IIn April 2019, the Cementos Argos’ new calcined clay production plant started its operation. Located at the Rioclaro site, in Colombia, this line was designed following the D-Pozzolan®️ technology, which involves several patents of Dynamis. Other than the pyroprocessing, the most visible part of the plant, Dynamis took part of the entire project development activities, in close partnership with Argos. These activities started with initial laboratory tests, that developed into an engineering project and culminated in equipment supply and technical assistance during erection and start-up.
The most impressive point to stand out from this plant is the color changing technology. It is very interesting to see the reddish clay being fed to the dryer, changing its color inside the rotary kiln and finally leaving the cooler as grey calcined clay. This color-change technology is part of the D-Pozzolan® Technology, a complete solution carefully designed by Dynamis to meet the specific needs of the clay calcination process. The grey color of the calcined clay allows high substitution rates and important reductions in the clinker to cement ratio, in the cost and also in the CO2 footprint of the cement produced.
The quarry is connected to the industrial plant by trucks. The raw clay received at the plant is processed by deagglomerators which are responsible for obtaining the ideal clay grainsizes for the D-FDryer (the Dynamis’ flash drying system). Inside the dryer, the solid particles are dragged by the cocurrent hot gas stream, making it possible to obtain high heat and mass transfer coefficients in a relatively small equipment and with small footprint. The preheated and dried material dragged by the gas stream is separated from the flue gases by a set of cyclones.
The hot gas for material drying comes from the kiln and is complemented by the D-HotGas, the Dynamis’ hot gas generator designed for 100% coal or petcoke. It is important to have the correct gas flow at the drying system to enable clay particles dragging. Furthermore, the hot gas generator complements the thermal load for material drying.
The dry clay collected by the cyclones is fed to the rotary kiln. At the feeding chute, the clay is mixed with coal particles of controlled grainsizes which act as a reducing agent inside the kiln.
The rotary drums (kiln and cooler) used in this project came from deactivated units and were adapted by Dynamis. This utilization of decommissioned equipment was a premise stablished by Argos.
Dynamis D-Pozzolan®️ technology, with the application
of a D-Gasifier that operates with solid fuel (coal or petcoke), provides the
very tight control of temperature and oxygen content throughout the kiln, which
are fundamental points for obtaining thermally activated clay, for assuring its
color change and for achieving the desired quality. The
D-Gasifer is patented by Dynamis.
The product from the kiln is forwarded to a rotary cooler. As for the kiln and the dryer, it is important that material cooling is carried out in a controlled atmosphere so that the gray color obtained at previous stages does not reverse. Thus, the airflow for cooling is minimized. Lifters installed inside the cooler maximize the heat exchange coefficients between air and material. But the cooling process must be complemented by water. Dynamis installed water channels over the cooler promoting the formation of a water film on the shell. Thus, the low temperature of the calcined clay at cooler outlet is obtained by both the airflow inside the rotary drum and the flow of water outside the cooler shell. Finally, if any unexpected condition occurs and the calcined clay temperature exceeds the maximum set value, emergency lances spray water inside the cooler.
All these innovations applied in the largest calcined clay production plant in the world constitute Dynamis D-Pozzolan®️ Technology, which is the result of intense search for innovation, partnerships with renowned players, intense investments, solid studies and large efforts of high-skilled engineers, prepared to solve problems and deliver results.
Learn more about our solution D-Pozzolan®️ to reduce cement production costs!