Posted by Thilo Merkel - 12 November, 2018
As a construction material, concrete faces growing requirements – the same therefore applies to cement. One of the key objectives is to reduce the cost of cement production and the associated environmental burdens at the same time as improving efficiency. Thilo Merkel, Business Leader Cement Additives Europe explains the added value offered by chemical additives.
Thilo Merkel, what does the building industry expect from cement producers?
A transformation has been in progress in the cement industry for some time. This not only means considerable challenges but also new opportunities. On the one hand, cement factories need to become more and more efficient at the same time as reducing their environmental impact. On the other hand, customers are calling for increasingly high-quality, high-performance cement for more and more complex buildings and increasingly durable infrastructure facilities. Manufacturers therefore face the conflicting tasks of improving throughput, reducing costs, enhancing the performance properties of cement and cutting emissions – of course at the same time as complying with all the relevant regulations and internal quality standards.
And how are cement producers reacting to these challenges?
They are asking more and more questions. Technological developments and changes in society in general are causing companies to think about the long-term development of cement production. What fuel mixtures are to be used in future to generate the extremely high temperatures required? Where are the limits for low-clinker cement? What potential is there for CO2 reduction? These and other topics are being continuously discussed not only within the cement industry, but also, increasingly, by stakeholders outside the industry. Cement additive suppliers are thinking about the future role and potential of innovative chemicals in cement production and they are investing to a growing extent in research projects in this area.
What is the current role of cement additives at the plants?
Formerly, the majority of cement manufacturers attempted to optimize their production processes without additives. To a large extent, cement additives were seen as possibilities of correcting inadequate process efficiency or product quality. Nowadays, cement additives are used at almost all European cement plants and, thanks to the globalization of the cement industry, also to an increasing extent in emerging economies. Cement producers recognize the benefits of adding chemicals to the cement milling process. A holistic approach including both milling itself and the chemical activation of cement constituents in an integrated process would open up new possibilities and significantly roll back the current boundaries. With our recognized technological leadership in the field of concrete technology, Master Builders Solutions is committed to the cement industry and is assisting manufacturers in achieving their objectives with highly effective additives. Our MasterCem product family is based on decades of experience with cementitious materials.
What are the benefits of using cement additives?
The main benefits are with respect to costs and the environment: manufacturers need less energy for the milling process, which saves costs and reduces CO2 emissions. In addition, it is easier to integrate cement replacement materials, the capacities of existing cement factories are increased and investments in new plants are therefore reduced – which also represents a considerable saving in terms of cost and environmental impact. Higher production efficiency boosts capacities: the mills and separators work more efficiently, there is less clogging of the material and storage and loading become easier. Plants are stopped less frequently and maintenance cycles are reduced. Additives also play a key role in product quality. Cement made using a process of this type produces concrete with higher early and final compressive strength values, the rheology is improved and the additives compensate for the disadvantages of cement replacement materials. As regards environmental benefits, in addition to lower energy consumption as a result of higher efficiency, it may be possible to reduce the amount of clinker, produced with a high energy input, which is required. Furthermore, the more efficient use of existing quarries conserves natural resources.
What is the approach of Master Builders Solutions for the further development of cement additives?
Normally, additives are developed and tested in the laboratory using pot mills and other small mills. Although the data obtained gives a certain indication, it is not really representative. The problem is the size of the balls and their distribution within the ball mill. Small balls are lighter, the mechanical force applied to the substance being milled is significantly lower, the temperature is also lower and there is no particle separation. For this reason, Master Builders Solutions has invested in a pilot mill. This is a 1:10 scale version of a genuine cement ball mill and it offers realistic conditions without the tremendous cost of tests at a real cement factory. Our pilot mill is located at our development centre in Treviso, Italy and is used mainly for basic research and for the development of new cement additives in the MasterCem range. Although the mill is not really intended for this purpose it can also be used for specific customer projects following careful planning.
This mill is a key element of our research and development resources for cement additives. Using our pilot mill, we can mill cement and dose additives under constant process conditions and the particle size distribution is very similar to that obtained with an industrial-scale plant. For example, the effects of additives on energy consumption and the dosage rate can be monitored on a real-time basis. We can also produce enough cement for complete test series covering properties such as strength and rheology.
Apart from the pilot mill, what is necessary for the development of innovative cement additives?
In addition to the mill and the space it takes up, we also need space for large quantities of cement raw materials and the equipment, which was largely produced specifically for our purposes, needs to be properly maintained. In addition to a cement laboratory fully equipped with items such as slag breaker, small mills, low-temperature milling module, PSD laser analyser, ultrasonic screen and x-ray diffractometer, essential factors include our comprehensive know-how and the research and development expertise we have gained over the decades, at our research and development centre in Trostberg, our regional development facilities and our many local customer service laboratories. Our activities are based on a large team of chemists, physicists, mineralogists, geochemists and civil engineers. Within BASF, we can also call upon the globally networked know-how of interdisciplinary research teams. The network includes 1,900 cooperation arrangements with universities, research institutions, highly promising start-ups and partners in the industry.
With so much commitment, you obviously have a clear objective ahead. Could you briefly summarize it?
Especially in view of the growing cost efficiency and environmental compatibility requirements in the construction industry in general and in the cement industry in particular, chemicals will increasingly become an integral part of cement production. Cooperation between cement additive suppliers and cement producers will help in mastering future challenges. We must work intensively on the development of the next generation of cement additives. By investing in resources and equipment and with the support of the BASF Group’s excellent global research and development network, we intend to play a key part in this evolution.