Value added utilization of ferronickel slags as raw materials of 4A zeolite for CO2 reduction

The scale of smelting ferronickel by RKEF (Rotary kiln—electric furnace) process is increasing these years, these untreated ferronickel slags will occupy a large area as accumulation and cause ecological damage. On the other hand, the CO2 emission and global warming are urgent problems to be solved as they have resulted in severe climate change. Carbon Capture and Storage (CCS) technology is considered as a feasible solution to the problem of excessive CO2 emissions, and the key of the CCS is the exploration for adsorbents which are low-cost, efficient and energy saving. We found that it is viable to use ferronickel slag as raw material to synthesize 4A zeolite. Further improvement for the purities of 4A zeolite was also accomplished by optimizing the synthesis conditions via single factor experiments. The as-synthesized sample was characterized in terms of structural morphology, chemical composition and surface properties. The adsorption and adsorption kinetics properties were investigated by thermal gravimetric analyzer and four models, respectively. The results indicated that 4A zeolite has a great performance in the adsorption and separation of CO2/N2 with the high value-added utilization of ferronickel slags which conducts.