Reshape your footprint

Find out everything about C/Clay technology
- made by LOESCHE - and the associated advantages for your business.

LOESCHE advises you comprehensively and will support you on your way to success. 

C/Clay is our new label for LOESCHE's overall process for the production of calcined clay.

Calcined clay is an environmentally friendly supplementary cementitious material (SCM), that has massive potential for reducing CO2 in cement manufacturing.

C/Clay is part of LOESCHE's CO2 reduction strategy.


First the surface water and later the water in the intermediate layers are evaporated. This results in a transformation of the internal structure up to a (partial) amorphization of the material. This gives the clay a certain reactivity, which is then available for further use as an SCM and later in concrete. The quality of the clay is decisive here.

C/Clay technology consists of calcination and a grinding stage. Both are coupled in a state-of-the-art process.

C/Clay can be used to process all types of clays, regardless of moisture content, organic components, and grain size.

Particular attention was paid to the efficient use of energy and heat transfer with as little loss as possible.

As a grinding specialist, LOESCHE is committed to optimal grinding, whether by co-grinding with clinker or by separate grinding.

But C/Clay is more than that...


C-Clay flowsheet with rotary kiln

C/Clay flowsheet with rotary kiln


C-Clay flowsheet with flash calciner

C/Clay flowsheet with flash calciner


For Manufacturers

C/Clay technology is established and easy to use with low demand for infrastructure.

These are the benefits:

  • Alternative fuels burners are available.
  • Up-to-date heat recuperation/heat recovery is possible.
  • Simplified civil engineering is possible due to a flat construction.
  • Reduction of CO2 costs
C-Clay for Manufacturers



For material handling and performance

  • The regulation and adaptation to current material parameters (e.g., moisture and size of feed material) are quick and uncomplicated with C/Clay.
  • Depending on the quality of raw clay the performance of manufactured cements is at least equal to those made with fly ash or GGBFS instead of fly ash.
  • Efficient feed material preparation due to Loesche’s long-term experience.
  • Equal thermal treatment of the entire material

For the environment

  • C/Clay is able to reduce the CO2 footprint of manufactured cement down to 60% related to OPC.
  • In contrast to clinker, clay does not emit any material-specific CO2 during calcination.
  • Furthermore, the significantly lower calcination temperatures save a lot of fuel and thus also CO2.


Full-service for plant realization

  • Customized plant design
  • Delivery and installation of the complete plant


LOESCHE is able to supply the entire process equipment:

  • feeding system
  • calcination system (kiln or flash)
  • cooling system (grate / cyclone)
  • grinding system
  • heat recovery
  • conveying, dosing, storage

Scientific support at all levels

LOESCHE has its own laboratory / Technical Center for material analyses and works closely with leading building material institutes in Germany and worldwide.


LOESCHE C-Clay Packages


LOESCHE can develop the complete concept for your clay calcination. We offer individual testing packages, which we go through with you step by step to create a perfect product adapted to your needs.

Package 1: Basis analyses

  • Sample preparation
  • Initial testing of the mineralogical composition
  • Report of suitability for calcination

Package 2: Thermal activation ability

  • Pre-testing of thermal activation of the original material at several temperatures
  • Material analyses
  • Evaluation of calcinability
  • Comparison with other pozzolanic materials

Package 3: Research on binder and building material properties

  • Mortar testing according to EN 196-1 producing calcined clays
  • Grinding tests
  • Determination of the activity index

Package 4: Concrete properties

  • Concrete tests including durability
  • Concrete production according to a given recipe

Package 5: Large-scale trials on calcining and grinding

  • Calcination in a semi-industrial scale (flash calciner or rotary kiln)
  • Preparation of the original material depending on the delivery condition
  • Grinding in a pilot plant mill (co-grinding or separate) in the LOESCHE Test Center in Neuss, Germany



FAQ 1: What are useful clays for cement substitution?

For calcination and usage as SCM, kaolinitic, illitic and smectitic (montmorillonitic) clay soils are particularly suitable. Above all, the illitic and smectitic clays are cheap and readily available but have to be calcined with slightly more energy. Don't hesitate to contact us if you need clay expertise.

FAQ 2: Where are LOESCHE’s references for pozzolanic SCM's?

  • Nassau Itacimpasa, Brazil: temperature 500°C, throughput 14 tph
  • Argos Rio Claro, Colombia: temperature 800°C, throughput 60 tph

FAQ 3: Can we control the color of the final product?

Color control by reductive kiln conditions and fast cooling.

*Photo source: Dynamis Brazil

FAQ 4: Can the exhaust gas be cleaned?

We are able to eliminate both SOx, NOx and organic components from the exhaust gas stream. This is already a requirement in many countries.

FAQ 5: My company wants to calcine clay. How should we start?

If you are interested in clay calcination and do not know exactly how to start, you can simply contact us. We consider your needs, framework, parameters, and ideas in order to work out a schedule on how you can most effectively achieve profitable results with a high-quality product.


C/Clay - Reshape your CO2 Footprint