Demeter Technologies wishes to inform businesses of the opportunity of the creation of industrial production units for the pozzolanic binder- metakaolin, which can be used in all fields of construction.
Flash calcination technology, developed by Demeter Technologies, allows local businesses, for a manageable investment, the opportunity to become a major player in the production of hydraulic binders.
Following the agreement of the installation of an industrial metakaolin production unit, the technology transfer between Demeter Technologies and the business is implemented.
Find more details on the Technology Transfer page.
THE FLASH INDUSTRIAL PROCESS
The process of flash calcination comprises four phases defined by :
1/ a preparation phase
2/ a grinding/drying/selection phase
3/ uthe calcination procedure
4/ storage (of the finished product)
These steps represent the standard procedure of a Flash calcination industrial unit.
Phase 1 : the preparation
Soils containing kaolin have varied qualities in terms of plasticity, humidity or percentage of sand, to name but a few. After confirmation by Demeter Technologies regarding the suitability of a material for use in the production of metakaolin, the preparation methodology is studied. This preparation phase aims principally to prepare the product for the stages of its transformation into metakaolin.
Phase 2 : grinding / drying / selection
Depending on the characteristics of the clay in question, this phase aims to transform the base material into a dried powder, enriched through the elimination of all or part of its sand content by a process of grading. At this stage, different processes of grinding may be tested to evaluate the most effective method.
Phase 3 : calcination
After grinding and drying the clay, we obtain what we call the raw material. This product is preheated in a system of cyclonic separators using gases released from the calcination chamber.
The preheated product is brought to a temperature of around 700°C in the cyclonic oven called the calcination chamber (CC) using a burner.
The length of time in the calcination chamber gives the necessary time for the product to “cook” : this is in fact a dehydroxylation reaction, or in other words the elimination of water from the clay.
Once this transformation has taken place, the metakaolin is then separated from the hot gases in the cyclonic separator and then cooled in a system of successive cyclonic separators.
Before they are released into the atmosphere through the chimney, the preheating gases are filtered in a bag filter. Not having taken part in the reaction, these are reintroduced into the calcination process.
The hot air in the three cyclonic cooling separators, feeds the calcination chamber. The calcinated dust is also removed from this hot air using the bag filter.
Phase 4 : storage
The finished product is collected out of the filter at the level of the under-flow in the third cyclone of the cooler.