Quartzite. Prop­er­ties, gen­e­sis, dis­tri­b­u­tion, and indus­tri­al sig­nif­i­cance

Quartzites are meta­mor­phic rocks con­sist­ing of more than 70% quartz. They are formed as a result of recrys­tal­liza­tion of quartz sand­stones under the influ­ence of high tem­per­a­tures and pres­sure. In addi­tion to quartz, they con­tain impu­ri­ties of min­er­als such as feldspar, biotite, mus­covite, sil­i­man­ite, dis­thene, andalusite, mag­netite, hematite, and oth­ers. These com­po­nents affect the phys­i­cal and chem­i­cal prop­er­ties of quartzites, deter­min­ing their suit­abil­i­ty for var­i­ous indus­tries.

Quartzite is includ­ed in the list of min­er­als of nation­al impor­tance approved by Res­o­lu­tion of the Cab­i­net of Min­is­ters of Ukraine No. 827 of Decem­ber 12, 1994, as a raw mate­r­i­al for refrac­to­ries and fac­ing mate­ri­als.

Depend­ing on the com­po­si­tion of min­er­al impu­ri­ties, there are monomin­er­al quartzites, feldspar, mica, sil­li­man­ite, sericite, and oth­er vari­eties. Quartzite-like sand­stones are a tran­si­tion­al vari­ety between sand­stones and quartzites, in which some of the quartz grains retain their orig­i­nal clas­to­genic appear­ance, while oth­ers have under­gone meta­mor­phic recrys­tal­liza­tion. The cement­ing mate­r­i­al in such rocks can be rep­re­sent­ed by quartz, mica-quartz, or chlo­rite-sericite cement, which does not com­plete­ly cement the min­er­al grains, leav­ing them par­tial­ly free. Due to minor dif­fer­ences in com­po­si­tion and struc­ture, quartzites and quartzite-like sand­stones are often grouped under the gen­er­al name “quartzites.”

Genesis of quartzites

Quartzites are formed under two main geo­log­i­cal con­di­tions: region­al and con­tact meta­mor­phism. In the first case, they are formed in the deep parts of the Earth­’s crust, where sand­stones or quartz sed­i­men­ta­ry rocks are exposed to high tem­per­a­tures and pres­sures. Dur­ing recrys­tal­liza­tion, quartz grains grow togeth­er, form­ing a dense, mono­lith­ic struc­ture.

The sec­ond mech­a­nism, con­tact meta­mor­phism, occurs in areas affect­ed by mag­mat­ic intru­sions. The high tem­per­a­ture accom­pa­ny­ing the pen­e­tra­tion of mag­ma caus­es com­paction and par­tial remelt­ing of sed­i­men­ta­ry quartz rocks. Under such con­di­tions, vari­eties of quartzite con­tain­ing impu­ri­ties of feldspar and oth­er min­er­als can form.

Quartzites may con­tain var­i­ous impu­ri­ties that entered them dur­ing the for­ma­tion stage. For exam­ple, the pres­ence of hematite or mag­netite gives the rock a red­dish or brown­ish col­or, and a high con­tent of sil­li­man­ite or dis­thene indi­cates an increased lev­el of meta­mor­phism.

Industrial significance and application of quartzites

Quartzites are a ver­sa­tile min­er­al raw mate­r­i­al wide­ly used in fer­rous and non-fer­rous met­al­lur­gy, con­struc­tion, chem­i­cal, and elec­tron­ic indus­tries. They are the main raw mate­r­i­al for the pro­duc­tion of dinas refrac­to­ries, fer­roal­loys, and quartzite-clay mix­tures used for lin­ing steel cast­ing ladles.

Due to their high sil­i­ca con­tent, quartzites are used in the pro­duc­tion of crys­talline sil­i­con, which is an impor­tant com­po­nent for the elec­tron­ics indus­try. In addi­tion, they are used as flux raw mate­ri­als in met­al­lur­gy, pro­mot­ing the for­ma­tion of slags that bind unwant­ed impu­ri­ties in the smelt­ed met­al.

Dense mono­quartzites are used in the chem­i­cal indus­try, where they are used to man­u­fac­ture acid-resis­tant mate­ri­als, as well as raw mate­ri­als for sul­fu­ric acid tow­er noz­zles. Quartzites are also a raw mate­r­i­al for the pro­duc­tion of sil­i­con-con­tain­ing alloys, such as silu­min (an alloy of alu­minum and sil­i­con) and sil­i­con car­bide, which is used in the abra­sive and ceram­ic indus­tries.

In the con­struc­tion indus­try, quartzite is used in the form of wall, fac­ing, and bro­ken stone, as well as a raw mate­r­i­al for the pro­duc­tion of spe­cial crushed stone, rub­ble, and dec­o­ra­tive mate­ri­als.

Quartzite deposits in Ukraine

Ukraine is one of the world’s lead­ing pro­duc­ers of quartzite, rank­ing third in terms of reserves after Rus­sia and Kaza­khstan, and sec­ond only to Rus­sia in terms of pro­duc­tion. The main deposits are locat­ed with­in the Ukrain­ian Shield (US) and the Dnieper-Donets Basin.

The total bal­ance reserves of quartzite in Ukraine amount to over 181 mil­lion tons, with the largest share in the Zhy­to­myr region (140 mil­lion tons). The Dnipropetro­vsk region has over 26 mil­lion tons of quartzite, and the Kirovohrad region has about 15 mil­lion tons. A sep­a­rate deposit of quartzite-like sand­stones in the Sumy region stands out with reserves of 9.7 mil­lion tons.

Cur­rent­ly, three main quartzite deposits are being devel­oped in Ukraine: Ovrutske, Tovkachivske, and Mal­oskelu­vatske.

The Ovrutske deposit, locat­ed in the Zhy­to­myr region, is one of the old­est and largest quartzite deposits. It has been exploit­ed since 1936 and has pro­duc­tive reserves of pink quartzite used in the pro­duc­tion of dinas refrac­to­ries and fer­roal­loys. Annu­al pro­duc­tion here is 2.3–2.5 mil­lion tons, of which about 1.5–1.8 mil­lion tons are used in the fer­roal­loy indus­try. Near­by is the Tovkachivske deposit, from which raw mate­ri­als are sup­plied to the Cher­vonoarmiysky dinas and Zapor­izhzhia fer­roal­loy plants.

The Kirovo­grad region is home to the Mal­oskelu­vatske and Ivanivske deposits, which con­tain high-qual­i­ty quartzites with a sil­i­con con­tent of up to 99.5%. They are raw mate­ri­als for the pro­duc­tion of fer­roal­loys, but are not suit­able for the pro­duc­tion of dinas.

The Banytske deposit in the Sumy region, where large deposits of quartzite sand­stone and quartzite have been explored, which are used in the pro­duc­tion of crys­talline sil­i­con and fer­roal­loys. The deposit is locat­ed in the Shost­ka dis­trict of the Sumy region, 20 km south of the city of Hlukhiv. Devel­op­ment of the deposit began in 1890, and since 1928 it has been devel­oped as an indus­tri­al facil­i­ty. In 1958, raw mate­ri­als from this deposit began to be used for the pro­duc­tion of crys­talline sil­i­con. The pro­duc­tive thick­ness of quartzite sand­stones belongs to the Buchach For­ma­tion (Eocene). The aver­age thick­ness is 9 m. In terms of raw mate­r­i­al qual­i­ty, the deposit is unique in its sil­i­ca con­tent – 99–99.9%. Reserves amount to 9.8 mil­lion tons, and the quar­ry area is 20 hectares.

Low­er-qual­i­ty raw mate­ri­als are also mined near the vil­lages of Khovziv­ka and Rud­ne­vo, with a sil­i­ca con­tent of 65–68%. Sim­i­lar in quan­ti­ty and qual­i­ty of reserves to the Ban­nit­sa deposit is the Mat­sivske deposit of quartzite sand­stones. It is locat­ed 5 km north­west of the Ban­nit­sa deposit. Pre­lim­i­nary explo­ration has been car­ried out at the deposit. Due to the dif­fi­cult con­di­tions and unprof­itabil­i­ty of devel­op­ment, it was not rec­om­mend­ed for fur­ther detailed explo­ration.

Prospects for exploration and extraction

Ukraine has sig­nif­i­cant prospects for expand­ing quartzite min­ing, espe­cial­ly in the Zhy­to­myr and Kirovohrad regions, where esti­mat­ed resources exceed 2.5 bil­lion tons. Promis­ing areas for geo­log­i­cal explo­ration are locat­ed in the Ovruch, Olevsk, Prya­zovia, and Donet­sk regions.

Giv­en the grow­ing demand for sil­i­con, fer­roal­loys, and refrac­to­ries, fur­ther devel­op­ment of quartzite deposits in Ukraine could con­tribute to the devel­op­ment of the met­al­lur­gi­cal com­plex, con­struc­tion, and elec­tron­ics indus­tries. The use of mod­ern enrich­ment meth­ods and opti­miza­tion of logis­tics will increase the prof­itabil­i­ty of quartzite extrac­tion and export to the world mar­ket.