This article is the first in a series of four that will look at the prevailing trends in the global cement sector over the past 40+ years, each with sections on technology, energy and resources, products and corporate trends
From the recognition in the 1970s that fossil fuels were going to become expensive - through an ever-increasing focus on safety and product quality, higher capacity operations and advancements in transportation - to today’s acknowledgement that the current CO2 footprint is not acceptable, the cement industry is in a state of constant positive transformation. New technologies, products, methods of work and partnerships with stakeholders help it to innovate, to improve and to build better. There are great lessons to be learnt from history... and the cement industry is no exception.
1 Technology and Operations
The oil crisis of the late 1970s forced the cement industry to recognise that fuel costs were going to play a critical role in decision-making in the 1980s. The last energy-intensive wet kilns, as well as the semi-dry Lepol kilns installed in the late 1970s became the Betamaxes of the cement industry. Even the demand for water in slurry could be an issue - consuming millions of litres of scarce water - if those technologies were not to be replaced.
The high cost of immediately replacing these installations, some of which had become obsolete almost as soon as they came online, put a high emphasis on what was technically possible to improve them. Modifying wet kiln chain systems to achieve higher production and lower fuel consumption were common approaches. Most cement companies had large engineering workforces at the time and made gradual, rather than step-change improvement.
The greatest advance in kiln technology during the 1980s was the commercialisation of precalciner kilns. The basic principle of the precalciner had existed for years. In West Germany, this initially focused on expanded kiln risers, as well as the use of both conventional and some limited types of alternative fuels in those risers.
However, the main mover for this technology advance was Japan, where there had been rapid growth in cement demand from 20Mt/yr in the 1960s to around 80Mt/yr in the 1970s. The preheater kiln had been successfully introduced from Germany during the 1960s, but the rapid demand for increased scales of production meant the biggest preheater kilns in Japan reached diameters up to 6.2m. These large diameters initially led to disastrously poor kiln refractory life as well as a push for more innovation – this time by the large and precise equipment manufacturers, combustion experts and material scientists. In Japan the approach of separately calcining limestone in shaft kilns and then mixing it with the secondary materials before the kiln stage had achieved notable increases in output from conventional kilns of all descriptions. Now, with preheater kilns, the same opportunity existed. By taking work out of the kiln and shifting it to an integrated precalciner vessel, much higher production volumes could be achieved from a given kiln size. This technology spread rapidly through Japan.
Initial adoption outside of Japan came with US equipment suppliers, as Allis Chalmers and Fuller became licencees. European equipment manufacturers picked up on the idea and, from as early as the start of the 1980s, it was rare to install new plants with anything other than precalciners. There was also a high demand for conversion of existing plants.
An altogether quieter revolution was also taking place in raw milling. Vertical raw mills had been developing in scale and reliability through the 1970s but ball mills were still a common choice for raw meal preparation in new plants. However, by the start of the 1980s, the combination of large scale vertical raw mills, with their optimum drying capacity and lower specific power consumption, had become the technology of choice.
Cement milling was not spared from the technological leap forward. There was a rapid spread from Japan of the third generation separators that offered both increased ball mill efficiency and improved product quality. Third generation separators were quickly adopted by the most innovative manufacturers to offer better quality control and product differentiation. Roller presses also appeared on the scene, usually to boost outputs from ball mills. However, the early adopters often found reliability to be a challenge, which diluted initial enthusiasm for the technology.
Waste heat recovery systems, using the available heat in preheater and cooler exhausts to generate power, were also developed in Japan. The then unique combination of large scale plants and high power costs favoured this development in Japan, so much so that the technology stayed at home for the next 20 years.
The 1980s were also the decade when cement manufacturers essentially gave up on in-house development of manufacturing equipment and finally left the stage to original equipment manufacturers (OEMs). In order to keep up with the latest supplier trends - as well as to incorporate a balanced view, ensure the expertise flow and development work between the industry and the suppliers - there was significant growth in technical associations, such as CETIC in Europe, and partnerships for technology development also started to grow. The best operators were thirsty not only to keep up to date but also to achieve a competitive advantage through innovation.
Among the technologies that attendees had to learn about were the rapidly-developing opportunities in instrumentation technology, an area of the plant that had historically had less emphasis placed on it, certainly compared to the ‘big ticket’ items. There were myriad opportunities to be exploited. Process engineers were happy to see the death of the Orsat apparatus, replaced by portable oxygen and carbon monoxide analysers. Kiln shell scanners, NOx and SOx, XRD, burning zone and cooler cameras all advanced industry knowledge. The era of the ‘kiln burner,’ staring intensely into the kiln burning zone in their blue glass visors, was over, as central control rooms were proudly constructed, sometimes far from the kilns themselves.
2 Energy, emissions, alternative fuels / materials
At the beginning of the 1980s the dominant fuels in cement production were coal and heavy fuel oil, with the oil crisis of the 1970s having driven the industry away from oil. A cheaper option, petroleum coke, was available, but the main source was in the US, where coal was relatively plentiful and low cost. Nonetheless, the 1980s saw a trend to increased use of petcoke. With this came the challenge of grinding the petcoke finely enough for combustion. Learning to manage the chemical build-ups and the effects on cyclone aerodynamics that this led to soon followed. Investigation and control methods of the volatile cycles, temperature control, precision in mining practices to stabilise the mix design and reduce chlorine and alkalis started to build the foundation of the modern cement process chemistry. High pressure water jets and air cannons appeared and subsequently evolved into vital and advanced automated tools.
Alternative fuels were also on the horizon. The first full-scale alternative fuel installations had already started in the 1970s. For example, Blue Circle’s now-defunct Westbury plant had two wet process kilns in 1976. Equipment for the size reduction of the refuse derived fuel (RDF) was basic by modern standards but the challenge of using a relatively poorly prepared, wet, heterogeneous fuel in the burning zone of the kiln remains the same today in many markets. Unfortunately, the loss of production from the kilns was such that by the early 1980s the plant had reverted to 100% coal - the more sophisticated technologies were yet to come.
However, the 1980s also saw more serious moves to alternative fuels. Tyres, both whole and as chips, were often the first alternative fuel of choice, but others, including solvents, waste oils and smaller quantities of secondary recovered fuel, soon followed. The main movers were in Europe and Japan, driven by cost reduction. The incinerator lobby quickly began to work against the cement industry and the alternative fuel suppliers began the long game of pushing prices up. With CO2 barely on the horizon and with a paucity of precalciners, which are more tolerant of poor quality alternative fuels, and competition from the traditional incinerator wste industry, European efforts towards alternative fuels stalled until the next decade, while Japan steadily progressed.
The same was not true of stack emissions. In 1980 most cement plant emissions issues still revolved around dust. The revolution in dust controls led to perhaps the most visible improvements of the sector’s image and positive recognition from local communities. By the early 1990s the industry had literally cleaned itself and the forests around old plants became green again.
As standards tightened, the debate on the future of the electrostatic precipitator versus the bag filter began in earnest. Towards the end of the 1980s the first regulations on NOx and SOx were introduced for the industry in Europe. Although the limits were initially relatively generous, there was now a recognition that things were changing and the industry needed to react. The beginnings of the path to ‘green cement’ had truly commenced.
3 Products
The 1980s saw an initial expansion in the use of fly ash and granulated blast furnace slag (GBFS), and the first focused efforts to accommodate such materials by cement and concrete chemists. The foundation of this aspect of the material science of the modern era also started to emerge both in academia and in the leading corporate technical centres. This was led by the heavily industrialised countries in Europe, Japan and in North America. Here, these materials were available, and the appetite for innovation was strong. The industry could see the benefits in cost and quality but also understood that supplementary cementitious materials (SCMs) represented a growing opportunity to widen the product range, challenge more sophisticated engineering needs and, ultimately, to decommoditise the product range. The era of 95% clinker cement was coming to an end and the clinker factor started its gradual decline. Already in the 1980s, as the growth of the ready mix concrete industry offered the opportunity to take the GBFS and fly ash directly to end users, these trends started to positively influence the market.
Although the opportunity to diversify the product range had been evident for a number of years, it is mainly today with the acceptance of the need to reduce CO2, that such early efforts have become a focus of the most serious research, procurement and supply chain solutions. The results of the 1980s work are still evident now, where the industry is accelerating its solutions to reduce CO2 even further. In some markets, cement producers in the 1980s developed partnerships with progressive power and steel companies to recycle fly ash and GBFS supplies sufficiently to include them in their own cementitious products. However, in some countries it came decades later. GBFS and fly ash were simply stockpiled by the power companies, resulting in enormous costs to deal with them later down the line. It is a relevant lesson. To paraphrase a famous saying ‘the late adopter pays twice.’
As the range of cement products broadened, it was clear that understanding the strength behaviour and durability of cement in concrete needed to be advanced. Cement standards were evolving around the world, almost all reliant on the recipe approach by defining the components in each cement type produced. It was very much a ‘cut and paste’ approach for many country standards around the world, with most taking elements of the European or US standards as they evolved. Standards, including quality management systems also became useful to cement and concrete customers to differentiate quality suppliers from others. Such standardisation efforts will only continue to escalate in the future.
All of the impacts of such elements as magnesia (on expansion), chloride (on reinforcement corrosion) and C3A (on sulphate attack) were well known by the 1980s, but the emergence of ‘concrete cancer,’ the deleterious expansion that occurs due to the alkali-silica reaction, was not well understood. With increasing focus on concrete carbonation and durability, there were concerns which needed to be resolved, creating the next stimulus to concrete experts in academia and in the industry – to this day.
Special products such as masonry, coloured masonry and aluminates were also growing. Geopolymer cement, in the form of Pyrament, made an appearance in the 1980s in the US. Geopolymers had been known since the 1950s and made a brief commercial appearance as Purdocement in Belgium. However, the era of CO2 had not arrived by the 1980s and geopolymers did not succeed in creating as much commercial or business development attention as they receive today.
4 Corporate – Models and Economies
Of the then ‘majors’ of the 1980s, Blue Circle had been the earliest to expand multinationally. Its initial investments had been in 1912 in South Africa and Canada, parts of the then British Empire. However, a plant in Mexico was also purchased, as the result of a chance encounter between a British export cement sales representative and a Mexican customer. The latter remarked that an opportunity existed to purchase the plant, as its US-based owners were departing due to the Mexican Revolution. Risk analysis was less considered back in those days!
Following those investments little further happened until the 1950s, when Blue Circle followed the Commonwealth route into Australia, New Zealand, Malaysia, Nigeria and Kenya, initially remaining an exporter of cement from the UK. But that policy was about to change. When Sir John Milne, the then chair of Blue Circle, sagely remarked “Geologically, so far as I am aware, it is the case that there are only two major countries (Ghana and Bangladesh) in the world which lack limestone deposits for cement manufacture.” In other words cement could - and would - be produced where the raw materials were located in the future. This thinking drove an expansion into the US and other opportunities were investigated via technical consultancy services. However, by the end of the 1980s the Blue Circle strategy had been somewhat reversed and holdings in Australia, Mexico and New Zealand had been sold.
Holderbank (now Holcim) was also an early expander outside of its home in Switzerland. The export strategy was very limited from a Swiss base. By 1926 Holderbank had already invested in plants in Belgium and the Netherlands. This was followed by Egypt and Greece and other opportunities. By the start of the 1980s the US also beckoned, with the major acquisition of Ideal Basic Industries, followed by several more companies across the Americas.
Lafarge had progressed internationally too, with expansion into North Africa and also into the UK with high alumina cement in the 1920s. Further significant investments outside of France had to wait until the 1950s and 1960s, in Canada and Brazil. During the 1980s Lafarge was expanding rapidly on the international stage on several fronts. In 1981 it took over General Portland in the US. By the late 1980s Lafarge had also moved into Germany as an early statement of its pan European ambitions.
Heidelberger Zement also made its first major step with the 1977 purchase of Lehigh in the US. Japanese cement companies preferred to export from Japan and most did not expand production internationally. Fragmented ownership, lack of scale, technologies or innovative spirit in many other cement companies detracted from the necessary leadership, organisation and capital required to ex-pand into riskier investments outside of their home countries. In fact, some small companies remained successful for decades. It was already realised in the 1980s that cement players should always maintain a careful balance between a network of well managed operations focused on safety, customers, employees, frugal operations and local communities. Corporate or external support was also seen as vital, mainly when it came to capital, supply and technologies.
Throughout the 1980s the large corporations were driven not only by the desire to expand but also by the need for efficiencies. This dynamic became a driver throughout the industry. The energy crises of the 1970s had changed the business environment and shown that, more than ever, energy costs were going to be a key feature of competitiveness. Maintaining a network of small scale wet process plants was the route to extinction. Capital investments to change processes, to increase productivity through scale and automation and to enlarge capacities at key plants became the norm. Benchmarking had entered the vocabulary of cement companies by the start of the 1990s – the era of process efficiency, when the new giant single kilns and mills had to produce, store and ship millions of tonnes of cement to the more and more technically demanding users of concrete 24/7, sometimes at utilisation rates above 90%.
Model
In the next issue, the authors explore the factors that shaped the cement sector in the 1990s, including the modernisation of the industry in Eastern Europe following the collapse of the USSR and rapid demand growth in the Far East. The emergence of new technologies – from XRD and cross belt analysers to giant 12,000t/day kiln lines - new products and new marketing approaches will also be discussed.
About the authors
Lawrie Evans founded EmCem Ltd, a UK-based cement consultancy, in 2014. Lawrie previously worked for more than 40 years at Italcementi, Heracles Cement and Blue Circle in the UK, Greece, the US and Italy across optimisation, management, operations and chemical engineering.
Gregory Bernstein has worked for Holcim for more than 30 years. He met Lawrie Evans in the UK in the early 1990s, before taking on process, project, strategy, well cement and business development roles in the UK, Europe and the US. He is currently developing worldwide partnerships to accelerate sustainable construction solutions.
Image credit: The former Blue Circle and Lafarge Westbury cement plant in Wiltshire, UK. Licensed for reuse under a Creative Commons Licence (CC BY-SA 3.0)
