The group of rare earth ele­ments includes yttri­um, scan­di­um and 15 lan­thanides with atom­ic num­bers from 57 to 71 accord­ing to the peri­od­ic sys­tem D. Mendelee­va: lan­thanum, ceri­um, praseodymi­um, neodymi­um, prome­thi­um, samar­i­um, europi­um, gadolin­i­um, ter­bium, dys­pro­sium, holmi­um, erbium, thuli­um, ytter­bium, lutetium.

There are about 70 min­er­als known in nature that con­tain rare earth ele­ments as the main com­po­nents, and more than 200 – as impu­ri­ties. Indus­tri­al­ly sig­nif­i­cant min­er­als: mon­azite, xenothym, bast­ne­site, apatite, parisite, pyrochlor, fer­gu­sonite, samarskite, flu­o­rite, gadoli­n­ite, eudi­alite, aegirine.

Rare earth ele­ments give mate­ri­als unique prop­er­ties – increased strength, heat resis­tance, opti­cal sta­bil­i­ty and effi­cien­cy under con­di­tions of extreme loads. They play an impor­tant role in the cre­ation of high-tech mate­ri­als for avi­a­tion, mil­i­tary, elec­tron­ic and oth­er indus­tries. A num­ber of promis­ing REE deposits have been iden­ti­fied in Ukraine, which are of sig­nif­i­cant inter­est for indus­try and sci­en­tif­ic research.

Geography of ore areas of rare earth elements

On the ter­ri­to­ry of Ukraine, three main areas of rare met­al min­er­al­iza­tion stand out: Pri­a­zovsky, Pryd­niprovsky and Volyn­sky.

Pri­a­zovsky dis­trict cov­ers the ter­ri­to­ries of Donet­sk and Zapor­izhzhia regions that are cur­rent­ly under occu­pa­tion. It is home to the Mazurivske deposit asso­ci­at­ed with mar­i­upo­lites and nepheline peg­matites, the Novopoltavske deposit (900 ha in area) asso­ci­at­ed with car­bon­atites, and the Azovske and Petro­vo-Hnu­tivske deposits in alka­line syen­ite.

Pryd­niprovsky dis­trict cov­ers Dnipropetro­vsk, Kirovohrad and Vin­nyt­sia regions. Maly­shevske and Vovchanske tita­ni­um-zir­co­ni­um plac­er deposits stand out in this region. The Per­vo­maiske deposit in the north­ern part of the Kryvoriz­ka struc­ture is known for sig­nif­i­cant scan­di­um min­er­al­iza­tion in aegirine. The Sabarivske deposit and the Rizhkiv man­i­fes­ta­tion, which con­tain indus­tri­al con­cen­tra­tions of neodymi­um, are locat­ed in Vin­nyt­sia.

Volyn dis­trict cov­ers the ter­ri­to­ries of Zhy­to­myr region. The Perzhanske com­plex deposit of beryl­li­um and the Yas­tru­betske flu­o­rite-yttri­um deposit con­tain­ing sig­nif­i­cant deposits of rare earth min­er­als are locat­ed here. Sig­nif­i­cant scan­di­um anom­alies are observed in plac­er tita­ni­um-zir­co­ni­um deposits of the Volyn tita­ni­um-bear­ing dis­trict.

Main deposits of rare earth elements in Ukraine

Novopoltavske deposit, locat­ed in the Zapor­izhzhia region, is an impor­tant source of apatite, rare earth met­als, ele­ments of tan­ta­lum-nio­bates and zir­co­ni­um. The main rock-form­ing min­er­als are cal­cite, dolomite, biotite, apatite and mag­netite. Ore reserves are sig­nif­i­cant, which makes this deposit promis­ing for the extrac­tion of rare earth resources.

The Mazurivske deposit on the ter­ri­to­ry of the Azov region con­tains com­plex mar­i­upo­lites with min­er­als of zir­con, pyrochlore and brito­lite. Thanks to the com­plex com­po­si­tion of the ores, it is pos­si­ble to simul­ta­ne­ous­ly obtain nio­bi­um, tan­ta­lum and alu­minum. The devel­oped tech­nolo­gies make it pos­si­ble to extract nio­bi­um as a by-prod­uct in the amount of up to 1000 tons per mil­lion tons of alu­mi­na. Rock-form­ing min­er­als of mar­i­upo­lites – nepheline, albite, aegirine, some­times micro­cline. The main acces­so­ry min­er­als of rare met­als – zir­con, pyrochlore, brito­lite. Their con­tent, espe­cial­ly zir­con, can change in a fair­ly sig­nif­i­cant inter­val. Some­times zir­con becomes a rock-form­ing min­er­al, reach­ing 2–5 %. How­ev­er, in rela­tion to Nb and TR, mar­i­upo­lites are not rich ores.

The Azovske deposit is local­ized in the periph­er­al part of the South Kalchyt­sky mas­sif. The main ore-form­ing min­er­als are – zir­con and brito­lite. Zir­con and brito­lite – are the main ore-form­ing min­er­als, but orthite and rare earth car­bon­ates are also of prac­ti­cal impor­tance. Min­er­al­iza­tion is rep­re­sent­ed by inter­spersed crys­tals and their growths.

The Yas­tru­betske deposit in Zhy­to­myr region has sim­i­lar char­ac­ter­is­tics, although the con­cen­tra­tion of rare earth ele­ments here is some­what low­er. In syen­ite, the same min­er­als of rare earths were dis­cov­ered as in the Azovske deposit (brito­lite, orthite, bast­ne­site). This makes it pos­si­ble to allow the pos­si­ble pres­ence of ores rich in rare earths in the Yas­tru­bet­sky mas­sif.

Sabarivske deposit, locat­ed in Vin­nyt­sia region, is one of the promis­ing sources of rare earth met­al ores in Ukraine. The rare earth oxide (TR) con­tent in some sam­ples reach­es 6.44%, which indi­cates a high poten­tial for indus­tri­al devel­op­ment. The deposit is eval­u­at­ed accord­ing to the cat­e­go­ry of reserves С₂ and can pro­vide sig­nif­i­cant vol­umes of strate­gi­cal­ly impor­tant mate­ri­als.

Zhov­torichenske deposit in Dnipropetro­vsk region, since the end of the 19th cen­tu­ry, this deposit was exploit­ed as iron, and from 1951 to 1989 – as ura­ni­um deposit. Scan­di­um ores were dis­cov­ered here in 1976. They are rep­re­sent­ed by two vari­eties: ura­ni­um-rare earth (mala­con-apatite) and scan­di­um-vana­di­um ores. The main con­cen­tra­tor min­er­als of scan­di­um are – aegirine (con­tent 0.08–0.10%) and alka­line amphi­boles (up to 0.10%).

Per­vo­maiske deposit iron ores, locat­ed in the Kryvoriz­ka struc­ture, has a high con­cen­tra­tion of scan­di­um in aegirine.

Min­er­als con­tain­ing scan­di­um as an iso­mor­phic admix­ture were also found in Trostyan­it­skyi, Stremy­horod­skyi and Torchyn­skyi tita­ni­um-zir­co­ni­um deposits in Zhy­to­myr region, which allows to ensure Ukraine’s needs in scan­dia and access to for­eign mar­kets. In par­tic­u­lar, in the Trostyan­it­sky deposit, the con­tent of scan­di­um oxide in ilmenite con­cen­trate reach­es about 100 g/t.

It is impor­tant to note that data on reserves of rare earth deposits of Ukraine are con­fi­den­tial infor­ma­tion. Their dis­clo­sure is reg­u­lat­ed by leg­is­la­tion due to the strate­gic impor­tance of these resources for nation­al secu­ri­ty and the econ­o­my.

Use of rare earth elements

Rare earth ele­ments give mate­ri­als unique prop­er­ties – strength, heat resis­tance, opti­cal sta­bil­i­ty and increased effi­cien­cy when work­ing in extreme con­di­tions. Glass enriched with rare earth impu­ri­ties is active­ly used in mil­i­tary equip­ment, in par­tic­u­lar for opti­cal devices, armored pro­tec­tive glass and night vision sys­tems. Sights, ther­mal imagers and binoc­u­lars use lens­es and fil­ters with admix­tures of ele­ments such as praseodymi­um and europi­um, which pro­vide improved vis­i­bil­i­ty in low light and pro­tec­tion against glare.

Neodymi­um glass is used to cre­ate high-qual­i­ty laser sys­tems. Lasers serve as impor­tant com­po­nents of guid­ance sys­tems, rangefind­ers and high-pre­ci­sion weapons. Luminophores with thuli­um and europi­um increase the qual­i­ty of night vision devices, mak­ing the image clear­er and more con­trast­ing. Pro­tec­tive armored glass for mil­i­tary vehi­cles, air­craft and heli­copters is pro­duced with the addi­tion of ceri­um and lan­thanum. This pro­vides not only increased strength and impact resis­tance, but also pro­tec­tion against blast waves.

Thanks to the use of scan­di­um in alu­minum alloys, ultra-light but very strong struc­tures for avi­a­tion equip­ment are cre­at­ed, which allows to reduce weight and increase resis­tance to mechan­i­cal loads and high tem­per­a­tures. In addi­tion, mil­i­tary elec­tron­ic sys­tems, such as nav­i­ga­tion and radar devices, use heat-resis­tant glass that con­tains gadolin­i­um and dys­pro­sium, which increas­es the sta­bil­i­ty of devices in dif­fi­cult con­di­tions, in par­tic­u­lar at sig­nif­i­cant tem­per­a­ture changes.

Neodymi­um is used for the pro­duc­tion of pow­er­ful per­ma­nent mag­nets used in elec­tric motors, wind tur­bine gen­er­a­tors and house­hold appli­ances. These mag­nets are impor­tant for mod­ern ener­gy and elec­tron­ics. Rare earth ele­ments such as gadolin­i­um are also used in nuclear reac­tors as neu­tron absorbers, ensur­ing the safe and sta­ble oper­a­tion of nuclear pow­er plants.

Prospects for the development of rare earth metals in Ukraine

The devel­op­ment of rare earth met­al deposits in Ukraine is asso­ci­at­ed with a num­ber of impor­tant tech­ni­cal, eco­nom­ic and envi­ron­men­tal chal­lenges that must be over­come to ensure effi­cient and safe min­ing.
Main com­plex­i­ties include the fol­low­ing aspects:

• It is nec­es­sary to con­duct detailed geo­log­i­cal stud­ies to con­firm the vol­ume and qual­i­ty of ores, because geo­log­i­cal explo­ration in Ukraine has been on hold since the 90s of the last cen­tu­ry. In addi­tion, the data of the Sovi­et years often need clar­i­fi­ca­tion, name­ly ver­i­fi­ca­tion drilling, eco­nom­ic reassess­ment or recal­cu­la­tion of reserves accord­ing to inter­na­tion­al clas­si­fi­ca­tions. For this, the con­struc­tion of 3D mod­els using mod­ern soft­ware is used.
• Extrac­tion of rare earth ele­ments from ores is car­ried out by meth­ods of hydromet­al­lur­gy, elec­trol­y­sis, met­al­lothermy, ion exchange chro­matog­ra­phy and com­bined enrich­ment (grav­i­ty, flota­tion, mag­net­ic and elec­trosep­a­ra­tion). Fur­ther pro­cess­ing of con­cen­trates includes meth­ods of crys­tal­liza­tion, pre­cip­i­ta­tion, extrac­tion, amal­ga­ma­tion.
• Many ores con­tain sev­er­al ele­ments at the same time, which requires com­plex tech­no­log­i­cal process­es to sep­a­rate them.
• Rare earth ele­ments are often in asso­ci­a­tion with radioac­tive and heavy met­als. This pos­es addi­tion­al envi­ron­men­tal chal­lenges dur­ing their extrac­tion and pro­cess­ing. How­ev­er, sub­ject to com­pli­ance with all legal require­ments and inter­na­tion­al stan­dards, the extrac­tion of rare earth ele­ments is pos­si­ble and can be safe for the envi­ron­ment and the pop­u­la­tion.
• Sig­nif­i­cant cap­i­tal invest­ments and mul­ti-year invest­ments are nec­es­sary to start full-fledged min­ing. Poten­tial investors should be ready for a long pay­back peri­od.

There­fore, rare earth ele­ments are strate­gi­cal­ly impor­tant for the devel­op­ment of indus­try and the econ­o­my of Ukraine. Sig­nif­i­cant deposits locat­ed in dif­fer­ent regions of the coun­try have great poten­tial for extrac­tion. Fur­ther sci­en­tif­ic research and imple­men­ta­tion of mod­ern min­ing tech­nolo­gies will allow effec­tive use of these resources to ensure nation­al secu­ri­ty and eco­nom­ic devel­op­ment.