Magnetic composites have been synthesized in an inert medium inside the temperature vary T = 500–1000 °C by one-stage pyrolysis of microcrystalline flax shive cellulose modified by citric acid (MCCA) and homogeneously impregnated with Fe(NO3)3. Catalytic graphitization was studied by the thermogravimetric evaluation technique. The crystal construction, pore improvement, morphological construction and floor chemistry of carbon composites have been characterised by the N2 adsorption-desorption, XRD, SEM and FTIR strategies. The onset temperature of MCCA graphitization was discovered to be equal to 600 °C. The magnetic carbon supplies have been examined as adsorbents for removing of anionic methyl orange (MO) and cationic methylene blue (MB) dyes. The very best equilibrium adsorption capability in MB and MO was discovered within the magnetic composites synthesized at 700 and 800 °C.