Process-integrated recovery
of bypass dust
residue-free
The process is operated free of residues and waste water, using the excess waste heat from the bypass gas.
economically
By reducing it to what is technically necessary, a high level of economy is achieved without sacrificing the functionality of the bypass system.
CO2-Bonus
The calcined and desalinated bypass meal is completely recovered for the kiln process, which also reduces the CO2-Balance of the rotary kiln is relieved accordingly.
Cl discharge
The chlorine load of the bypass meal is at least 95% washed out of the dust, so that the Cl discharge of the bypass system is guaranteed.
Procedure sketch
Significant amounts of bypass dust are generated in the production of cement clinker. A certain proportion of this dust can be used as an additive in the cements. However, the use of quantities of this recycling route is limited for reasons of quality assurance, so that a volume flow that has increased in recent years can no longer be efficiently recycled. The transportation and partial dumping of the excess bypass dust amounts on the one hand causes considerable costs, on the other hand the bypass dusts have a similarly high energy and CO2-Footprint as the cement clinker produced. It is therefore desirable, both from the point of view of environmental protection and resource efficiency, and for economic reasons, to utilize the bypass dusts to a higher value. The current use is to be classified as unsatisfactory for ecological as well as economic reasons.
The newly developed process provides a remedy here and enables an ecologically and economically attractive way of recycling the bypass dust, in which, through a washing process, on the one hand a marketable product (potassium chloride) and on the other hand a calcined and CO2-free raw material components for the clinker burning process are obtained. The process is designed as a sub-component of the waste heat recovery from the clinker burning process, as it uses excess waste heat from the kiln process to dry the potash salts obtained and is therefore economically attractive and can be operated without wastewater.
An industrial test is currently being prepared for the washing process described in cooperation with the Association of German Cement Works and a well-known German cement manufacturer, which is intended to ensure high availability and a marketable quality of the recycled products.