Sustainability

In 2002, the social partners in the German cement industry signed an agreement on sustainable development within the sector, thus laying the foundation for the sustainability initiative of the German cement industry. This was the first industrial agreement of its type. The sustainability initiative is supported by the industrial unions for building-agriculture-environment (IG BAU) and mining, chemicals, energy (IG BCE), as well as by the Socio-political Working Group of the German Cement Industry (SPADZ) and the German Cement Works Association (VDZ). The social partners work together on topics of central relevance to the sustainable development of the industry.

After almost 20 years the initiative can look back on a number of successful projects.

Important areas of activity include:

• Finding a balance between the needs of raw material extraction, safeguarding employment and nature conservation
• The reduction of CO₂ emissions, the enhancement of energy and resource efficiency and the conservation of natural resources
• Qualification schemes and supply of information for cement plant employees
• Industry 4.0 – digitisation and big data

The aim of all these measures is to raise and maintain awareness for sustainability in the industry. The social partners will be continuing their efforts to reconcile ecological, social and economic needs in the German cement industry even better in the future. For more on the sustainability initiative, visit: www.zement-verbindet-nachhaltig.de

Demographic change and the high average age of its employees are major challenges facing the cement industry. One of the ways in which the industry is confronting this situation is by intensifying its training activities. There is a demand for qualified specialists in many fields, including electronics and mechanical engineers, administrative personnel, building material testers and laboratory assistants.

Process technology innovations and an increasing degree of automation have led to a massive rise in the productivity of the workforce since the mid-1990s. It is therefore becoming ever more essential for the workers in the modern, high-tech cement industry to be highly qualified. Alongside training, personnel development is thus one of the primary tasks to be tackled by the companies. Great importance is attached to ongoing in-house training activities employing modern qualification methods such as eLearning.

As they are often in rural areas, the production sites of the cement plants are some of the most significant employers and providers of training. They contribute to the regional economy by placing orders with local tradesmen and companies. Together with all its associated business areas, the industrial cluster specific to the cement industry employs well in excess of 60,000 people in Germany.

The constant enhancement of occupational health and safety at the plants is a central concern in the cement industry. Specialist committees of VDZ work together with experienced engineers and industrial safety experts to develop measures aimed at improving health and safety standards. The common objective of all these efforts is to ensure the safety of workplaces and equipment, whilst at the same time promoting a safety-conscious attitude amongst the workforce at the cement plants, providing regular information on how to improve industrial safety and encouraging personnel to constantly check up on safety at the workplace. This approach has enabled the German cement industry to significantly reduce the number of accidents at the plants (refer to accident statistics). In keeping with the "Vision Zero" concept, the ultimate goal is to create a world where there are no industrial accidents or work-related illness.

The VDZ industrial safety competition, which awards an annual prize to the plants with the lowest accident frequency rates, has been providing valuable motivation for many years now. These awards can be seen at prominent locations such as canteens and entrances at a number of plants throughout Germany. They provide the workforce with a constant source of motivation to maintain good safety standards. Because, as all the prize winners will confirm, there is nothing more difficult than producing excellent results year after year.

Development of occupational health and safety at the cement plants

Over the course of the past few decades, the German cement industry has become an important partner for the domestic circular economy. This involves the use of alternative raw materials and fuels at various stages of the cement production process. Most of the materials employed are selected treated waste and residual materials which are not suitable for re-use in other applications or recycling. Utilisation of these makes it possible to replace large quantities of fossil fuel (e.g. coal) and primary raw materials (e.g. limestone) whilst also, depending on the type of substitute fuel, reducing CO₂ emissions from fossil sources.

So-called alternative fuels now account for more than two thirds of the fuel required by the German cement manufacturers and the figure is still rising. These include treated industrial and municipal waste, sewage sludge and used tyres and have a number of advantages to offer. For instance, they are a substitute for fossil fuels such as coal, oil and gas. As well as cutting the level of CO₂ emissions, the ashes from the combustion of these materials also form essential constituents of burnt clinker and can thus be re-used. This method, which is unique among industrial processes, is also referred to as co-processing. Energy and material recycling thus take place more or less simultaneously. All constituents are fully re-used in this process.

Roughly 16% of the raw materials required for cement production are accounted for by alternative raw materials. In the burning process for cement clinker production, these include sewage sludge from drinking water treatment, waste foundry sand from metalworking and fly ash from coal-fired power stations. In cement grinding considerable use is also made of blast furnace slag, which occurs as a by-product in iron making. The utilisation of these alternative raw materials makes it possible to save more than 11 million tonnes of limestone per year. In view of the overall demand for raw materials for cement production, the cement industry will however continue to depend on a reliable supply of primary raw materials in the long term as well.

Concrete is a building material which makes for sustainable construction in many different ways. Starting with the natural raw materials water, sand and gravel. These are mixed with cement to produce concrete. All are available locally and only have to be transported over short distances. Modern concrete works employ resource-preserving and energy-efficient production techniques - using alternative recycled raw materials wherever appropriate. Concrete also offers a lot of sustainable aspects for building: it is extremely durable and robust, whilst providing sound and thermal insulation. In addition, it allows greater flexibility with regard to the design of structures. Concrete can make a positive contribution from the point of view of climate protection as well. CO₂ is extracted from the air through the carbonation of concrete components, for example.

Provided it is all of the same type, concrete is very easy to recycle. This applies to fresh concrete, for instance, which is taken back to the plant by truck mixers. Any material not used can thus be returned to the production process. These return quantities constitute approximately 2.5 per cent of the total produced by a concrete plant. Hardened concrete is also suitable for recycling. Concrete rubble is obtained from the dismantling of buildings, for example, and then comminuted with a crusher. The resultant aggregate is used in turn for concrete production and so acts as a substitute for valuable primary raw materials such as gravel and sand.