Displaying items by tag: Steel slag

US: Research by the United States Geological Survey (USGS) estimates that local sales of iron and steel (ferrous) slags were 15Mt in 2022 with a value of around US$795m. This is a slight decrease from the 15.7Mt reported in 2021. 49% of the volume sold in 2022 was blast furnace slag and this accounted for the majority of the total value of the slag. Steel slag produced from basic oxygen and electric arc furnaces accounted for the remainder of sales. Around 2Mt of slag was imported for consumption.

The USGS said that slag was processed by 25 companies servicing active iron and steel facilities or reprocessing old slag piles at about 123 processing plants in 33 states, including facilities that import and grind unground slag to sell as ground granulated blast furnace slag (GGBFS). It added that domestic GGBFS remained in limited supply in 2022 because granulation cooling was available at only two active US-based blast furnaces and only one local plant produced pelletised slag in limited supply. It noted that granulated blast furnace slag was only ground domestically by cement companies.

India: The Border Roads Organisation (BRO) has used steel slag to construct a 1km section of National Highway 713 that connects Arunachal Pradesh's Kurung Kumey district to the Chinese border. The slag material was donated by Tata Steel and transported from Jamshedpur to Arunachal Pradesh by Indian Railways free of charge, according to the Press Trust of India. The project was an initiative of BRO Director General Lt Gen Rajeev Chaudhry to introduce sustainable new technologies with the help of Central Road Research Institute-Council for Scientific & Industrial Research (CRRI-CSIR) and Tata Steel.

UK: Teesside University is working with a number of partners, including Material Evolution, on developing a new type of concrete using steel slag. The ‘Mevocrete’ project has a total budget of Euro8.6m and it received around Euro3.5m funding from the Innovate UK scheme. It intends to build a full scale on-site unit for cement production using waste steel slag at the Teesworks industrial zone. Researchers from the university’s School of Computing, Engineering & Digital Technologies will analyse the steel slag and its chemical composition and measure how efficient it is at sequestering carbon. The projects aims to manufacture a concrete that emits up to 85% less CO₂ compared to a traditional concrete made from Ordinary Portland Cement (OPC).

Material Evolution is the lead industrial partner on the project. Other partners include Celsa Manufacturing UK, LKAB Minerals, Nanomox, Enursan, Retaining UK, Geocast, Playfair Capital and ZTL Contracting.

UK: SteelPhalt has launched a carbon-negative asphalt product called SteelSurf ECO+. The asphalt use 95% recycled steel slag with a lignin binder made from trees. The kraft lignin is supplied by GautamZenUK in collaboration with Stora Enso. It is used as an alternative to bitumen, which previous SteelPhalt asphalt products used instead.

"In our journey to become the world's most sustainable asphalt supplier, this is a huge step forward,” said Julian Smith, SteelPhalt Strategic Growth Director. “This product is an example of what our team’s collective passion for innovation and sustainability can deliver, while making the world a greener place.”

Steelphalt is a part of the Harsco Environmental division of US-based Harsco.

India: The first steel slag road in India has been built in Surat, Gujarat. The 1.2km road is located at Hazira Port, according to the Times of India newspaper. It was constructed by using steel slag aggregate in place of natural aggregate. The higher strength of the material has also allowed for the thickness of the road to be reduced by 30%. Around 100,000t of steel slag was used. The joint project was a collaboration between the Council of Scientific and Industrial Research, the Central Road Research Institute, the Union Ministry of Steel, government think-tank NITI Ayog and ArcelorMtttal-Nippon Steel.

US: The United States Geological Survey (USGS) estimates that the US sold 17Mt of ferrous slags in 2021, a rise of 31% year-on-year from the estimate in 2020. Blast furnace slag represented about 49% of the volume sold and accounted for 87% of the total value ofslag, most of which was granulated. Steel slag produced from oxygen and electric arc furnaces accounted forthe remainder of sales. Slag was processed by 28 companies servicing active iron and steel facilities or reprocessing old slag piles at about 124 processing plants, including some iron and steel plants with more than one slag-processing facility, in 33 States, including facilities that import and grind unground slag to sell as ground granulated blast furnace slag (GGBFS).

A further 2.2Mt was imported, a slight decline from 2020. From 2017 to 2020 the USGS reports that 42% of imported slag came from Japan, 18% from Brazil, 11% from China and 10% from Italy.

The USGS noted that during 2021, domestic 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. Grinding of granulated blast furnace slag was only performed domestically by cement companies. However, following Covid-19 related decrease in availability in 2020, supply of steel slag increased in 2021.

Spain: Sidenor has launched Termoslag, a software for the control of slag transit during liquid steel dumping. It aims to reduce steel’s slag content by 10%, thereby reducing raw materials and energy consumption in the steel production process and increasing slag output for circular economic uses such as cement production. Sidenor said, “We are committed to eco-innovation and the circular economy.”

Australia: Boral Australia has launched Innovo, an asphalt system product that uses steel slag as a raw material amongst other recyclables. Recycled materials that can be used in the mix include steel slag, recycled plastics, tyres, recycled crushed glass, recycled asphalt pavement and printer toner. The product has been used in various projects in Queensland, New South Wales, Victoria, South Australia and Western Australia.

Japan: Taiheiyo Cement, JFE Steel and the Global Institute for Environmental Technology are working together to develop a carbon capture and storage system. The system will use wet alkaline earth metals extracted from steel slag to produce carbonates from exhaust gases at cement and steel plants. The partners are investigating the possibility of using these carbonates, specifically calcium carbonate and magnesium carbonate, as additives in cement production at Taiheiyo Cement’s plants. Taiheiyo Cement president Masafumi Shigehara said, “With the effects of climate change becoming apparent both in Japan and overseas, the importance of global warming counter-measures is increasing.”

Canada/US: Harsco’s Environmental division has invested US$2.3m in Carbicrete, a Canadian technology company developing concrete products made with steel slag for the construction industry. The investment will give Harsco Environmental a Board seat in Carbicrete and has been made in conjunction with a US$1.6m grant from the Government of Canada’s Sustainability Development Technology Canada Foundation and applications to further government grant programs. Harsco’s investment will aid the development of the technology through a demonstration program with support from a commercial concrete block manufacturer as part of a development consortium.

“This investment in innovation is aligned with Harsco’s on-going expansion into environmentally-focused products and services, and we are proud to support the development of this exciting technology,” said Harsco Environmental chief operating officer Russ Mitchell.

Carbicrete is developing a technology that allows the production of concrete without using cement by using steel slag instead. The concrete mix is poured into molds, like conventional concrete, and is then cured using CO₂. During curing, the gas becomes a solid, binding together the slag granules, and giving the concrete its strength. Carbicrete says the process can be implemented in any precast concrete manufacturing plant. It also says that the technology is ‘carbon negative’ because more CO₂ is consumed than emitted during the process.