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Studies On The Phase Equilibrium Of Me~(2+)-NH4~+-SO4~(2-)-H2O System And The Preparation Of Mn-Zn Soft Magnetic Powders By Direct Method

Posted on:2006-01-10Degree:DoctorType:Dissertation
Country:ChinaCandidate:C H PengFull Text:PDF
GTID:1101360185986675Subject:Non-ferrous metallurgy
Abstract/Summary:PDF Full Text Request
In order to overcome the disadvantages of ceramics method and co-precipitation method on the preparation of Mn-Zn soft magnetic ferrite materials, we combined hydrometallurgy and inorganic chemical engineering with ferrite technology, and the direct-method on the preparation of Mn-Zn soft magnetic ferrite has been successfully developed. In this thesis, through the studies on the phase equilibrium in the ternary Me2+-NH4+-SO42--H2O systems, the basic theories being the key factors of the simultaneous deep purification process of Fe2+, Mn2+ and Zn2+ in the leached solution containing Fe2+, Mn2+, Zn2+, Pb2+, Ca2+, Mg2+ and et al were resolved. Therefore, a novel purification method of double salt precipitation method having the capacity of purification for many kinds metal ions in solution was developed. And when the double salt precipitation technology is applied in the deep purification process of direct method, the qualities of Mn-Zn soft magnetic ferrite samples can be improved greatly. After the table and bench and industry scale experimental studies, the direct method on the preparation of Mn-Zn soft magnetic ferrite has been successfully industrialized and soft magnetic powders being similar to PC30 produced by Japan TDK company can be produced by the direct method.1. Studies on solubility phase equilibrium in the ternary Me2+-NH4+-SO42--H2O systems.1) The phase equilibrium in the ternary system of Me2+-NH4+-SO42--H2O at 298 K was studied by isothermal equilibrium method and many significant experiment results were obtained. In the ternary system of Mn2+-NH4+-SO42--H2O, there were three saturation curves given by MnSO4·H2O, (NH4)2Mn(SO4)2·6H2O and (NH4)2SO4, respectively. There were two co-saturation points A having the composition of MnSO4·H2O and (NH4)2Mn(SO4)2·6H2O and B given by (NH4)2Mn(SO4)2·6H2O and (NH4)2SO4. There were three purification crystal areas given by MnSO4·H2O (NH4)2Mn(SO4)2·6H2O, and (NH4)2SO4, respectively. In the ternary system of Zn2+-NH4+-SO42--H2O, there were three saturation curves given by ZnSO4-7H2O (NH4)2Zn(SO4)2·6H2O, and (NH4)2SO4, respectively. There were two co-saturation points C having the composition of (NH4)2Zn(SO4)2·6H2O and ZnSO4·7H2O and D given by (NH4)2SO4 and (NH4)2Zn(SO4)2·6H2O, respectively. There were three purification crystal areas given by (NH4)2Zn(SO4)2·6H2O, ZnSO4·7H2O and (NH4)2SO4, respectively. In the ternary system of Fe2+-NH4+-SO42--H2O, there were three saturation curves given by (NH4)2Fe(SO4)2·6H2O, FeSO4·7H2O and (NH4)2SO4,...
Keywords/Search Tags:salt-water systems, phase equilibrium, isothermal method, Mn-Zn soft magnetic ferrite, direct-method, double salt precipitation deep purification
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