Process

The rapid increase in the production and consumption of electronic and electrical equipment has resulted in a significant global increase in electronic waste (e-waste). This complex waste stream has valuable rare earth elements, precious metals, and base metals, positioning it as an important secondary resource for the recovery of critical metals. With proper extraction and recovery technologies, e-waste presents a…

Hydrogen processing of magnetic scrap (HPMS) is a promising short-loop route for recycling end-of-life NdFeB permanent magnets; however, the resulting hydrogenated powder requires vacuum degassing before reuse. This study defines a phenomenological degassing window for HPMS jet-milled powder from end-of-life wind-turbine magnets by screening degassing temperature (650–900 °C), heating rate (1–3 °C/min), and dwell time (5–60 min) under vacuum. Pressure–temperature…

To address the marked differences in the host phases of phosphorus and vanadium, severe ore sliming, and the difficulty of synergistic recovery from the low-grade phosphorus–vanadium-associated ore in Mazharweina, Xinjiang, process mineralogical analysis, phosphorus flotation condition tests, and acid leaching-solvent extraction tests were conducted to investigate phosphorus and vanadium recovery from this ore. The results showed that the P2O5 and…

Spent lithium-ion battery (LIB) cathodes were investigated as a multimetallic resource for catalyst precursor synthesis. Cathode material was leached under ultrasound using citric or sulfuric acid, with and without H2O2, to compare metal recovery, stability, and thermal transformation. Sulfuric acid with H2O2 achieved the highest extraction efficiencies, with 93.10% Co and 97.15% Mn, while Li extraction exceeded 95%. Maximum sulfuric…

Platinum group metals (PGMs) are key components of automotive emission-control catalysts, and spent automotive catalysts (SACs) are their main secondary source. This paper reviews hydrometallurgical, pyrometallurgical, magnetic-separation, biometallurgical, and ionic-liquid/deep-eutectic-solvent (IL/DES) routes and compares them for recovery, selectivity, energy demand, reagent hazard, technology readiness, and scalability, using values re-checked against accessible primary sources. Smelting with Cu- or Fe-based collectors is…

A shared calibration matrix for Fe²⁺/Fe³⁺ determination across Mössbauer, XANES, Raman, and wet chemistry.

Charging direct reduced iron (DRI) into a blast furnace alters the softening–melting–dripping behavior of mixed burdens; however, the influencing laws and mechanisms remain unclear. In this study, DRI, pellets, and sinter were used as raw materials to systematically investigate the effect of DRI proportion (0–40%) on the softening–melting–dripping behavior of mixed burdens, and the underlying mechanism was revealed by combining…

The recovery of platinum group metals (PGMs) from acidic chloride media using anion exchange resins is strongly influenced by metal speciation, competitive adsorption, mass transfer limitations, and regeneration behavior. This study investigates the adsorption and desorption of Pt(IV), Pd(II), and Rh(III) from acidic chloride media using Puromet MTA4801PF, a gel-type strong base anion exchange resin functionalized with pyridinium groups. A…

Effective management and safe disposal of hazardous industrial waste remain critical challenges for sustainable construction. Aluminum-anodizing and nickel-electroplating sludges (AAS and NES) pose several environmental risks. This study focuses on developing multifunctional, ternary-blended alkali-activated materials from ground-granulated blast-furnace slag (GGBFS), AAS and NES, combining adequate mechanical performance, heavy-metal immobilization (Ni) and gamma-ray shielding. The composites were designed by replacing 10-30…

Blast furnace sludge (BFS) is an iron-rich residue (14.48% Fe) whose zinc content (2.15%) limits its direct recycling to the blast furnace. Extracting zinc selectively while leaving iron in the solid would allow this reuse, and organic complexing agents have been proposed for this purpose. However, their performance has been studied mainly through operating variables, and the role of particle…