History of steelmaking

Bakalářská práce je odbornou rešerší, popisující historii výroby oceli se zaměřením na období od 50. let 20. století po současnost. Stručně byla popsána dávná historie výroby železa a oceli. Dále se práce zabývá rozdělením, složením a strukturou ocelí, principem výroby surového železa a následně byly popsány principy výroby oceli – elektrické pece, kyslíkové konvertory a základní postupy sekundární metalurgie. Je zde i zmínka o metodě přímé výroby železa z rud.Bachelor´s thesis is a technical summary describing the history of steelmaking. It is focused on time period from 1950s to nowadays. There has been mentioned the ancient history of steelmaking and ironmaking. The thesis also deals with kinds, composition and structures of the steel, with principle of making row iron and also priciples of steelmaking – electric furnace, oxygen converter and basic procedures of secondary metallurgy. There is mentioned a direct making of iron from the ore as well.

Graphite-tremolite rocks at Bačkovice near Jemnice (West Moravia)

Graphite-tremolite rocks at Bačkovice, with simple mineral assemblage (tremolite, graphite, biotite, titanite and chlorite), represent rare rocks type in the Gföhl unit (Moldanubicum). Chemical composition and mineralogy indicate that protholite is a volcano-sedimentary Ca-rich rocks rather than basic or ultrabazic igneous rocks.Graphite-tremolite rocks at Bačkovice, with simple mineral assemblage (tremolite, graphite, biotite, titanite and chlorite), represent rare rocks type in the Gföhl unit (Moldanubicum). Chemical composition and mineralogy indicate that protholite is a volcano-sedimentary Ca-rich rocks rather than basic or ultrabazic igneous rocks

Olivine- and spinel-bearing chlorite hornblendite from Loukovice near Moravské Budějovice (Moldanubicum, western Moravia)

Ultramafic rock was found in the Varied Group of Moldanubicum near Loukovice (western Moravia). It is composed predominantly by chlorite and amphibole, locally rich in ferroan spinel and serpentinised magnesian olivine (Fo = 73–81 mol. %). Their current mineral assemblage originally corresponded to pyroxenic peridotite (olivine and/or pyroxene-rich rock) metamorphosed under upper amphibolite facies conditions. Older mineral assemblage Ol + Cpx + Opx + Sp indicates the temperature 786–804 °C for pressures near 8 kbar. Amphibole (magnesiohornblende) and chlorite (clinochlore) formed during the metamorphosis at temperatures of 714 ± 34 °C and expected pressures around 8 kbar or less.Ultramafic rock was found in the Varied Group of Moldanubicum near Loukovice (western Moravia). It is composed predominantly by chlorite and amphibole, locally rich in ferroan spinel and serpentinised magnesian olivine (Fo = 73–81 mol. %). Their current mineral assemblage originally corresponded to pyroxenic peridotite (olivine and/or pyroxene-rich rock) metamorphosed under upper amphibolite facies conditions. Older mineral assemblage Ol + Cpx + Opx + Sp indicates the temperature 786–804 °C for pressures near 8 kbar. Amphibole (magnesiohornblende) and chlorite (clinochlore) formed during the metamorphosis at temperatures of 714 ± 34 °C and expected pressures around 8 kbar or less

A new occurrence of skarn in the Gföhl unit at Vevčice near Jevišovice: the mineral assemblage of skarn and contaminated amphibole-bearing pegmatites

This work provides detailed information about a new occurrence of skarn near Vevčice (near Jevišovice, western Moravia), which is one of the most important outcrops of these rocks in the southeastern part of the Moldanubian Zone (Gföhl Unit). The skarn is characterized by a strong migmatization, which resulted in contaminated amphibole pegmatite veins penetrating the skarn. The mineral assemblage of the skarn is simple, with dominant garnets, both grossular-almandine (Alm55–57 Grs31–37 Adr3–8) and grossular-andradite-almandine (Grs45–53 Adr20–34 Alm20–24). Garnets clearly predominate over clinopyroxene, hedenbergite with a slightly increased “fassaite component”. The very low amount of quartz contrasts with that in the skarns in the surrounding Gföhl unit. Amphibole (potassium-rich hastingsite) is younger mineral in the skarn, and especially in contaminated pegmatites. Epidote after garnets, and eventually prehnite, belong to the youngest minerals in some types of rocks. Accessory titanite, sometimes rich in Sn, was found frequently, as well as metamict REE-rich epidote. Magnetite is rather exceptional, mainly in assemblages replacing garnet; fluorapatite, ilmenite and zircon are rare. The studied skarn is part of a lithologically varied sequence of the Gföhl Unit, with intercalations of Ca-metasediments, appearing in several non-contiguous horizons around the boundary of so-called Běhařovice-Vémyslice synform, with a granulite–serpentinite complex in its center. This sequence of strongly migmatized biotite paragneiss to leucocratic migmatites also contains diopside and scapolite-diopside gneiss, garnet-pyroxene and phlogopite-diopside skarns containing magnetite and exceptionally Au-Co-Bi and REE mineralization as well as rare occurrences of spinel-forsterite dolomitic marbles. This work provides detailed information about a new occurrence of skarn near Vevčice (near Jevišovice, western Moravia), which is one of the most important outcrops of these rocks in the southeastern part of the Moldanubian Zone (Gföhl Unit). The skarn is characterized by a strong migmatization, which resulted in contaminated amphibole pegmatite veins penetrating the skarn. The mineral assemblage of the skarn is simple, with dominant garnets, both grossular-almandine (Alm55–57 Grs31–37 Adr3–8) and grossular-andradite-almandine (Grs45–53 Adr20–34 Alm20–24). Garnets clearly predominate over clinopyroxene, hedenbergite with a slightly increased “fassaite component”. The very low amount of quartz contrasts with that in the skarns in the surrounding Gföhl unit. Amphibole (potassium-rich hastingsite) is younger mineral in the skarn, and especially in contaminated pegmatites. Epidote after garnets, and eventually prehnite, belong to the youngest minerals in some types of rocks. Accessory titanite, sometimes rich in Sn, was found frequently, as well as metamict REE-rich epidote. Magnetite is rather exceptional, mainly in assemblages replacing garnet; fluorapatite, ilmenite and zircon are rare. The studied skarn is part of a lithologically varied sequence of the Gföhl Unit, with intercalations of Ca-metasediments, appearing in several non-contiguous horizons around the boundary of so-called Běhařovice-Vémyslice synform, with a granulite–serpentinite complex in its center. This sequence of strongly migmatized biotite paragneiss to leucocratic migmatites also contains diopside and scapolite-diopside gneiss, garnet-pyroxene and phlogopite-diopside skarns containing magnetite and exceptionally Au-Co-Bi and REE mineralization as well as rare occurrences of spinel-forsterite dolomitic marbles

Chromium-rich illite/smectite in the basal Balinka Conglomerate of the Upper Carboniferous-Permian Boskovice Basin (Bohemian Massif). Annales Societatis Geologorum Poloniae

The Upper Carboniferous polymictic Balinka Conglomerate was deposited along the western margin of the Boskovice Basin (eastern part of the Bohemian Massif). Angular aggregates of deep-green chromium-rich interstratified clay mineral R1-illite(0.8)/smectite (I/S) are present exclusively in the basal part of this unit. The textural position of chromium-bearing I/S (0.77–2.88 wt.% Cr2O3; 0.040–0.153 apfu Cr) in the conglomerate matrix indicates a genetic link with the highly altered chromium spinel, which is preserved in the relics. The source of Cr-rich spinelides was serpentinized peridotites in the adjacent Moldanubicum (Gföhl Unit). The formation of I/S is related to diagenetic processes in the conglomerate matrix. The fluids would have relatively high fugacity of CO2 and activity of K+. K/Ar ages of 284.1 ± 7.7 and 276.3 ± 7.4 Ma (lower Permian – Kungurian/Artinskian age) confirmed the diagenetic origin of this I/S