With the purchase of Companhia Siderúrgica do Pecém (CSP) last year, ArcelorMittal saw an opportunity to turn its waste into value by investing in a project by researchers at the Federal University of Ceará (UFC) that transforms waste ‘blast furnace into a cement that claims to be less polluting, although more expensive than conventional cement.
The purchase of CSP was completed in March 2023 for $2.2 billion and gave ArcelorMittal control of the plant installed in Pecém (CE) which already supplied steel scrap to UFC research.
The plant operates a blast furnace with the capacity to produce 3 million tonnes of steel per year which generates 1.95 million tonnes of waste, enough to produce up to 1.5 million tonnes of low carbon cement, according to ArcelorMittal.
The research plans to produce a concrete that emits up to 75% less carbon than that generated in the production of traditional concrete, as well as being more resistant, according to UFC researchers.
But despite the advantages of the new material, it still faces two challenges: price and applicability.
According to UFC researchers, so-called “green concrete” can be three times more expensive than conventional concrete and its use requires specialized labor.
“We understand that, from an economic point of view, it is not the most economical solution at the moment, but it is a solution that allows us, on a large scale, to reduce this value for society,” said the head of infrastructure and co-products of ArcelorMittal Pecém, Alex Birth. .
“Moreover, it gives us the possibility to look, in parallel, for solutions that could even transform this knowledge acquired by the university into something more economical,” he added.
ArcelorMittal plans to invest 1 million reais in the project in 2025 and to organize, also next year, a roadshow for construction companies and operators in the sector, with the construction of two “eco houses”, using the new cement, in the Pecém plant.
According to Nascimento, the next phase of development is the construction of a pilot factory, although such an installation is not yet planned.
“Our idea is to move away from the laboratory scale and do a pilot project, on a smaller scale,” he said. In this sense the company intends to evaluate partnerships through its roadshow.
MORE SUSTAINABLE CEMENT?
Low-carbon concrete, also known as “green concrete” or “eco-concrete”, is a geopolymer formed from industrial waste, such as steel slag and fly ash, that comes from the combustion of fuel in coal-fired thermal power plants , mixed with caustic soda. Unlike (traditional) Portland cement, it does not require heating up to 1,500 degrees, avoiding the release of polluting gases into the atmosphere in this part of the process.
Although there are positive environmental aspects, according to researchers and industry representatives the applicability of the material still represents a challenge, as caustic soda is toxic and requires special care when handling.
“It involves a different set of precautions than conventional concrete,” said UFC researcher Heloína Nogueira, who developed the composition. According to her, despite the use of caustic soda, the final formula still has lower CO2 emissions than conventional cement. The formula received a patent from the National Industrial Property Institute (Inpi) in March this year.
According to Marcelo Pecchio, technology manager of the Brazilian laboratory of the Portland Cement Association (ABCP), the geopolymer could end up being used only locally and serving a narrow market.
“You might even be able to develop it locally. For example, in Pecém, nearby, you might actually be able to develop a geopolymer plant… But it is far from being a material that is available, for example, throughout Brazil “
Another obstacle is the price. According to Nogueira, low-carbon cement can cost three to five times the production value of 1 kilo of ordinary cement, or about 0.70 reais.
“(But) with the paradigm shift of companies looking for sustainability, looking for carbon emission reductions, there could be an offset,” he said. It also mentions “green” financing lines, emissions and large-scale production.
“Some banks have created financing lines for businesses and construction companies where interest rates to finance sustainable works are lower.”
A more immediate alternative is to prioritize the use of CP2 and CP3 cements, Pecchio explained, whose composition can contain up to 70% steel slag, resulting in lower carbon emissions than other types of cement. The construction company MRV says it already uses these solutions which, according to the executive director of sustainability of the MRV&Co group, Raphael Lafetá, have helped the company reduce polluting emissions related to the use of cement by up to 35% in 2023.
HIGHER PRICES
According to Luiz França, president of Abrainc, an association representing around 80 developers in the country, the material can represent an alternative for the development of more sustainable projects in the future, despite the higher prices.
“Depending on the company’s strategy and the specifics of the projects, it could become more attractive than other types of cement,” França explained in a statement.
“Another important point is that the reduction of greenhouse gas emissions guaranteed by the use of green concrete brings additional benefits such as brand appreciation. These factors contribute to the positioning of the company and add value to the company.”
ArcelorMittal’s investments in research aimed at reusing waste and launching co-products in Pecém amount to around 17 million reais this year, according to Nascimento, and include niches ranging from mortar and concrete, to fertilizers and “prefabs”.
Although little known, geopolymers, made from industrial waste products combined with an alkaline substance, are nothing new. The researcher recalls that, in Australia, a University of Queensland project inaugurated in 2013 a project created with 33 prefabricated panels in geopolymer-based concrete, without the use of Portland cement.
Source: Terra
Rose James is a Gossipify movie and series reviewer known for her in-depth analysis and unique perspective on the latest releases. With a background in film studies, she provides engaging and informative reviews, and keeps readers up to date with industry trends and emerging talents.
