Calcined clay in cement: Use more clay, less clinker
Reduce the clinker factor down to 50 percent, save money, emit less CO2 – with activated clay
Due to tough market conditions more cement producers want to reduce the clinker factor and to increase the volume of Supplementary Cementitious Materials (SCMs) in their products. Calcined clay offers a sustainable and cost-effective alternative. With its polysius® activated clay technology, thyssenkrupp is providing an innovative solution for the industrial use of clay as an SCM. The technology supports fuel substitution rates of up to 100%. If desired, our solution puts an end to the terracotta-color of calcined clay cement.
One-stop solution for raw material changeover: polysius® activated clay
We offer cement producers comprehensive support in consulting, project development, implementation and operation. This includes
If a promising deposit is found, it must be determined whether it is within a reasonable distance of the processing facility and of an adequate volume to supply a minimum 200 tpd plant. This involves obtaining a representative material sample – no easy task in the case of heterogenous materials.
Once availability is ascertained, the next step is to assess the marketability of the potential end product. Ternary blends, such as Limestone Calcined Clay Cement (LC3), have not yet been standardized in many markets. However, even where no norms have been introduced, it may still be possible to secure a permit.
Finally, a business case must be drawn up as the basis for the investment decision. Project-relevant parameters include the cost of clinker, fuels and electricity, as well as the current supply of other additives.
There are two potential plant setups for processing activated clay. Since both variations have their own advantages and disadvantages, we provide detailed advice to interested plant owners. The final decision depends on the individual weighting of a range of criteria.
A strong argument in favor of this type of plant is that it can be retrofitted in a relatively simple way by converting an existing installation. Electrical energy demand is also relatively low, while fuel consumption – by far the most important cost driver – is comparatively high. The choice of feed material and the clay quality require increased attention, with lumpy feed material and pure clays preferred. Compared to option #2, this process configuration has a lower throughput. Controlling the activation temperature and material coloring is challenging, and product quality may be inconsistent.