary thermal beneficiation process. No value for the acquisition was disclosed.

The proposition for a heavy building materials manufacturer of securing a supply of fly ash is an attractive one. Fly ash can improve the performance of concrete, reduce its cost by lowering the amount of ordinary Portland cement (OPC) required and decrease the associated carbon footprint. It can also be use to make blended cement products. Heidelberg Materials and its US-subsidiary Lehigh Hanson could have various options here including using this new supply of fly ash internally, selling it on to other companies or licensing the beneficiation technology. Heidelberg Materials’ global sustainability report in 2021 reported that just under 9% of its cement-type portfolio comprised pozzolana or fly ash cements.

Graph 1: Coal combustion product production and use, 1991 – 2021. Source: ACAA.

Data from the American Coal Ash Association (ACAA) shows in Graph 1 that coal combustion products (CCP) production have declined in the last decade as the proportion used has steadily risen. In its annual production and use survey, the ACAA revealed that the use of harvested ash continued to grow in 2021 and that it constituted around 10% of the volume of ash recycled from current power plant operation. Thomas H Adams, the executive director of the ACAA, said “The rapidly increasing utilisation of harvested CCP shows that beneficial use markets are adapting to the decline in coal-fuelled electricity generation in the US. New logistics and technology strategies are being deployed to ensure these valuable resources remain available for safe and productive use.” Separately, the ACAA reported that coal-fuelled power stations represented about 50% of the country’s electricity demand in the mid-2010s compared to 20 – 25% in 2021 despite base-load remaining the same. It forecast that fly ash production was likely to remain fairly constant to around 2040 but that harvesting would help to cut the gap between supply and demand in some regional markets. It said that over 2Bnt of coal ash was in disposal. However, no indication of how recoverable this was given although it did note the higher cost of beneficiation. Work on updating specifications was ongoing to suit current circumstances.

As with the slag market, this presents a dilemma for cement and concrete producers that want to become more sustainable. They want to use more by-products from other carbon-intensive heavy industries – such as coal-fired power stations and steel plants – but these industries themselves are also trying to become more sustainable and are producing less secondary cementitious materials. Heidelberg Materials’ interest in a fly ash beneficiation company makes sense because it secures a bigger portion of a dwindling resource from the direct operations and opens up the possibility of selling the beneficiation technology to others. It is also worth mentioning that other fly ash thermal beneficiation processes are available. For example, Charah Solutions installed its MP618 technology at its Sulphur terminal in Louisiana in early 2019.

The general fly ash market in the US looks set to track the level of coal-fired power generation for the foreseeable future. Yet the proportion of CCPs being used continues to rise. In this context focusing on harvesting may be starting to make more financial sense. Charah Solutions’s new unit in 2019 and SEFA Group’s new units in 2020 and 2021 seem to support this view. Heidelberg Materials’ acquisition of SEFA Group may be further confirmation of this.

US: Germany-based Heidelberg Materials has entered into a definitive purchase agreement to acquire The SEFA Group Inc., the largest fly ash recycling company in the US. Based in Lexington, South Carolina, the operations of The SEFA Group include five business units, five utility partners, 20 locations and more than 500 employees. The group currently supplies quality fly ash to more than 800 concrete plants in 13 states.

Heidelberg Materials said that the reuse of fly ash from energy generation in alternative products such as composite cements enhances its circularity efforts within its value chain by reducing the CO₂ emissions of its cement and concrete. The transaction is anticipated to close in June 2023.

“Fostering circularity by increasing the use of by-products and recycled materials from other industrial sectors is an essential part of our strategy,” said Dr Dominik von Achten, Chairman of the Managing Board at Heidelberg Materials. “Our focus is on rapidly and significantly reducing our CO₂ emissions and The SEFA Group will make an outstanding contribution in this regard to our US business.”

UK: The UK government has committed to investments worth Euro22.8bn in early deployments of carbon capture technology. It will announce a shortlist of new projects for deployment later in March 2022.

The government said "This unprecedented level of funding for the sector will unlock private investment and job creation across the UK, particularly on the east coast and in the North West of England and North Wales. It will also kick-start the delivery of subsequent phases of this new sustainable industry in the UK."

Ireland-based Ecocem responded to the budget with a call for funding for more short-term areas besides carbon capture. It said these will be essential in order for the UK cement and concrete industry to reach its 45% decarbonisation target by 2030. The slag-based cement products company called for funding for low-clinker technologies which have already been developed and can be rolled out at scale before 2030, until carbon capture becomes a 'scalable, viable option.'

Canada: Progressive Planet has secured a contract to supply its PozGlass recycled glass-based supplementary cementitious material (SCM) to Lafarge Canada. The cement producer says that it will test the commercial viability of all PozGlass produced at Progressive Planet's Kamloops pilot plant in British Columbia, once the plant commences PozGlass production in 2024.

UK: Cambridge Electric Cement (CEC) has launched the two-year trial of its Cement 2 Zero project, aimed at scaling up production of its net zero-CO₂, demolition waste-based alternative cement. It aims to produce 20t of the material for use in a low-impact construction project. CEC’s method, developed at the University of Cambridge, is based on the conversion of demolition waste into a slag-forming material within a steel furnace.

Developer Julian Allwood said “By combining steel and cement recycling in a single process powered by renewable electricity, we could supplement the global supply of the basic construction materials to support the infrastructure of a zero emissions world and to enable economic development where it is most needed.”

Australia: Germany-based Christian Pfeiffer has received an order for a grinding circuit comprising a 16.3m-long ball mill and a QDK T 250-Z type separator from Hallett Construction Materials. The circuit will have a capacity of 84t/hr, according to the supplier. Hallett Construction Materials plans to use the equipment at its upcoming Port Augusta slag cement grinding plant. The plant is scheduled for commissioning in January 2024.

Hallett Construction Materials chief executive officer Kane Salisbury said, “For us, the sustainability of the plant is the highest priority. That’s why we manufacture cement containing 100% slag.” Salisbury added “The Christian Pfeiffer process experts convinced us that the ball mill, in combination with a high efficiency separator, is the best system to serve our requirements.”

Peru: Unacem Perú plans to 'significantly increase' its cement production capacity 'in the medium-term future.' Prior to that, the producer will invest US$130m in capital expenditure during 2023, double what it invested in 2022. The investments will go towards slightly expanding the producer's capacity from 8.3Mt/yr and increasing alternative raw materials use in its cement production, including pozzolan and ground granulated blast furnace slag (GGBFS). Additionally, it will open its new Manchay limestone quarry in Pachacámac in early 2023.

Unacem said that it increased its cement sales 'unexpectedly' during 2022. It operated at 85 - 90% capacity utilisation, and continued to export clinker.