Cemented waste rock backfill enhancement via fly ash-graphene oxide hybrid under different particle size distribution

Cemented waste rock backfill (CWRB) is an important composite in supporting technology for safe and green production in mining. However, the mechanical performance of CWRB is highly correlated to cement consumption. This study utilized industrial graphene oxide (GO) and fly ash (FA) to create a high-performance, lowcost, and environment-friendly material for backfill. The results show that the GO-FA hybrid improves the microstructural matrix of hydrated cement by generating nucleation effects that refine the microstructure to a denser state and promote pore-filling effects that form barriers at pore throat junctions. This significantly reinforced the compressive strength (up to 53.6%) of the CWRB specimens. The reinforcing efficiency is more pronounced when using fine particle size distributions due to the lack of skeleton effect of gangue aggregates. By monitoring the acoustic emission and analyzing fractal properties, it can be further revealed that GO improves the integrity of CWRB material during loading. Compared to traditional backfill materials, the study found that 0.008 wt% industrial GO can assist FA to lower the consumption of cement by over 20% and improve the engineering properties by 2.6-53.6% at the same time. This research further proves that GO is promising for CWRB composites reinforcement and solid waste recycling.

Automated summary

This study utilized industrial graphene oxide (GO) and fly ash (FA) to create a high-performance, low-cost, and environmentally-friendly material for backfill. The GO-FA hybrid significantly improved the microstructural matrix of hydrated cement, leading to a significantly reinforced compressive strength of the CWRB specimens. Compared to traditional backfill materials, the addition of 0.008 wt% industrial GO assisted FA in reducing cement consumption by over 20% and improving engineering properties by 2.6-53.6% at the same time.