PROCESSING OF PHOSPHOGYPSUM TO OBTAIN A CONCENTRATE OF RARE EARTH ELEMENTS ON THE EXAMPLE OF ОJSC «GOMEL CHEMICAL PLANT»
Abstract
The main objects of the investigation were lanthanum, cerium and neodymium fluorides, phosphates and hydroxides, as well as phosphogypsum.
The purpose of this work was to develop methods for purposeful synthesis of lanthanide compounds with predetermined chemical composition during phosphogypsum acid treatment on the basis of data obtained on solubility, extraction and thermodynamic characteristics of individual rare earth elements (REE) compounds.
Solubility equilibriums for LnF3 and LnPO4 in phosphoric acid at 70 °С, as well as for LnF3, LnPO4 and Ln(OH)3 in water at 25 °C and 50 °C have been studied. Solubility constants of these compounds have been determined; principles of dissolution equilibrium for the above lanthanide compounds have been established.
Chemical composition of these compounds and nature of their inclusion into phosphogypsum has been determined.
The complex of thermodynamic characteristics for processes of preparation of lanthanum, cerium, neodymium fluorides, phosphates and hydroxides from their nitrates, standard enthalpies of formation, Gibbs energies and absolute enthropies for individual compounds have been calculated.
Processes for REE compounds extraction from solutions obtained through phosphogypsum treatment by nitric acid, using organophosphorus compounds, such as tributyl phosphate, di-iso-octyl methylphosphonate, isoamyldibutylphosphine oxide, have been investigated.
The schematic process diagram for obtaining group REE concentrate containing no less than 96 ww.% of the main compound, from phosphogypsum have been produced at OJSC «Gomel Chemical Plant».
About the Authors
N. V. Zyk
EI «Belarusian National Technical University»
Belarus
Belarus
Minsk
V. O. Shunkevich
EI «Belarusian National Technical University»
Belarus
Belarus
Minsk
V. V. Zyk
EI «Belarusian National Technical University»
Belarus
Belarus
Minsk
References
1. Комплексная азотнокислотная переработка фосфатного сырья / А. Л. Гольдинов [и др.] ; ред. А. Л. Гольдинов, Б. А. Копылев. – Л. : Химия, 1982. – 207 с.
2. Ферсман, А. Е. Апатит, его месторождения, геохимия, запасы и экономика / А. Е. Ферсман // Хибинские апатиты. – Л. : ОГИЗ, 1991. – Т. 3.
3. Характер включения РЗЭ цериевой подгруппы в структуре кристаллогидратов сульфата кальция / Н. Н. Бу- шуев [и др.] // Журн. прикл. химии. – 1988. – Т. 61, № 10. – С. 2153–2158.
4. Мелихов, И. В. Захват примеси при росте кристаллов из раствора / И. В. Мелихов // Рост кристаллов. – М., 1998. – Т. IX. – С. 302.
Review
For citations:
Zyk N.V., Shunkevich V.O., Zyk V.V. PROCESSING OF PHOSPHOGYPSUM TO OBTAIN A CONCENTRATE OF RARE EARTH ELEMENTS ON THE EXAMPLE OF ОJSC «GOMEL CHEMICAL PLANT». Mechanization and Electrification of Agriculture. 2022;(55):214-219. (In Russ.)
Views: 238
Email this article 