Preparing High-Strength Formed Coke from Coke Breeze Using a Composite Binder: Complementary Integration of Phenolic Resin Binding and Coal Tar Pitch Carbonization

Coke breeze, a solid waste generated during coke production, transportation and utilization, possesses physicochemical properties akin to metallurgical coke except for its finer particle size. Recycling this material offers an effective route to conserve and reuse coal resources, yielding notable environmental and economic benefits. In this study, a composite binder composed of phenolic resin (PR) and coal tar pitch (CTP) was developed for producing high-strength metallurgical coke substitutes from coke breeze. This strategy complementarily combines the excellent binding and curing properties of PR with the superior high-temperature carbonization performance of CTP. Thermal and structural analyses elucidated distinct pyrolysis characteristics and functional group distributions between the two binders, providing a theoretical foundation for their complementary interaction. Systematic investigations into briquette strength, performance, and microstructure established that the optimal composite binder dosage is 15 wt.% of coke breeze, with a CTP-to-PR mass ratio of 7:3. This complementary system substantially enhanced the compressive strength of the formed coke, reaching 37.73 MPa after carbonization at 1000 °C, and improved its thermal stability, as reflected by a Coke Strength after Reaction (CSR) of 41.21%. Compared to the individual binders, the composite binder exhibited superior consolidation efficiency and structural integrity, presenting a promising approach for solid waste valorization and sustainable coke production.