Physico-Chemical nanomaterials science

Galvanic waste processing by energy-saving ferritization with AC-magnetic field activation
Derecha D.O.1,4, Skirta Yu.B.1,2, Samchenko D.M.3, Kochetov G.M.3
1 Institute of Magnetism, Natl. Acad. Sci. Ukraine and Min. Edu. Sci. Ukraine, Akad. Vernadsky Blvd. 36-b, Kyiv 03142, Ukraine 
E-mail: dderecha@gmail.com
2 National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute”, Peremohy Ave. 37, Kyiv 03056, Ukraine 
3 Kyiv National University of Construction and Architecture, 
Povitroflotsky Ave. 31, Kyiv 03037, Ukraine
4 Physico-technological Institute of Metals and Alloys, 
34/1 Academician Vernadsky Blvd., Kyiv 03680, Ukraine

The efficiency of the ac-magnetic field usage for resource-saving activation of the reaction mixture in the ferritization process with the extraction of heavy metals ions from galvanic waste has been confirmed. The one of the key parameters of the ferritization process - the ratio of the concentration of iron ions to the total concentration of other metal ions on the quality of galvanic waste processing has been investigated. It is determined that under the optimal processing conditions (ratio of concentrations of iron ions to other heavy metal ions 3.5 ÷ 4/1) the residual concentrations of heavy metal ions decrease to the values: Fe2+;3+ - 0,1; Ni2 + - 0.26; Cu2 + - 0.2; Zn2 + - 0.19 mg / dm3. 
It is established that the AC-magnetic field activation provides the metal ions extraction degree of 99.96%, and also has undeniable energy advantages in comparison with thermal technique: the energy consumption is reduced by more than 60%. This indicates the suitability of purified water for reuse in galvanic production due to the requirements for the heavy metal ions content. Also, the structural studies of ferritic sediments shown that samples obtained at the ratio of heavy metal ions concentrations 4/1 phases characterized by the maximum content of crystalline ferromagnetic ferrite (Ni0.53Cu0.3 Zn0.17Fe2O4) ≥ 76% were detected. 
The consumption of electricity for AC-magnetic field activation in comparison with thermal one is reduced by 60%. That makes possible to reduce the cost of this technique, and thus make it attractive for industrial applications.