Study on the Reactivity Activation of Coal Gangue for Efficient Utilization

Area of Science:

• Materials Science
• Geochemistry
• Chemical Engineering

Background:

• Coal gangue is an industrial byproduct with potential applications.
• Enhancing coal gangue activity is crucial for its utilization.
• Understanding activation mechanisms is key to optimizing its properties.

Purpose of the Study:

• To enhance the activity index of activated coal gangue.
• To investigate the activation mechanism of coal gangue.
• To optimize the mechanical and thermal activation processes.

Main Methods:

• Orthogonal tests were used to optimize the activation process.
• A genetic algorithm improved the Back-Propagation (BP) neural network model.
• Microscopic and mesoscopic analyses studied morphological and phase transformations.

Main Results:

• Calcination temperature had the most significant effect on the strength activity index.
• Optimal activation parameters were determined: 76 min grinding and 54 min thermal treatment at 749 °C.
• Mechanical and thermal activation effectively stimulated coal gangue's potential activity and increased active mineral content.

Conclusions:

• Coal gangue activation can be effectively stimulated through optimized mechanical and thermal treatments.
• The study identified key parameters influencing coal gangue activation.
• Thermal activation above 950 °C transforms kaolinite into highly active metakaolinite by removing hydroxyls and destroying the Al-O octahedron.