Influence of the lowering of melting point and viscosity of the clinker melt by ash of alternative fuels on sintering reactions and coating formation

Fuel ashes can lower the viscosity of the clinker melt. Therefore the effect of the lower viscosity of the clinker melt on the sintering reactions and the refractory lining of the rotary kiln is being investigated. The main focus of this study is to clarify if, due to the impact of the alternative fuel ash typical minor oxides, a sufficient sintering degree could be achieved also at lower firing temperatures. The study will have to identify in particular the effects on the chemistry and mineralogy of clinker and the impacts on cement quality and refractory materials. For such investigations raw meal-ash-mixtures will be produced. Different methods for the determination of melt amount and melt formation temperature will be tested in advance.

The clinker samples will be produced from ash doped mixtures in two different burning processes – static and dynamic. So it will be possible to determine influences of both processes on the clinker melt formation. Furthermore the quality of the clinker samples will be evaluated. In order to assess whether modified clinker melt formation is affecting the refractory lining in a rotary kiln, the coating formation and refractory corrosion will be investigate in the laboratory rotary kiln.

A data base will be compiled, that will enable cement manufactures to evaluate the influence of different fuels on the clinker melt formation and clinker quality. The manufacturers of refractory products will have an improved knowledge base on the influence of fuel ashes and the reduced operating temperature on the coating formation and the stability of their products in the rotary kilns.

Supported by

The IGF project 19221 N of VDZ gGmbH is supported by the AiF within the framework of Industrial Collective Research (IGF) of the Federal Ministry of Economic Affairs and Energy on the basis of a decision of the German Bundestag.


Dr. Jörg Rickert

Dr. Jörg Rickert

+49-211-45 78-283

+49-211-45 78-44427


10/2016 - 09/2018