FIELD: processing and dressing of iron ore. SUBSTANCE: ferromagnetic content is determined by measuring magnetic susceptibility of solid phase of ore slurry after the first stage of crushing iron ore and concentrate slurry produced in the last stage of the ore dressing. Magnetic measurement is performed by imposing static and alternating mutually perpendicular magnetic fields. Iron content in concentrate is calculated according to formula: F = A•K2p/K1p+B•K4k/K3k + C where K1p is magnetic susceptibility of ore slurry measured upon imposing alternating magnetic field, K2p the same measured upon imposing static (stabilized) and alternating mutually perpendicular magnetic fields, K3p magnetic susceptibility of concentrate slurry measured upon imposing alternating magnetic field, K4p the same measured after completing action of static stabilized magnetic field, A, B, C are constant coefficients determined from calibration graphs made for reference samples. Device has two sampling arrangements with inlet and outlet valves, primary transformer with measuring and magnetizing bobbins disposed on the sampling arrangements, and also control unit including coordination panels of sampling arrangements and information-control computing assembly. EFFECT: increased accuracy of determination. 2 cl, 11 dwg
