using recycled magnetite from concrete waste as a pigment for flexographic ink

Magnetite can be used as an additive and colorant for ink preparation. this material can be produced using several methods; however, its recycling is a safer and more environmentally friendly approach due to resource scarcity. waste management and recycling are now major concerns due to the rise in industrial production. the current work offered a viable method for recycling magnetite particles, considered residues of micro-silica preparation in concrete production factories. the resulting magnetite was utilized as a pigment in flexographic water-based ink as a replacement for the virgin pigments in an ink formulation. x-ray diffraction (xrd) patterns, scanning electron microscopy (sem), energy dispersive spectroscopy (eds), particle size analysis (psa), rheology measurement, and color characteristics were used to characterize the ink and the recovered pigment. the results showed that the recycled magnetite has a larger particle size than the original pigment. in addition, the blackness and printability of the prepared ink are superior to the original black ink. results showed a small reduction in optical density (o.d.) of the ink made from recycled pigment in comparison with virgin ink. despite these lower o.d. values, it is still suitable in the appropriate range for use in applications without changes in viscosity parameters.