Geochemical Behavior of Ferric Hydroxide Nanodispersion Under the Influence of Weak Magnetic Fields

The change of geochemical properties of ferric hydroxide nanoparticles under the influence of a weak magnetic field was investigated. Ferric hydroxide nanoparticles formed as a result of the interaction of iron-containing minerals with natural aqueous solutions are of importance for geochemical processes, especially hypergenesis, sedimentation, and soil formation. The hydrolysis of ferric chloride in hot water (t = 70-75°С) was used to obtain ferric hydroxide nanoparticles under laboratory conditions. The nanodispersion (colloidal solution) was exposed to a weak pulsed magnetic field. The spectrophotometric properties of the colloidal solution of ferric hydroxide were determined using an SF-46 spectrophotometer in the wavelength range of 320-610 nm. The size of colloidal particles was calculated by a method based on the theory of Rayleigh light scattering. The size of colloidal particles depended on the exposure duration of a pulsed magnetic field on the colloidal solution. The size of colloidal particles was due to a change in the magnitude of the diffuse ionic atmosphere under the influence of a pulsed magnetic field. The kinetic stability of the colloidal solution was evaluated by the coagulation threshold, which was determined visually by the appearance of the turbidity of ferric hydroxide colloid when adding NaCl solution. The kinetic stability of a colloidal system was determined by the size of colloidal particles. These results can be used to better understand certain hypergenesis, sedimentation, and soil formation processes.