Crystallization Kinetics of Iron Rich Glass-Ceramic Obtained from Waste of Steel Industry

Abstract

The main objective of this work was to study the crystallization kinetics of glass-ceramic obtained from steel waste. Two compositions were melted at about 1350 °C. The obtained frits were dried and re-melted. Each composition was then wet ground, dried, and chemically characterized (X-ray fluorescence and atomic absorption spectrometry), structurally (X-ray diffraction), and thermally (thermal differential analysis). Then the powders were compacted and the samples were dried and heat treated in a kiln between 690 and 890 °C. After, the crystallized bodies were ground and the crystalline phases were identified by X-ray diffraction. Results showed that the main formed crystalline phases were magnetite, hematite, Fe2.95Si0.05O4, and CaAl2Fe4O10. The activation energies obtained by the Kissinger method were between 348 and 423 kJ.mol-1, whereas the Avrami parameter was obtained between 0.76 and 1.1 indicating surface crystallization.

Evaluation of electrical properties of glass-ceramics obtained from mill scale

“…Several different approaches have been used for the valorization of these wastes considering the volumes generated globally, such as the sequestering of carbon dioxide in mineral form, known as mineral carbonation [16][17][18][19][20], and the production of artifacts from cementitious materials [21][22][23][24], pigments [25,26] and glass-ceramics [10,27]. However, there is still a need to increase the technical and economic value of this residue.…”

“…Also, compositional modifications can allow the development of glass-ceramic materials [10] with interesting electrical properties. For these applications, the evaluation of the electrical properties plays an important role in improving the viability of the use of mill scale.…”

“…Extensive research has been carried out worldwide aimed at finding suitable approaches to valorization of wastes generated from different manufacturing processes [1][2][3][4][5][6][7][8][9], including those of the steel industry [10]. Around 700 kg of waste are generated per ton of steel produced, and globally around 30 million tons of recyclable waste is generated per year [11].…”

Iron-Rich Glass-Ceramics Obtained from Mill Scale

“…One of them is known as mill scale generated during the steel lamination process. Among several alternatives of valorization, stands out the production of glass-ceramics [1]. In fact, the vitrification is known as an interesting way to become inert toxic elements and, when followed by a suitable heat treatment, one can obtain glassceramic materials [2].…”

“…Luza et al [1] studied the crystallization kinetic of two mill scale-based glass-ceramic compositions. It was possible to incorporate up to 24 wt% of iron into the glass after melting that, after heat treatment, generated the following crystalline phases: calcium sodium aluminate, Fe 2.95 Si 0.05 O 4 , CaAl 2 Fe 4 O 10 , hematite and magnetite.…”