scholarly journals Strusky a železo z experimentální tavby železa realizované na hradě Buchlově (jv. Chřiby) v roce 2018

2020 ◽  
Vol 28 (1) ◽  
pp. 58-68
Author(s):  
Zdeněk Dolníček ◽  
Ladislav Kandrnál ◽  
Jana Ulmanová ◽  
Ester Vratislavská ◽  
Pavel Hojač
Keyword(s):  
Phase Composition ◽  
Chemical Composition ◽  
Metallic Iron ◽  
Glass Phase ◽  
Iron Ore ◽  
Shaft Furnace ◽  
Early Period ◽  
Direct Production ◽  
Spherical Inclusions ◽  
Furnace Slag

During experimental smelting of iron in a replica of historical shaft furnace, which was held at the Buchlov Castle in 2018, charcoal and Mn-enriched pelosiderite-limonite iron ore from the locality Strážovice near Kyjov were used. The obtained furnace slag is practically completely formed by glass phase; only rare small domains also contain olivine. The glass phase is compositionally heterogeneous and contains 0.7 - 10.7 wt. % MnO, whereas olivine corresponds to fayalite with elevated contents of tephroite (ca. 12 mol. %), forsterite (ca. 4 mol. %) and dicalciumsilicate (1 mol. %) components. The produced metallic iron is also compositionally heterogeneous, rich in phosphorus and in places it contains small spherical inclusions of pyrrhotite. The phase composition of slag differs significantly from those of typical iron slags. The reason can be seen either in anomalous chemical composition of used ore (the elevated contents of Mn could potentially act as an inhibitor of crystallization), or in too high temperatures during smelting (the phase relations in metallic iron suggest temperatures exceeding 1500 °C) in combination with rapid cooling of the furnace content after finishing of smelting. Both phase composition of slag as well as chemical composition of individual slag phases and metallic iron are significantly different from those of local historical artefacts from the period of usage of technology of direct production of iron. These findings do not support the idea that local pelosiderite iron ores were used for production of iron already during this early period.

scholarly journals Strusky z redukční tavby pelosideritové železné rudy realizované na hradě Buchlově (jv. Chřiby) v roce 2019: extrémní variabilita fázového složení a chemismu jednotlivých fází

2021 ◽  
Vol 29 (1) ◽  
pp. 59-76
Author(s):  
Zdeněk Dolníček ◽  
Ladislav Kandrnál ◽  
Jana Ulmanová ◽  
Ester Vratislavská ◽  
Pavel Hojač
Keyword(s):  
Phase Composition ◽  
Chemical Composition ◽  
Metallic Iron ◽  
Glass Phase ◽  
Shaft Furnace ◽  
Early Period ◽  
Crystalline Phases ◽  
Direct Production ◽  
Natural Systems ◽  
Slag Melt

During experimental smelting of iron in a replica of historical shaft furnace, which was held at the Buchlov Castle in 2019, charcoal and fresh pelosiderite iron ore from the locality Moravany near Kyjov were used. The obtained furnace slag is practically completely formed by glass phase; only rare small domains contain also crystalline phases, whose occurrence is very irregular. A detailed study of chemical composition showed extreme heterogeneity in composition of glass and most crystalline phases. The glass phase contains variable, but often high amounts of Mn, Ca, Mg and sometimes P and/or K. The composition of olivine ranges widely among fayalite, dicalciumsilicate and tephroite (Fa1-91 Fo3-28Te2-45DCS1-52), as well as those of calcic pyroxene (Wo37-60Tsch1-13Ka8-22Fs4-30En14-36). Feldspars showed compositions between orthoclase and anorthite (Or2-82An9-91Ab5-19Cn0-2Slw0-2), which are unknown from natural systems. Minor components include wüstite, melilite (åkermanite with 1 - 6 mol. % gehlenite), leucite, kalsilite, locally also apatite and an unnamed phase with composition close to Ca2Al2Si3O11. The produced metallic iron is also compositionally heterogeneous and rich in phosphorus. The phase composition of slag differs significantly from those of typical iron slags. The reason can be seen in anomalous chemical composition of used ore, in too high temperatures during smelting (phase relations in metallic iron suggest temperatures around 1500 °C) in combination with rapid cooling of the furnace content after finishing of smelting, and probably also higher viscosity of slag melt. Both phase composition of slag as well as chemical composition of individual slag phases and metallic iron are significantly different from those of local historical artefacts from the period of usage of technology of direct production of iron. These findings do not support the idea that local pelosiderite iron ores were used for production of iron already during this early period.

scholarly journals Phase Composition of Iron Ore Sinters Produced with Biomass as a Substitute for the Coke Fuel / Skład Fazowy Spieków Żelaza Wytworzonych Z Dodatkiem Biomasy Jako Zamiennika Dla Koksu

2015 ◽  
Vol 60 (4) ◽  
pp. 2955-2964 ◽  
Author(s):  
R. Mežibrický ◽  
M. Fröhlichová ◽  
A. Mašlejová
Keyword(s):  
Phase Composition ◽  
Chemical Composition ◽  
Iron Ore ◽  
Negative Impact ◽  
Thermal Conditions ◽  
Walnut Shell ◽  
Mineral Matter ◽  
Phase Identification ◽  
Mineral Phases ◽  
Key Factor

The effort to minimize CO2 emissions leads the existing integrated steel plants to implement alternative biomass-based fuels that dispose of equilibrium carbon balance. The fuel is a key factor in the iron ore sinter production, so it is essential to know its impact not just on mechanical properties of the finished sintered ore but also on the mineral composition as the mineral phases together determine all observed sinter properties. For this purpose the samples prepared by replacing a part of coke breeze with charcoal or walnut shell substitute were subjected to the observation under the light microscope, also using etching, to the phase identification by chemical EDX analysis on the scanning electron microscope and to the phase composition quantification by X-Ray diffraction analysis. The studied microstructure areas in the vicinity of the pores left by fuel grains were neither characterized by different phases nor by changed chemical composition of these phases even thought mineral matter of the used fuels were substantially different in terms of the chemical composition. The only feature of the burned substitute fuels were ash particles arranged in characteristic shapes. The main reason of variation in ratios of respective mineral phases of samples appeared to be thermal conditions that were reflected in the content of unreacted non-ferrous phases. Coke substitution in the sinter mixture has no negative impact on the phase composition of the produced sinters, which confirms the prospective use of biofuels in the sintering process.

Structural Analysis of Sinter with Titanium Addition / Analiza Strukturalna Spieku Z Dodatkiem Tytanu

2013 ◽  
Vol 58 (1) ◽  
pp. 179-185 ◽  
Author(s):  
M. Fröhlichová ◽  
R. Findorák ◽  
J. Legemza
Keyword(s):  
Phase Composition ◽  
Chemical Composition ◽  
Iron Ore ◽  
Strength Properties ◽  
X Ray Diffraction ◽  
Sinter Production ◽  
Titanium Addition ◽  
X Ray ◽  
Iron Ore Sinter ◽  
The Relationship

Paper presents the results from the study of the effect of materials with titanium addition on the strength properties of the iron ore sinter. The sinters with TiO2 addition or without TiO2 addition prepared in laboratory were applied in this research and were compared based on the structural and phase composition. Exploited was the method of the X-ray diffraction and method of elemental EDX analysis applying the electron raster microscope with the energo-dispersion analyser. Confirmed was the relationship between the sinter structure and its strength. Higher strength of the sinter without TiO2 addition is the result of the different phase composition of the compared sinters. In the sinter production considered should be not only the chemical composition of the entry components of the charge and the chemical composition of the final product but also its structural and phase composition.

scholarly journals Influencing Factors of the Mineral Carbonation Process of Iron Ore Mining Waste in Sequestering Atmospheric Carbon Dioxide

2021 ◽  
Vol 13 (4) ◽  
pp. 1866
Author(s):  
Noor Allesya Alis Ramli ◽  
Faradiella Mohd Kusin ◽  
Verma Loretta M. Molahid
Keyword(s):  
Carbon Dioxide ◽  
Particle Size ◽  
Chemical Composition ◽  
Iron Ore ◽  
Divalent Cations ◽  
Mining Industry ◽  
Mining Waste ◽  
Aluminum Silicate ◽  
Mineral Carbonation ◽  
Carbonation Process

Mining waste may contain potential minerals that can act as essential feedstock for long-term carbon sequestration through a mineral carbonation process. This study attempts to identify the mineralogical and chemical composition of iron ore mining waste alongside the effects of particle size, temperature, and pH on carbonation efficiency. The samples were found to be alkaline in nature (pH of 6.9–7.5) and contained small-sized particles of clay and silt, thus indicating their suitability for mineral carbonation reactions. Samples were composed of important silicate minerals needed for the formation of carbonates such as wollastonite, anorthite, diopside, perovskite, johannsenite, and magnesium aluminum silicate, and the Fe-bearing mineral magnetite. The presence of Fe2O3 (39.6–62.9%) and CaO (7.2–15.2%) indicated the potential of the waste to sequester carbon dioxide because these oxides are important divalent cations for mineral carbonation. The use of small-sized mine-waste particles enables the enhancement of carbonation efficiency, i.e., particles of <38 µm showed a greater extent of Fe and Ca carbonation efficiency (between 1.6–6.7%) compared to particles of <63 µm (0.9–5.7%) and 75 µm (0.7–6.0%). Increasing the reaction temperature from 80 °C to 150–200 °C resulted in a higher Fe and Ca carbonation efficiency of some samples between 0.9–5.8% and 0.8–4.0%, respectively. The effect of increasing the pH from 8–12 was notably observed in Fe carbonation efficiency of between 0.7–5.9% (pH 12) compared to 0.6–3.3% (pH 8). Ca carbonation efficiency was moderately observed (0.7–5.5%) as with the increasing pH between 8–10. Therefore, it has been evidenced that mineralogical and chemical composition were of great importance for the mineral carbonation process, and that the effects of particle size, pH, and temperature of iron mining waste were influential in determining carbonation efficiency. Findings would be beneficial for sustaining the mining industry while taking into account the issue of waste production in tackling the global carbon emission concerns.

Modeling of Alteration Behavior on Blended Cementitious Materials

2011 ◽  
Author(s):  
Hitoshi Owada ◽  
Tomoko Ishii ◽  
Mayumi Takazawa ◽  
Hiroyasu Kato ◽  
Hiroyuki Sakamoto ◽  
...  
Keyword(s):  
Blast Furnace ◽  
Fly Ash ◽  
Chemical Composition ◽  
Mineral Composition ◽  
Blast Furnace Slag ◽  
Fine Powder ◽  
Cementitious Materials ◽  
Leaching Tests ◽  
Measured Concentration ◽  
Furnace Slag

A “realistic alteration model” is needed for various cementitious materials. Hypothetical settings of mineral composition calculated based on the chemical composition of cement, such as Atkins’s model, have been used to estimate the alteration of cementitious material. However, model estimates for the concentration of certain elements such as Al and S in leachate have been different from experimental values. In a previous study, we created settings for a mineralogical alteration model by taking the initial chemical composition of cementitious materials from analysis results in experiments and applying their ratios to certain hydrated cement minerals, then added settings for secondary generated minerals in order to account for Ca leaching. This study of alteration estimates for ordinary portland cement (OPC) in groundwater showed that the change in Al and S concentrations in simulated leachate approached values for actual leachate[1]. In the present study, we develop an appropriate mineral alteration model for blended cementitious materials and conduct batch-type leaching experiments that use crushed samples of blast furnace slag cement (BFSC), silica cement (SC), and fly ash cement (FAC). The cement blends in these experiments used OPC blended with blast furnace slag of 70 wt.%, silica cement consisting of an amorphous silica fine powder of 20 wt.%, and fly ash of 30 wt.%. De-ionized water was used as the leaching solution. The solid-liquid ratios in the leaching tests were varied in order to simulate the alteration process of cement hydrates. The compositions of leachate and minerals obtained from leaching tests were compared with those obtained from models using hypothetical settings of mineral composition. We also consider an alteration model that corresponds to the diversity of these materials. As a result of applying the conventional OPC model to blended cementitious materials, the estimated Al concentration in the aqueous solution was significantly different from the measured concentration. We therefore propose an improved model that takes better account of Al behavior by using a more reliable initial mineral model for Al concentration in the solution.

Phosphorus retention capacity of iron-ore and blast furnace slag in subsurface flow constructed wetlands

2001 ◽  
Vol 44 (11-12) ◽  
pp. 69-75 ◽  
Author(s):  
B. Grüneberg ◽  
J. Kern
Keyword(s):  
Blast Furnace ◽  
Constructed Wetlands ◽  
Blast Furnace Slag ◽  
Iron Ore ◽  
Subsurface Flow ◽  
Phosphorus Retention ◽  
Anaerobic Conditions ◽  
Retention Capacity ◽  
Aerobic Conditions ◽  
Furnace Slag

The suitability of iron-ore and blast furnace slag for subsurface flow (SSF) constructed wetlands was studied over a period of four months. Dairy farm wastewater (TP 45 mg l-1) was percolated through buckets planted with reed (volume 9.1 l; hydraulic load 15 l m-2d-1). One group of buckets was kept under aerobic conditions and the other group under anaerobic conditions, monitored by continuous redox potential measurements. Even at high mass loading rates of 0.65 g P m-1d-1 the slag provided 98% removal efficiency and showed no decrease in performance with time. However, phosphorus fractionation data indicate that the high phosphorus retention capacity under aerobic conditions is to a great extent attributable to unstable sorption onto calcium compounds (NH4Cl-P). Phosphorus sorption of both the slag (200 μg P g-1) and the iron-ore (140 μg P g-1) was promoted by predominantly anaerobic conditions due to continuous formation of amorphous ferrous hydroxides. None of the substrates had adverse affects on reed growth.

scholarly journals PROPERTIES OF CONCRETE USING BLAST-FURNACE SLAG CEMENT TYPE A WITH MODIFIED CHEMICAL COMPOSITION

2010 ◽  
Vol 64 (1) ◽  
pp. 244-250 ◽  
Author(s):  
Shingo MIYAZAWA ◽  
Takashi YOKOMURO ◽  
Hiromi FUJIWARA ◽  
Kiyoshi KOIBUCHI
Keyword(s):  
Blast Furnace ◽  
Chemical Composition ◽  
Blast Furnace Slag ◽  
Type A ◽  
Cement Type ◽  
Slag Cement ◽  
Furnace Slag

scholarly journals Research into the chemical composition of refinery slag from silicon production for its efficient recycling

2021 ◽  
Vol 25 (2) ◽  
pp. 252-263
Author(s):  
N. V. Nemchinova ◽  
V. V. Hoang ◽  
I. I. Aponchuk
Keyword(s):  
Chemical Composition ◽  
Crystalline Silicon ◽  
Raw Material ◽  
Smelting Process ◽  
Elemental Silicon ◽  
Silicon Production ◽  
X Ray ◽  
Industrial Material ◽  
Furnace Slag ◽  
Oxidation Refining

The aim was to investigate the chemical composition of refinery slag obtained during silicon production in order to identify approaches to its further recycling. Research samples were collected from the slag remained after oxidation refining at the JSC Silicon (AO Kremny), RUSAL (Shelekhov, Irkutsk Oblast). The methods of X-ray phase, X-ray fluorescence, metallographic and scanning electron microscopy were employed to investigate the chemical composition of the samples. It was found that the refinery slag under study includes such basic components as elemental silicon, its carbide and oxide, as well as elemental carbon. It was shown that silicon carbide is the product of incomplete reduction, resulting from melting silica-containing ores in a smelting furnace. According to the conducted X-ray fluorescent analysis, the samples also contain (wt %): Ca - 7.40; Al - 3.80; Fe - 0.30; Ba - 0.19; K - 0.14; Na - 0.09; Sr - 0.09; Mg - 0.08; Ti - 0.05; S - 0.02. Calcium and aluminium are present in the slag mostly in the form of oxides. Complex oxides of an anor-thite type were also found: CaO Al2O3 2SiO2. The refinery slag under study also features insignificant amounts of other metal oxides, which are released from the furnace slag forming during the smelting process. The slag produced by oxidation refining during crystalline silicon production is a technogenic raw material containing valuable components. Due to the significant content of silicon in the refinery slag (from 42% to 65%), the existing methods applied to recycle such an industrial material were analysed in terms of additional silicon extraction or production of commercial silicon-containing products, which are in demand in various industries.

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