Development of a High-Temperature Macro-TGA for Industrial-Scale Calcination and Sintering of Magnesite

Abstract

Refractory materials such as magnesia (MgO) and doloma (MgO - CaO) play a critical role in high-temperature industrial processes due to their exceptional thermal stability and chemical resistance. Their production relies on controlled calcination and sintering processes, where parameters like temperature, heating rate, and atmosphere directly influence the final material properties. To better understand and optimize these processes, we pursue an integrated approach combining laboratory-scale thermogravimetric analysis (TGA), computational fluid dynamics (CFD) simulations, and the development of a novel high-temperature MacroTGA system. In this manuscript, we present an analysis of the thermal behavior of materials used in the production of refractory materials, based on laboratory-scale thermogravimetric (TG) analyses. Lab-scale TGA and differential scanning calorimetry (DSC) experiments were conducted on various magnesite- and dolomite-based raw material fractions to assess their decomposition behavior and thermal characteristics. The results provide insights into reaction kinetics, mass loss, and enthalpy changes during decomposition, forming a foundation for the development of future MacroTGA experiments. Additionally, we introduce a computational fluid dynamics (CFD) approach for modeling thermal decomposition behavior. The CFD model was developed using a Euler-Euler approach to simulate thermal decomposition in porous media under controlled conditions. The model includes diffusive transport through the porous sample and gas-solid reactions based on Arrhenius-type kinetics. Preliminary results of simulating the lab-scale TGA experiments show the potential of the employed approach and highlight the necessity to determine sample specific reaction kinetics in future work with a novel high-temperature MacroTGA, that is currently in development.