ABSTRACT Coal gasification fine slag (CGFS), a by‐product of the coal gasification process, consists mainly of irregular porous residual carbon and Si/Al‐rich inorganic oxides, giving it potential as a reinforcing filler. Froth flotation enables effective separation of the carbon and ash components, producing a carbon‐rich concentrate (CGFS‐C) and an inorganic‐mineral‐rich tailing (CGFS‐T). Nano Zinc oxide (ZnO), known for its small particle size and high surface reactivity, also acts as an efficient vulcanization activator in rubber systems. CGFS‐C and CGFS‐T were obtained through flotation, and a ZnO‐modified filler (CGFS‐T@ZnO) was prepared by chemical co‐precipitation using zinc acetate (CH 3 COO) 2 Zn as the precursor. The effects of CGFS, CGFS‐T, and CGFS‐T@ZnO on the vulcanization behavior, mechanical properties, and processing performance of natural rubber (NR) were investigated. Scanning electron microscopy (SEM) showed that when the mass ratio of CGFS‐T to Zn precursor was 1:0.50, ZnO nanoparticles were uniformly distributed on the CGFS‐T surface without evident agglomeration. At a CGFS‐T@ZnO loading of 10 phr, the NR composite exhibited the best overall performance, achieving tensile strength of 21.06 MPa, elongation at break of 686.1%, and Shore A hardness of 62.9. Loadings beyond 10 phr led to increased agglomeration, nonuniform dispersion, and reduced mechanical strength. When the CGFS‐T@ZnO content was between 5 and 10 phr, the nano‐ZnO modification enhanced the surface activity of CGFS‐T, improved compatibility with the NR matrix, and accelerated the vulcanization process. Overall, this work provides a viable approach for the high‐value use of CGFS solid waste and demonstrates strong potential for industrial application.
Ding et al. (Tue,) studied this question.