Combined chemical-beneficiation processes of valuable components extraction from coal burning wastes

Abstract

This paper demonstrates the variety of the composition and properties of the ash and slag combustion products depending on coal type, grade, and conditions of combustion. Typical integrated processing methods of coal ash from Russia’s different regions are presented based on concentration technology: collection of aluminosilicate microspheres; flotation of the unburnt coal organic mass; magnetic separation to produce iron concentrate; flotation of the aluminosilicate product of non-magnetic fraction; gravity concentration recovering valuable trace elements into the heavy fraction and the aluminosilicate product into the light fraction; chemical treatment to recover various metals (germanium, gallium, scandium, gold, etc.). To recover gold from stack emissions and ash, an experimental process is proposed for liquid-phase condensation of volatile gold from stack emissions by live steaming followed by purification of the solution and sorption of gold by activated carbon. Process for gold capture from stack emissions is proposed using solid-phase condensation.