Synthesis of steel slag ceramics: chemical composition and crystalline phases of raw materials

Abstract

Two types of porcelain tiles with steel slag as the main raw material (steel slag ceramics) were synthesized based on the CaO-Al 2 O 3 -SiO 2 and CaO-MgO-SiO 2 systems, and their bending strengths up to 53.47 MPa and 99.84 MPa, respectively, were obtained. The presence of anorthite, α-quartz, magnetite, and pyroxene crystals (augite and diopside) in the steel slag ceramics were very different from the composition of traditional ceramics. X-ray diffraction (XRD) and electron probe X-ray microanalysis (EPMA) results illustrated that the addition of steel slag reduced the temperature of extensive liquid generation and further decreased the firing temperature. The considerable contents of glass-modifying oxide liquids with rather low viscosities at high temperature in the steel slag ceramic adobes promoted element diffusion and crystallization. The results of this study demonstrated a new approach for extensive and effective recycling of steel slag.

Development and Characterization of Glass-Ceramics from Combinations of Slag, Fly Ash, and Glass Cullet without Adding Nucleating Agents

“…The presence of titanium oxide was also detected, which could represent an important factor in the formation of glass-ceramics (as a nucleating agent) [8,32,33,34,35,36]. Similarly, the calcium content of around 1.2% and 1.6% (by weight) confirmed the feasibility of promoting devitrification processes and increasing the chemical stability and mechanical behavior of the glasses [6,13].…”

“…During elemental composition, oxides that act as network formers are required, specifically silicon oxide (SiO 2 ) and phosphorus oxide (P 2 O 5 ). Network-modifying oxides such as sodium oxide (Na 2 O), potassium oxide (K 2 O), magnesium oxide (MgO), calcium oxide (CaO), and oxides that act as intermediates (e.g., alumina (Al 2 O 3 ), titanium oxide (TiO 2 ), or ferric oxide (Fe 2 O 3 )) are necessary to stabilize the structure [13]. According to Erol et al [14], a significant amount of Fe 2 O 3 can be used as a nucleating agent in the production of glass-ceramics, providing an important advantage in developing a great variety of microstructures with different morphological conformations [14,15].…”

Effect of the addition of glasses as sintering aids on microstructure and properties of nanoalumina

“…In this case, K 2 O present in the precursor glass (G1) is slightly less active as a flux when compared to Na 2 O (used in G2 and G3 for example). Alkaline oxide act as modifiers connecting through ionic bounds to anions ne twork and such ions act breaking covalent bonds, as in the case of Si-O-Si, thereby causing the onset of oxygen atoms unbound in silica-based materials [16][17].…”

Effect of Fly Ash on the Properties of Ceramics Prepared from Steel Slag

“…The ceramics were sintered via the liquid phase sintering process. During the sintering process, the glass phase is generated, which is also an important factor affecting the performance [26]. On one hand, CaO and FeO are present in all of the samples, and their contents remain roughly the same.…”

“…According to the crystalchemical formula and the principle of electricalneutrality, the monovalent and divalent cations can be employed to maintain an aluminium-oxygen tetrahedral balance, resulting in the formation of [AlO4]2Mg, The ceramics were sintered via the liquid phase sintering process. During the sintering process, the glass phase is generated, which is also an important factor affecting the performance [26]. On one hand, CaO and FeO are present in all of the samples, and their contents remain roughly the same.…”