Ankica Rađenović

Characterization of Ladle Furnace Slag from Carbon Steel Production as a Potential Adsorbent

A promising type of steel slag for applications is the ladle furnace (LF) slag, which is also known as the basic slag, the reducing slag, the white slag, and the secondary refining slag. The LF slag is a byproduct from further refining molten steel after coming out of a basic oxygen furnace (BOF) or an electric arc furnace (EAF). The use of the LF slag in further applications requires knowledge of its characteristics. The LF slag characterization in this paper has been performed using the following analytical methods: chemical analysis by energy dispersive spectrometry (EDS), mineralogical composition by X-ray diffraction (XRD), surface area properties by the Brunauer-Emmett-Teller (BET) and the Barrett-Joyner-Halenda (BJH) methods, surface chemistry by infrared absorption (FTIR) spectroscopy, and morphological analysis by scanning electron microscopy (SEM). The results showed that the main compounds are calcium, silicon, magnesium, and aluminium oxides, and calcium silicates under their various allotropic forms are the major compounds in the LF slag. Surface area properties have shown that the LF slag is a mesoporous material with relatively great BET surface area. The ladle furnace slag is a nonhazardous industrial waste because the ecotoxicity evaluation by its eluate has shown that the LF slag does not contain constituents which might in any way affect the environment harmfully.

The mechanism of nickel separation from carbon materials during high-temperature treatment, II. study of real systems

The coke used as feedstock in the production of graphite electrodes may contain only limited amounts of metallic microconstituents. One of the procedures for their separation from carbon materials is high-temperature treatment. This paper deals with the results of investigations of the mechanism of nickel separation from petroleum cokes as real carbon systems during high-temperature treatment up to 2400°C. The investigations were performed on coke samples obtained from various precursors from the Moslavina basin oil, whose content of nickel is known to be larger than that of the other originally traced metals. The identification of the nickel compounds in cokes heated to temperatures between 1250° and 2400°C points to alternation of their chemical composition in terms of formation of thermally more or less unstable compounds. With a rise in temperature, the nickel mass fraction diminishes, as do relative reflex intensities of the identified compounds. A relationship was established between the efficacy of nickel separation during high-temperature treatment (HTT) up to 2400°C, on the one hand, and its mass fraction and the type of chemical compounds present in petroleum cokes, on the other.

Geochemistry of Croatian superhigh-organic- sulphur Raša coal, imported low-S coal, and bottom ash: their Se and trace metal fingerprints in seawater, clover, foliage, and mushroom specimens

The Labin city area has represented the major Croatian coal mining, metal industry, and coal- fired electricity centre for more than two centuries. Th

The mechanism of nickel separation from carbon materials during high-temperature treatment, I. Study of ideal systems (graphite-NiO, graphite-NiS,NiS1.03, graphite-NiSO4, graphite-NiO,NiS,NiS1.03, NiSO4)

Abstract The aim of the study was to determine the relationship between the types of chemical nickel compounds and the efficacy of nickel separation during the high-temperature treatment of ideal carbon systems: graphite-NiO, graphite-NiS, Nis1.03, graphite-NiSO4, and graphite-NiO,NiS,NiS1.03, NiSO4. The nickel compounds present were identified by X-ray diffraction before and after treatment of the samples at maximum temperatures of 1500°, 2000°, and 2400°C. Quantiative measurements of the nickel content showed a decrease in mass fraction with a rise in temperature. The same trend was true for the relative reflex intensities of the nickel compounds. During high-temperature treatment the chemical nickel compounds present were transformed to thermally more or less unstable forms, thus facilitating nickel separation.