In this work, primary test of ferrite formation by coprecipitation method from pure Fe(NO3)39H2O and
FeSO47H2O were evaluated at different pH and temperature by continues stirring using magnetic stirrer.
The optimized method was applied on simulated and real acid mine drainage (AMD). The impact of
simultaneous removal of metals and sulphate on the magnetic moment of ferrite sludge and addition
of ferrite or ferrite sludge seeds into real AMD samples were also investigated. The XRD results of synthesised
ferrite from pure binary salts confirmed that presence of heat and increased pH improved the
degree of crystallite of ferrite. During neutralization of AMD using sodium hydroxide, gypsum was not
precipitated in the absence of calcium hydroxide or barium ions. Consequently, the two step processes
were applied; whereby metals are removed in the first step via ferrite sludge formation using sodium
hydroxide and followed by treatment of the filtrate with barium chloride or barium hydroxide for complete
sulphate removal as barium sulphate precipitate. From the analysis results, the ferrite sludge produced
separately from sulphate showed higher magnetic moments than produced simultaneously. In the
pH range of 7–8.5, at temperature of 60 C, 93%, 12%, and 28%, and 99.6%, 57.5% and 47.5% of Fe, Mn and
Co were removed from real AMD; in the absence and presence of ferrite seeds in 20 min reaction time,
respectively. Furthermore, the rate of metal removals and magnetic moments of synthesised ferrite
sludge were increased in the presence of ferrite seeds. Generally, these results indicated that AMD could
be used as a resource for production of commercially valuable chemicals, which in turn could help to offset
the cost of treatment.