A trio of slag cement stories have been in the sector news this week with reports from Australia, France and Sri Lanka. Of note from the first two reports is a focus on supplies of slag.

The first concerns Hallett Group’s US$80m supplementary cementitious materials (SCM) project in South Australia. This will see the company process slag and fly ash sourced from sites in the region to manufacture blended cement products and standalone SCMs. These will be principally milled, blended and distributed from a site at Port Augusta. However, an additional distribution site at Port Adelaide is also planned that can both import and export the company’s products in a bid to cut down on supply chain risk, particular for its mining customers. The company says it will replace up to 1.15Mt/yr of cement when fully operational, although initial production looks set to be about a third of this based on local media reports. Commissioning of the Port Adelaide distribution hub is scheduled for May 2023, following by the Whyalla Granulator in January 2024 and the Port Augusta processing plant in June 2024. Pointedly, Hallett Group is explicit about where is plans to source its SCMs from: Nyrstar Port Pirie and, potentially, Liberty GFG.

The second slag-themed story hails from France, where Hoffmann Green Cement has acquired ABC Broyage, which operates a slag grinding plant in North Dordogne. Like the project in Australia above, Hoffmann Green is focused on its supply chain. With this acquisition it will be able to grind its own blast furnace slag instead of buying it. Raw blast furnace slag will be imported via the port of La Rochelle where the company has storage silos. It will then be ground at the former ABC Broyage site and sent on to Hoffmann Green’s H1 and H2 production sites, located at Bournezeau in the Vendée region. Finally it will use it to manufacture its H-UKR and H-IONA cement products. There is no mention of how much the acquisition is costing Hoffman Green. Instead the emphasis, according to company founders Julien Blanchard and David Hoffmann, is very much to, “strengthen our control over our supply and secure our margins in the current highly inflationary context.”

Finally, the week’s third slag-themed cement story is from Sri Lanka, where local media reports that Insee Cement has started producing Portland Composite Cement, using SCMs such as slag, at its Ruhunu grinding plant. This story follows the trend of cement producers around the world switching to greater usage of blended cements, often for sustainability reasons. Unfortunately, political events in Sri Lanka are overshadowing everything else locally, with the president having fled amid social unrest provoked by the ongoing and severe economic crisis. To this end Insee Cement has astutely also donated medical supplies this week to the intensive care unit at the Colombo National Hospital.

These slag stories are important for the cement sector can be demonstrated by a recent update to the Center for International Climate and Environmental Research - Oslo’s (CICERO) research on global CO₂ emissions from cement production. When it published its estimate for 2021 it found that overall emissions were 2.6Bnt in 2021 or just over 7% of the world’s total CO₂ output. What is worse though, is that its data suggests that cement-based emissions have steadily grown year-on-year from 1.2Bnt in 2002. Apart from a dip in 2015 they have kept on rising! This can mostly be attributed to the growth of the Chinese cement industry in the early 2000s suggesting that a tipping point may be reached in the current decade as lowering cement production CO₂ intensity finally kicks in.

Slag and other SCM-based blended cements fit in here as they are one of the ‘easiest’ ways to reduce the clinker factor of cement and concrete and thereby reduce the sector’s CO₂ levels. Hence they keep popping up on the various roadmaps and reports for the cement industry to reach net zero. The flipside of this however is that slag is becoming harder to source as the demand for granulated blast furnace slag increases and less new steel plants get built, especially in North America and Europe. Hence the focus on the supply of slag in the first two news stories above. Blended cements may be the future but getting there will be far from simple.