In this column I have summarised the history of the Universe from the Big Bang some 14.6Bn years ago until the present day, and have also looked at the future of the universe until it just fades away, aeons hence, I thought I would fill in the gap by summarising the whole history of the cement industry - so far.
Mineral-based binders have been used for many thousands of years, with clay and lime (burned limestone) being combined to form a self-hardening material that was used to construct floors, foundations and walls in the Balkans and the Middle East from around 7000 years ago onwards. Gypsum and lime-based plasters and mortars were used by the ancient Egyptians and Greeks. The Romans, from around 2100BCE, found that mixing burned limestone, sand and natural pozzolanic materials from volcanic deposits would make a strong binder that would even harden under-water. Many examples of Roman construction using this early cement are still standing today.
From the dissolution of the Roman Empire to the mid-17th century, the secret of ‘Roman’ cement seems to have been lost, with construction relying on weaker, non-pneumatic (capable of hardening under water) binders. However, during investigations for the construction of the Eddystone Lighthouse in England, engineer John Smeaton rediscovered that lime and clay are required ingredients to form an effective cement. After scientific research by French engineer Louis Vicat in the early 1800s, a number of patents were awarded in the following years, culminating with Joseph Aspdin’s famous 1824 patent for what he called ‘Portland’ cement, being similar in appearance to the high-quality stone from the UK’s Isle of Portland. Over the following 50 years, Ordinary Portland Cement (OPC) gained increasing market acceptance in major engineering works including canals, sewers and ports.
The ‘secret’ of the ‘recipe and baking instructions’ for cement had not stayed secret for long, and producers sprang up in Europe and in the Americas before long, all at first using the original bottle-shaped vertical batch-based kiln. However, from around the 1880s, continuously-operated rotary kilns started to be developed, primarily in the UK and US, as well as more effective crushers and grinding equipment. Cement from rotary kilns was found to be much more reactive than from bottle kilns, and it was found that adding gypsum to the cement could retard setting times to make it more workable.
Throughout the early 20th century, cement manufacturing spread to many areas of the world, with locally-based enterprises establishing factories to supply local demand. Alongside establishing networks of local plants, some companies started to buy or build plants outside their home countries, becoming the first multi-nationals, foremost among them being the UK’s Blue Circle (the first multi-national, with investments in South Africa and Canada from 1912), Switzerland’s Holderbank (now Holcim, with early investments in Belgium and the Netherlands); France’s Lafarge, Heidelberger Zement (now Heidelberg Materials), Mexico’s Cemex and others.
American (Fuller), Danish (FLSmdith) and German (KHD Humboldt Wedag, Polysius) technology suppliers were becoming well-established, alongside English, French, Belgian and Japanese suppliers (and others), all of which drove technological developments. Wet and semi-wet rotary kilns predominated until the late 1970s, at which point the Oil Crisis caused fuel costs to soar, and which led to the widespread adoption of precalciner vessels, which took work out of the kiln and which improved both efficiency and kiln throughputs. Coolers, mills (particularly vertical roller mills), separators, instrumentation and control systems all made leaps forward in sophistication through the 1980s and 1990s. In this period, the first trials of alternative fuels were undertaken in Europe and Japan.
Through the 1970s - 1990s, the multinationals went on a buying spree, adding whichever plants they could, as opportunities presented themselves (including with the dissolution of the Soviet Union, privatisations in Eastern Europe, and the collapse of the Asian cement industry (in mid-boom in 1997). Rationalisation of the ‘western’ multinationals is ongoing (Lafarge ‘ate’ Blue Circle, and was in turn ‘eaten’ by Holcim), but Chinese and Indian cement companies now crowd the global Top 10. Old economies have cut manufacturing capacity, while growth has shifted to developing economies.
Today, fuel and energy efficiency, decarbonisation, carbon capture, smart maintenance, digitalisation and artificial intelligence are the main trends. However, profitability is, was and always will be, the main aim of the global cement industry.
Waldemar Klemm - Cement manufacturing - A historical perspective (Innovations in Portland Cement Manufacturing, PCA 2011).
Retrospective: Cement industry development - Joachim Harder, ZKG
Global Cement Directory 2024 - Articles by Gregory Bernstein & Lawrie Evans
