Critical Raw Materials

Recycling large-tonnage copper slag as a secondary source of iron in the form of magnetite is limited by the liberation of finely disseminated phases, whereas particle shape has so far been regarded as a consequence of breakage rather than a controllable feed parameter. In the finite element model, particle contours were taken from optical micrographs, while the third dimension and…

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…

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…

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…

The development of sustainable metallurgical routes aimed at reducing CO 2 emissions has renewed interest in alternative reductants for alloy production. Secondary aluminium, due to its strong reducing potential and high reaction enthalpy, represents a promising candidate for aluminothermic processing. The choice of reductant plays a critical role in governing the microstructure and physicochemical properties of the resulting alloy. In…

Part 1 of this study identified the recovery of ultrafine particles as the main bottleneck in the decanter centrifuge dewatering of bauxite tailings. This study (Part 2) develops a semi-empirical framework that reconstructs the Whiten partition parameters (corrected cut size d50c, sharpness α, and hydraulic bypass Rf) and the cake solids content from bench-scale characterization, operating and equipment parameters, and…

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…

Recovery routes, mineralogy, and re-use pathways for red mud across construction and critical-metal streams.

A community round-robin preprint. The discussion closed after six weeks and three revisions.

The utilization of mineral carbon sequestration technology has emerged as a promising approach for mitigating CO2 emissions in recent years. This study aimed to assess the carbon sequestration potential of mineral tailings across the administrative divisions of Sichuan Province, including prefectures and cities. The approach outlined in the IPCC Guidelines for National Greenhouse Gas Inventories and an enhanced version of…

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…