Yurchenko H. The technology of selective extraction of Nickel and its compounds from secondary raw materials

Subject of the inquiry: chemical processing of the solid-phase nickel-containing raw materials with selective extraction of nickel and its compounds for their further desoxydation. Purpose of the study: rationalization of the theoretical basis and development of the economically sound and resource saving technology for selective extraction of nickel compounds (II) from recoverable solid-phase raw materials and for their desoxydation to metal. Research methods: X-ray diffraction, X-ray phase, mass spectrometric, electron microscopical and X-ray photoelectroscopic, spectrophotometric, chromatographic, conductometric, gravimetric and titrimetric analysis. Theoretical results and application: basic kinetic properties of each stage of the developed technology have been determined; numerical representation of the selective extraction of nickel and its compounds from anodes of the spent nickel-iron accumulators combining such parameters as extraction ratio, temperature and duration of the chemical interaction has been developed; process variables of the sedimentation of nickel (II) hydroxide from nickel (II) hyxaminchloride solution with NaOH have been studied; process variables of Ni(OH)2 desoxydation with hexamethylenetetramine have been investigated. The applicability of the developed technology has been confirmed by the thermodynamic calculations. Novelty: method for selective extraction of nickel and its compounds from anodes of the spent nickel-iron accumulators using the ammonia buffer solution containing ammonium chloride has been developed; process variables of spherical nickel (II) hydroxide of beta-modification by means of its sedimentation from nickel (II) hyxaminchloride solution with NaOH have been determined; the effect of the sedimentator concentration on the fractional composition of Ni(OH)2 sediment has been established; method of thermochemical desoxydation of Ni2+to Ni0 with hexamethylenetetramine used for production of metallic nickel powder with homogeneous fractional composition and 99.9% purity has been developed. Implementation: the method developed for selective extraction of nickel and its compounds from recoverable solid-phase raw materials has been implemented at the Private Enterprise "Rika Plus" (Kharkov). The research findings are being used for the educational purposes at the National Technical University "Kharkov Polytechnic Institute" at the department of "Nonorganic, catalysis and ecological engineering chemistry" 05.17.01. Application: chemical industry.