Bis­muth (Bi) is a chem­i­cal ele­ment belong­ing to group V of Mendeleev’s peri­od­ic table. Its unique phys­i­cal and chem­i­cal prop­er­ties, such as low ther­mal con­duc­tiv­i­ty, high dia­mag­net­ism, abil­i­ty to form low-melt­ing alloys, and envi­ron­men­tal safe­ty, make this met­al extreme­ly valu­able for indus­try. In nature, bis­muth occurs both as a native met­al and in min­er­als rich in sul­phur, sele­ni­um, tel­luri­um and oth­er ele­ments.

Bis­muth ores are includ­ed in the list of min­er­als of nation­al impor­tance approved by Res­o­lu­tion of the Cab­i­net of Min­is­ters of Ukraine No. 827 of 12 Decem­ber 1994.

Bismuth minerals and its ores

Among bis­muth min­er­als, native bis­muth and com­pounds such as bis­muthi­nite (Bi₂S), koza­lite (Pb₂Bi₂S₅), aiki­nite (CuPb­BiS₃), tetradymite (Bi₂Te₂S), tel­luro­bis­muthite (Bi₂Te₃) and bis­muthite (Bi₂O₃). In the hyper­ge­n­e­sis zone, these min­er­als often trans­form into hydrox­ides and car­bon­ates, which form sur­face oxide deposits.

The abun­dance of bis­muth in the Earth­’s crust is only 1.7×10⁻⁵%, mak­ing it a rel­a­tive­ly rare ele­ment. Most bis­muth is con­cen­trat­ed in acidic igneous rocks and in areas of active min­er­al­i­sa­tion.

Types of bismuth deposits

Bis­muth deposits are divid­ed into two large groups: endoge­nous and exoge­nous. Endoge­nous deposits, asso­ci­at­ed with mag­mat­ic and post-mag­mat­ic process­es, are the most com­mon and con­tain bis­muth in com­plex ores.

Endoge­nous deposits
These deposits are formed under high-tem­per­a­ture con­di­tions and are usu­al­ly asso­ci­at­ed with gran­i­toid com­plex­es. They con­tain bis­muth in the form of their own min­er­als or iso­mor­phic impu­ri­ties in ores of oth­er met­als. The main types of endoge­nous deposits include:

• Grazen-tung­sten deposits (Kaza­khstan, Chi­na).
• Skarn deposits (Far East of Rus­sia, Korea, USA).
• Tin-sul­phide deposits (Bolivia).
• Cop­per-gold deposits (Aus­tralia).

Bismuth deposits

Most of the world’s bis­muth reserves are con­cen­trat­ed in com­plex deposits of oth­er met­als, such as lead, zinc, cop­per, molyb­de­num, gold. In such ores, bis­muth is a com­pan­ion com­po­nent and may be present as microin­clu­sions of its own min­er­als or as iso­mor­phic impu­ri­ties.

For exam­ple, in the poly­metal­lic ores of Peru (Ser­ro de Pas­co deposit), bis­muth accounts for a sig­nif­i­cant part of the by-prod­uct. A sim­i­lar sit­u­a­tion is observed in the molyb­de­num-tung­sten deposits of Kaza­khstan, tin ores of Bolivia and cop­per-gold deposits of Aus­tralia.

Ukraine does not have its own indus­tri­al bis­muth deposits. How­ev­er, bis­muth min­er­al­i­sa­tion has been iden­ti­fied here in the form of min­er­als (native bis­muth, bis­muthi­nite, bis­muth tel­lurides, mal­donite) in gold deposits of the Ukrain­ian Shield (US), where bis­muth may be mined as a by-prod­uct in the future; in rare met­al occur­rences in the Mid­dle Bug Riv­er region (Savranske and Stanku­vatsk) and Volyn (Pru­tivske), where signs of arsenic-bis­muth and nick­el-cobalt-bis­muth min­er­al­i­sa­tion are not­ed; molyb­de­num occur­rences in the Sushchano-Perzhan­s­ka zone (Ver­bynske, Ustynivske), as well as in ore occur­rences in the East­ern Azov region (Kychik­su). These occur­rences are con­sid­ered promis­ing for the extrac­tion of bis­muth as a com­pan­ion com­po­nent.

An ele­vat­ed bis­muth con­tent (up to 0.001%) has been estab­lished in quartz veins on the south­ern edge of the Alferivs­ka syn­cline (Verkhivt­se­va ZKS), as well as in sec­ondary quartzites behind ultra­ba­sic rocks with sul­phide cobalt — nick­el min­er­al­i­sa­tion of the cen­tral part of the syn­cline (up to 0.02%), where bis­muth has also been found.

Uses of bismuth

Bis­muth is a unique met­al that, thanks to its phys­i­cal and chem­i­cal prop­er­ties, is wide­ly used in var­i­ous indus­tries. Its envi­ron­men­tal safe­ty, low tox­i­c­i­ty and abil­i­ty to form low-melt­ing alloys make it an impor­tant ele­ment in mod­ern pro­duc­tion.

Met­al­lur­gy
One of the main areas of appli­ca­tion for bis­muth is met­al­lur­gy. It is used to make low-melt­ing alloys with met­als such as lead, tin and cad­mi­um. These alloys are used in the man­u­fac­ture of tem­per­a­ture fus­es, elec­tri­cal fus­es, ther­mome­ters and oth­er prod­ucts that require sen­si­tiv­i­ty to tem­per­a­ture changes. Bis­muth is also used in the man­u­fac­ture of moulds and dies, which allows the cre­ation of com­plex shapes.

Phar­ma­ceu­ti­cals
Bis­muth is an impor­tant com­po­nent in phar­ma­ceu­ti­cals due to its dis­in­fec­tant, anti-inflam­ma­to­ry and dry­ing prop­er­ties. Bis­muth com­pounds are includ­ed in med­i­cines used to treat pep­tic ulcers, gas­tri­tis, and stom­ach and intesti­nal infec­tions. The most well-known drug is bis­muth sub­c­i­trate, which is effec­tive in com­bat­ing the bac­teri­um Heli­cobac­ter pylori.

Chem­i­cal indus­try
In the chem­i­cal indus­try, bis­muth is used as a cat­a­lyst in var­i­ous process­es. In par­tic­u­lar, it is used in the pro­duc­tion of syn­thet­ic fibres, plas­tics and oth­er poly­mer­ic mate­ri­als. Its cat­alyt­ic prop­er­ties increase the effi­cien­cy and speed of chem­i­cal reac­tions.

Elec­tron­ics
In the field of elec­tron­ics, bis­muth is used in the man­u­fac­ture of semi­con­duc­tor mate­ri­als. Its com­pounds are used in ther­mo­elec­tric gen­er­a­tors that con­vert heat into elec­tri­cal ener­gy. This is par­tic­u­lar­ly impor­tant in sit­u­a­tions where autonomous pow­er sup­ply is required, such as in space­craft.

Nuclear ener­gy
Bis­muth is used as a liq­uid coolant and cool­ing ele­ment in nuclear reac­tors. Due to its high tem­per­a­ture char­ac­ter­is­tics and chem­i­cal inert­ness, it is ide­al for this pur­pose.

Glass and ceram­ics indus­try
The met­al is used to increase the refrac­tive index of glass. This allows the cre­ation of high-qual­i­ty optics and enam­els that are high­ly resis­tant to tem­per­a­ture effects. Bis­muth is also added to low-melt­ing enam­els used in the pro­duc­tion of dec­o­ra­tive and tech­ni­cal ceram­ics.

Oth­er indus­tries
Bis­muth is used in the man­u­fac­ture of heat-sen­si­tive sen­sors, as well as in the pro­duc­tion of machine gun and hunt­ing ammu­ni­tion as an envi­ron­men­tal­ly friend­ly alter­na­tive to lead. The met­al is also used as a com­po­nent in cos­met­ics, for exam­ple, to cre­ate pearles­cent effects.

Thus, thanks to its prop­er­ties, bis­muth is an extreme­ly valu­able met­al for mod­ern indus­try. Its use cov­ers a wide range of indus­tries, from med­i­cine to high-tech man­u­fac­tur­ing. The demand for bis­muth con­tin­ues to grow, which is explained by its unique char­ac­ter­is­tics and envi­ron­men­tal advan­tages. Although Ukraine does not have its own deposits, the prospects for bis­muth min­ing as a by-prod­uct could become an impor­tant direc­tion for the devel­op­ment of the domes­tic resource base.