This study is concerned with the characterization of iron nuggets obtained from the reduction of an iron oxide concentrate in a microwave oven using a biomass-based reducing agent. In the experiments, the concentrate of iron ore consisting of hematite and magnetite minerals supplied from Elazig region and containing 67.29% Fe after enrichment, and as a reducing agent, tea plant wastes containing 94.68% C and 0.03% S after carbonization was used. Carbon required for the reduction of iron oxides to iron was stoichiometrically added to the concentrate with a grain size of -45 µm after its basicity ratio was adjusted. The composite pellets produced after the addition of reducing agent and flux (CaO) were subjected to reduction in a household microwave oven at different times. After the process, optimum (Fe3O4+Fe2O3)/C=1/4, basicity ratio (CaO+MgO)/(SiO2+Al2O3) =1.2 results were obtained. It was seen that the metallic part contained 96.6% Fe, 2.4% C after being separated from the slag and that the metallic phase was separated from the slag very easily. As a result of the microstructure investigations, it was found that the product obtained had similar properties to white cast iron properties.

This study investigates the recycling of industrial waste copper chips generated during the processing of copper chips containing approximately 5% magnesium. An innovative patented modification was integrated with the classical solid-state sintering method to directly produce copper ingots from these wastes. Unlike conventional powder metallurgy techniques, the process employs a low-pressure (7 bar) and short-term (5 minute) sintering step without prior surface cleaning. Initially, the chips undergo pre-compression at 200°C, followed by heat treatment at 1035°C, and subsequently a secondary pressing to yield copper ingots. X-ray diffraction analysis predominantly identified the face-centered cubic copper phase, while energy dispersive spectroscopy indicated only trace amounts of oxygen and iron. The abbreviated sintering duration successfully preserved over 97% of the metallic copper phase and minimized oxide formation. Scanning electron microscopy confirmed a homogeneous microstructure, with crystallite sizes and morphology optimized based on the sintering conditions. This approach offers substantial advantages in terms of energy savings, production efficiency, and environmental sustainability.

In this study, ceramic samples with perlite additions in the range of 0–50% were sintered at 1050, 1150, and 1250 °C to investigate their effects on phase stability, microstructural evolution, and microstrain. The XRD patterns revealed that the quartz-dominant phase environment was preserved, and the broad amorphous hump at 2θ ≈ 8–16° persisted in all groups. Scherrer analysis indicated that crystallite size reached its maximum (11–12 nm) in samples containing 10–20% perlite at 1150 °C, whereas it decreased to as low as 2–3 nm at ≥40% perlite additions at 1250 °C. The Williamson–Hall method demonstrated a pronounced increase in microstrain at 1250 °C, peaking particularly around 40% perlite. SEM-based dark-field (%) analysis showed more compact and homogeneous structures at medium additions (20–40%), while higher additions tended to cause structural heterogeneity. Furthermore, microhardness measurements supported the observed structural trends. Overall, the findings suggest that the optimum microstructural features (10–20% perlite at 1150 °C) were achieved through low microstrain, high crystallinity, and balanced crystallite size, while excessive perlite additions under advanced sintering conditions disrupted the morphology. These results contribute to defining the optimum perlite ratio in ceramic body design.

This study comparatively examines the effect of 50% perlite addition on phase assemblage, pore architecture, and mechanical behavior in pumice-based ceramic bodies sintered at 1150 °C, against the perlite-free reference P00. Fast-scan XRD (10–90° 2θ) indicates no new crystalline phases in either body and shows coincident peak positions. A semi-quantitative reading via window integration (RIR = 1) reveals phase distributions in both samples of ~55% mullite, ~43% alkali feldspar, and ~1–2% quartz. In contrast, SEM-based morphometry shows that perlite significantly alters the pore architecture: the area fraction of open porosity changes from 60.4 ± 22.3% (P00) to 74.7 ± 6.7% (P50); the median equivalent diameter from 1.46 ± 1.53 µm to 2.46 ± 0.50 µm; the p90 from 5.18 ± 4.03 µm to 20.98 ± 11.50 µm; and the void count from 177 to 49. Archimedes densities are similar (1150-P00: 2.3373 g cm⁻³; 1150-P50: 2.3215 g cm⁻³). Mechanically, the compressive strength in P50 decreases by ~78%, from 36.6 MPa to 8.0 MPa, while microhardness remains statistically equivalent—638 ± 19 HV (P00) vs. 648 ± 24 HV (P50). Additionally, for 1150-P00, SBET ≈ 22.5 m² g⁻¹ and Vp ≈ 0.020 cm³ g⁻¹ were measured. Taken together, the findings indicate that at 1150 °C the phase types are essentially preserved, and the dominant lever on performance is the pore-size distribution and connectivity: a reduced effective load-bearing area lowers compressive strength, whereas the local matrix—retaining its phase/chemical makeup—sustains largely unchanged microhardness.

Iron and steel manufacturing generates significant industrial waste, including mill scale, rich in valuable metal content. This study investigates the potential of mill scale recovery for metallic iron and the use of almond shells as an organic substitute for coke in reduction processes. Carbonization conditions for almond shells and advanced milling methods for both mill scale and carbonized almond shells are examined to enhance surface area and reactivity. Reduction experiments at varying temperatures unveil the metallization potential of mill scale. Notably, reduction at 1200 °C for 120 minutes achieves the highest metallic iron content of 94.6%. According to the results obtained, the use of carbonized almond shell significantly contributed to the reduction of mill scale material, and has thus been considered as an effective biomaterial in this context. These findings propose a sustainable solution for iron and steel production, offering an alternative and eco-friendly iron source for blast furnaces and electric arc furnaces.