Challenges and Performance of Filter Dusts as a Supplementary Cementitious Material

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• The global economy predominantly follows a linear model, necessitating a shift towards a circular economy.
• Reclaiming anthropogenic deposits, such as industrial waste, is crucial for sustainable resource management.
• Filter dusts from calcined clay production represent a significant, underutilized waste stream.

Purpose of the Study:

• To investigate the potential of filter dusts from German and Argentinian calcined clay production as supplementary cementitious materials (SCMs).
• To compare the properties and pozzolanic reactivity of untreated and calcined filter dusts with the base industrial product.
• To assess the feasibility of utilizing these waste materials in cementitious applications, contributing to a circular economy.

Main Methods:

• Characterization of two filter dust samples (German and Argentinian) from calcined clay production.
• Comparative analysis of untreated and calcined filter dusts, including physical properties and pozzolanic reactivity.
• Evaluation of the impact of calcination temperature on specific surface area, water demand, particle size distribution, and reactivity.

Main Results:

• One filter dust sample demonstrated suitability as a full supplementary cementitious material (SCM) without additional treatment.
• Pozzolanic reactivity of the suitable material was found to be comparable to that of fly ash.
• Materials were classified into reactive pozzolans and filler materials with minor pozzolanic activity.
• An inverse relationship between calcination temperature and specific surface area/water demand was observed for both material groups.

Conclusions:

• Filter dusts from calcined clay production can be effectively valorized as supplementary cementitious materials (SCMs).
• Specific dust samples exhibit significant pozzolanic reactivity, offering a sustainable alternative to traditional SCMs.
• Calcination temperature critically influences the physical properties and reactivity of these waste materials, enabling performance optimization.