Study of influence of initial concentration of heavy metal ions on the quality of fertization processing of electroplating sludge

Abstract

Influence of the key parameter for the ferritization process - initial total concentration of heavy metal ions (СƩ) on the quality of galvanic sludge processing has been experimentally studied. It was determined, that at СƩ = 5.33 g/dm3 and electromagnetic pulse activation of the ferritization process, the lowest values ​​of residual concentrations of heavy metal ions in the purified solution were obtained: for iron – 0,10; nickel – 0,19; copper – 0,12; zinc – 0,10 mg/dm3. The obtained values ​​correspond to the average degree of extraction of these ions of 99,97%. The purified solution is suitable for reuse in electroplating facilities. As a result of structural studies of sediment samples, it was found that at total heavy metal concentration of 5,33 g/dm3 in the ferritization reaction mixture, regardless of the method of activating the process, phases containing crystalline ferromagnetic phases of ferrites (Ni, Cu, Zn) Fe2O4 exceeds 92%. The efficiency of resource-saving electromagnetic pulse activation of the reaction mixture in the ferritization process is confirmed. Using this method of activation, energy consumption is reduced by 1,5 times compared to thermal one. The proposed resource-saving ferritization technology prevents environmental pollution, ensures the rational use of raw materials and energy, as well as allows to obtain marketable products from industrial waste.