Plat­inum is more expen­sive than gold and is becom­ing more and more pop­u­lar for mak­ing jew­el­ry. It is resis­tant to high tem­per­a­tures, is not prone to cor­ro­sion and is exposed to only a few chem­i­cals. There­fore, it is often used for lab­o­ra­to­ry equip­ment.

The name «plat­inum» comes from the Span­ish «plati­no» (small sil­ver). Plat­inum was first dis­cov­ered in plac­er deposits where it formed steel gray nuggets that looked like sil­ver, but behaved like gold.

Com­pared to gold and sil­ver„ plat­inum was rec­og­nized as an inde­pen­dent ele­ment quite late, in 1750, although it is known from a plat­inum prod­uct from 700 BC. Pal­la­di­um and rhodi­um as part of South Amer­i­can plat­inum was dis­cov­ered by V. Wol­las­ton in 1803, and in 1804. S. Ten­nant obtained irid­i­um and osmi­um as part of the residue after dis­solv­ing crude plat­inum.

Met­als of the plat­inum group are includ­ed in the list of min­er­als of nation­al impor­tance, approved by by the res­o­lu­tion of the Cab­i­net of Min­is­ters of Ukraine dat­ed Decem­ber 12, 1994 № 827, as ores of pre­cious met­als.

Plat­inum group met­als (PGE) include plat­inum (Pt), pal­la­di­um (Pd), rhodi­um (Rh), ruthe­ni­um (Ru), irid­i­um (Ir) and osmi­um (Os), which have sim­i­lar chem­i­cal prop­er­ties and occur togeth­er in nature.

Plat­inum and pal­la­di­um, the con­cen­tra­tion of which in the earth­’s crust is about 5 ppb, are as scarce as gold„ and oth­er PGEs are even more scarce.

Plat­inum occurs main­ly in the form of native plat­inum (usu­al­ly small par­ti­cles, but some­times nuggets in plac­ers), as an alloy with oth­er pre­cious met­als, and as impu­ri­ties in sul­fides or chromite. There are also plat­inum min­er­als – bre­gite (Pt,Pd,Ni)S, sperilite PtAs₂, moncheite (Pt, Pd)(Te₂,Bi), lau­rite RuS₂.

Except for gold and rhe­ni­um, plati­noids are the rarest sta­ble ele­ments in the Earth­’s crust. Irid­i­um, rhe­ni­um, rhodi­um and ruthe­ni­um are the rarest (exact order is var­i­ous­ly giv­en in the lit­er­a­ture). The annu­al pro­duc­tion of plat­inum and pal­la­di­um is about 200 tons. Typ­i­cal ore con­tents range from 3 to 10 g/t, even low­er, if nick­el or chromi­um can be mined at the same time.

Plat­inum — sil­ver-white met­al with a metal­lic lus­ter that does not fade in air. It is very hard, forg­ing, plas­tic and has a high melt­ing point (1768 °C). Plat­inum is well machined, is a good con­duc­tor of heat and elec­tric cur­rent. The met­al is chem­i­cal­ly resis­tant: it does not oxi­dize in air, does not react with most acids (except roy­al vod­ka), is resis­tant to the influ­ence of aggres­sive envi­ron­ments. Due to these prop­er­ties, plat­inum is wide­ly used in the chem­i­cal indus­try and elec­tron­ics.

Pal­a­di­um — is a sil­ver-white, soft and plas­tic met­al with high chem­i­cal activ­i­ty at high tem­per­a­tures. Easy to roll and stamp. It has a melt­ing point of 1555 °C. A good con­duc­tor of heat and elec­tric­i­ty. Pal­la­di­um is chem­i­cal­ly sta­ble under nor­mal con­di­tions, but is capa­ble of absorb­ing large vol­umes of hydro­gen (up to 900 vol­umes per 1 vol­ume of met­al), a unique prop­er­ty. Slow­ly dis­solves in hot acids, does not oxi­dize in air.

Irid­i­um — is a shiny sil­ver-white met­al, one of the hard­est and most resis­tant to cor­ro­sion. Very refrac­to­ry (2446 °C), has high den­si­ty and hard­ness. Although dif­fi­cult to process due to brit­tle­ness, able to with­stand extreme tem­per­a­tures with­out defor­ma­tion. Irid­i­um is chem­i­cal­ly inert: it does not oxi­dize even when heat­ed, it is resis­tant to acids and alka­lis. It is often used in alloys for coat­ings oper­at­ing in aggres­sive con­di­tions.

Osmi­um — is a bluish-sil­ver met­al with a char­ac­ter­is­tic sheen hav­ing the high­est den­si­ty of all ele­ments (about 22.6 g/cm³). It is very hard and brit­tle, has a high melt­ing point (3033 °C). Osmi­um is poor­ly machined and is a good con­duc­tor. It forms tox­ic osmi­um tetrox­ide (OsO₄) in the air, so it needs care­ful han­dling. Extreme­ly resis­tant to the action of acids, does not dis­solve in roy­al vod­ka. Occurs in alloys with plati­noids.

Rhodi­um — sil­ver-white met­al with a mir­ror shine, very hard but less mal­leable than plat­inum. Melt­ing point — 1964 °C. It has high resis­tance to oxi­da­tion, does not fade in air. Rhodi­um is chem­i­cal­ly inert, does not dis­solve in acids, except for hot roy­al vod­ka. He is a good con­duc­tor of elec­tric­i­ty. Due to its shine and sta­bil­i­ty, it is often used for dec­o­ra­tive and pro­tec­tive coat­ings, as well as as a cat­a­lyst.

Ruthe­ni­um — is a sil­ver-gray sol­id met­al with a hexag­o­nal crys­tal lat­tice. It has a high melt­ing point (2334 °C) and hard­ness. Frag­ile at room tem­per­a­ture, poor­ly machin­able. Ruthe­ni­um is chem­i­cal­ly sta­ble: it does not oxi­dize in air, does not react with acids under nor­mal con­di­tions. Like oth­er PGEs, it is an effec­tive cat­a­lyst, often used in elec­tron­ics and chem­i­cal syn­the­sis.

Plati­noid deposits are divid­ed into indige­nous (endoge­nous) and plac­er (exoge­nous), and accord­ing to the com­po­si­tion of – into actu­al plati­noid (plat­inum met­al) and com­plex, which con­tain PGE as accom­pa­ny­ing com­po­nents.

Root deposits are most often rep­re­sent­ed by bod­ies of plat­inum-bear­ing sul­fide and chromi­um ores of mas­sive or inter­spersed tex­ture genet­i­cal­ly relat­ed to intru­sions of basic and ultra­maf­ic rocks. Such deposits belong to the mag­mat­ic type.

The lead­ing place among the com­plex sources of PGE is occu­pied by cop­per-nick­el sul­fide ores, in which plat­inum and pal­la­di­um are con­cen­trat­ed in pyrrhotite, chal­copy­rite, pent­landite, cuban­ite and min­er­als of plat­inum ele­ments – inter­metal­lic com­pounds, sol­id solu­tions, arsenides and sul­fides Pd and Pt.

Among the most famous:

• dif­fer­en­ti­at­ed intru­sions of gabrodolerites (Insiza, South Africa);
• strat­i­form intru­sions of gabronorites with hyper­b­a­sites (Bushveld com­plex, South Africa);
• lay­ered arrays of norites and gra­n­odi­or­ites (Sad­bury, Cana­da).

Less impor­tant are chromi­um ores (Bushveld, Still­wa­ter, USA), cop­per and black shale, cop­per, molyb­de­num and tin-por­phyry deposits, indi­vid­ual gold and gold poly­metal­lic objects, as well as ocean­ic iron-man­ganese nod­ules and crusts.

Splash deposits are formed as a result of the destruc­tion of plat­inum-bear­ing ultra­maf­ic mas­sifs. Meso-Ceno­zoic plac­ers of plat­inum and irid­i­um osmis pre­dom­i­nate. Pro­duc­tive lay­ers reach sev­er­al meters in thick­ness, and the width is — hun­dred meters.

About 90% of the world’s MPG reserves are con­cen­trat­ed in actu­al plat­inum late-mag­mat­ic deposits of dif­fer­en­ti­at­ed hyper­b­a­site com­plex­es. The most pro­duc­tive are chromite-con­tain­ing «reefs» of norites, anorthosites and pyrox­en­ites, in par­tic­u­lar Meren­sky and UG‑2 (Bushveld, South Africa) –, which account for ~77.5% of world reserves. Anoth­er 11% is asso­ci­at­ed with sul­fide-arsenide lay­ers of hyper­b­a­site mas­sifs (Plet­rif, Veli­ka Dyka, Lac-De-Ile, Still­wa­ter, Fedoro­vo-Panske), and less than 11% – with com­plex deposits of cop­per-nick­el ores (Noril­sk, Sed­bury) and oth­er types of cop­per and cop­per-vana­di­um ores. Plac­ers make up about 0.2% of reserves (Koryakia, Urals, Colom­bia).

Recent­ly, atten­tion has been drawn to uncon­ven­tion­al reser­voir hydrother­mal deposits in black-shale stra­ta (Kare­lia, Sun­lin), which with a low MPG con­tent are char­ac­ter­ized by large sizes and accom­pa­ny­ing com­po­nents (Ni, Au, Ag, Mo). The increased con­tent of plat­inum met­als is also found in ores of car­bon­atite, skarn, por­phyry, pyrite, strat­i­form deposits and in weath­er­ing crusts.

Research on plat­inum bear­ing in Ukraine began in 1951, when N.A. Singer and EA. Sudzilovs­ka found an increased plat­inum con­tent (0.1–0.2 g/t) in hyper­b­a­sites of. Obitochnaya (West­ern Azov region). In 1954, S.M. Tsym­bal and Yu.A. Polka­nov found native plat­inum in zir­co­ni­um-ilmenite plac­ers of the Dnipro-Donet­sk depres­sion. The first gen­er­al­iz­ing works appeared in the 1970’s (I.K. Latysh, A.B. Fomin, V.A. Stulchikov), and lat­er plat­inum bear­ing was stud­ied by numer­ous Ukrain­ian geol­o­gists. In 1989–2000, tar­get­ed pro­grams were car­ried out («Assess­ment of plat­inum bear­ing…», «Plati­noids of Ukraine», «Plat­inum of Ukraine»), and in 2004, the mate­ri­als were sum­ma­rized at a meet­ing of the Inter­de­part­men­tal Com­mis­sion on the Geol­o­gy of Ore Deposits.

In Ukraine, there are cur­rent­ly no indus­tri­al deposits of plati­noids, and the coun­try’s needs are cov­ered by imports. How­ev­er, sev­er­al promis­ing objects have been iden­ti­fied:

• mafite-ultra­mafite com­plex­es of the Pre­cam­bri­an Ukrain­ian shield (Volyn, Dni­ester-Buzkyi, Seredno­pryd­niprovskyi, Prya­zovskyi megablocks);
• rife traps of Volyn with the poten­tial of com­plex Cu-Au-Ag-Pt min­er­al­iza­tion;
• iron ore for­ma­tions of Kryvbas, in which local con­cen­tra­tions of plati­noids were not­ed.

Dif­fer­en­ti­at­ed intru­sions of the peri­dotite-pyrox­en­ite-gabronorite for­ma­tion of the Bukin­sky, Pru­tiv, and Kamen­sky com­plex­es are promis­ing in the Volyn megablock, where con­cen­tra­tions of Pt up to 4.9 g/t are record­ed in the zones of sul­fide min­er­al­iza­tion and meta­so­mat­ic changes. In the Dni­ester-Buz­ka megablock the increased con­tent of plati­noids is con­fined to hyper­b­a­site intru­sions, in par­tic­u­lar chromite ores of the Kap­i­taniv and Lypovenkiv mas­sifs rich in lau­rite, irar­site, native plat­inum and oth­er min­er­als.

Seredno­pryd­niprovskyi megablock con­tains numer­ous small man­i­fes­ta­tions of MPG, includ­ing in ultra­b­a­sites of the Alexan­der com­plex (Os up to 4 g/t) and gabroids of the Sofia intru­sion (Os up to 9.8 g/t). In the Azov megablock increased Pt and Pd con­tents are record­ed in hyper­b­a­sites of Obitochna riv­er, Sorokin­sky zone and Oktyabrsky mas­sif.

Rifei lad­ders of Volyn (Zhyrychi, Rafalivs­ka areas) are promis­ing for com­plex ores with cuprum, gold, sil­ver and PGE, with fore­cast reserves of hun­dreds of mil­lions of tons. In the Kryvyi Rih basin, plati­noids were found in sul­fidized meta­grav­elites, mar­tite and sul­fide con­cen­trates, as well as in the cop­per-molyb­de­num-rare met­al for­ma­tion of the Kara­chu­niv-Lozo­vac zone and pyrite-poly­metal­lic ores.

Future research may focus on rock-type hyper­b­a­sites of the Carpathi­ans, gold-bear­ing bir­chite-leaf-ven­ite meta­so­matites, ore-bear­ing skarns of the Mid­dle Pobuzhzhia, coal-bear­ing and red-col­ored deposits of Don­bas, weath­er­ing crusts of ultra­b­a­sites of the USH and allu­vial plac­ers where local impu­ri­ties of plat­inum and pal­la­di­um are record­ed.

Plat­inum — is a uni­ver­sal met­al wide­ly used in the chem­i­cal indus­try for the man­u­fac­ture of equip­ment that works with aggres­sive envi­ron­ments and at high tem­per­a­tures, as well as chem­i­cal dish­es, cat­a­lysts in oil refin­ing, elec­trode coat­ing, resis­tance ther­mome­ters and ther­mo­cou­ples (for mea­sur­ing tem­per­a­tures over 1000 °C), fil­ters for clean­ing gas­es, fer­ro­mag­net­ic alloys. It finds appli­ca­tions in the glass indus­try, jew­el­ry, com­put­er tech­nol­o­gy, and in the man­u­fac­ture of per­ma­nent mag­nets.

Pal­a­di­um is obtained from plat­inum met­al con­cen­trates. It is used in jew­el­ry, chem­i­cal equip­ment, den­tistry, as a cat­a­lyst, as well as in elec­tri­cal engi­neer­ing.

Osmi­um is iso­lat­ed from plat­inum con­cen­trates in the form of a volatile com­pound OsO₄ with sub­se­quent reduc­tion to pow­der. It is used as a cat­a­lyst (ammo­nia syn­the­sis, hydra­tion of organ­ic com­pounds) and an alloy­ing addi­tive to ultra-strong alloys.

Irid­i­um is extract­ed from plat­inum and gold plac­ers, MPG con­cen­trates and cop­per-nick­el ores. Irid­i­um alloys, espe­cial­ly with plat­inum, are used for chem­i­cal dish­es, jew­el­ry, sur­gi­cal instru­ments, insol­u­ble anodes and pre­ci­sion instru­ments (in par­tic­u­lar, met­ric sys­tem stan­dards).

Ruthe­ni­um is obtained from plat­inum ores by reduc­ing RuO₄ with hydro­gen. It is used as a cat­a­lyst and is also added to plat­inum and pal­la­di­um alloys to increase strength. Plati­noruthe­ni­um alloys are used in the pro­duc­tion of elec­tri­cal con­tacts and parts with high cor­ro­sion resis­tance.

Rhodi­um is extract­ed from MPG con­cen­trates. Its alloys are used in the man­u­fac­ture of elec­trolyt­ic coat­ings, ther­mo­cou­ples, elec­tro­con­tacts and as cat­a­lysts for the syn­the­sis of organ­ic and inor­gan­ic com­pounds.

Plat­inum ores — are nat­ur­al min­er­al for­ma­tions with the con­tent of plat­inum met­als in con­cen­tra­tions suf­fi­cient for indus­tri­al devel­op­ment. The MPG con­tent in native plat­inum deposits is 2–5 g/t or more, in com­plex deposits — from tenths to hun­dreds of g/t, and in plac­ers — from tens of mil­ligrams to hun­dreds of grams per cubic meter.

Pro­duc­tion is car­ried out by open (spills, drain­ing, hydro­mech­aniza­tion) and under­ground (indige­nous deposits) meth­ods. Enrich­ment of met­al-bear­ing sands and crushed ores makes it pos­si­ble to obtain a con­cen­trate with a plat­inum min­er­al con­tent of 80–90%, which is sub­ject­ed to refin­ing. MPG is extract­ed from com­plex sul­fide ores by flota­tion fol­lowed by pyro, hydromet­al­lur­gi­cal, elec­tro­chem­i­cal and chem­i­cal treat­ment. Pure plat­inum is obtained by reduc­ing plat­inum con­cen­trates with hydro­gen at high tem­per­a­ture.

Met­als of the plat­inum group — are unique in phys­i­cal and chem­i­cal prop­er­ties, extreme­ly rare and strate­gi­cal­ly impor­tant for indus­try. Despite the lack of indus­tri­al deposits in Ukraine, the avail­able promis­ing facil­i­ties open up oppor­tu­ni­ties for future explo­ration and reduc­tion of depen­dence on imports.