Selective recovery of lithium from spent lithium iron phosphate batteries: a sustainable process

A sustainable process for metal recycling from spent lithium-ion batteries using ammonium chloride.

Evaluation of red mud as a polymetallic source – A review

Comparison of microwave and conventional carbothermal reduction of red mud for recovery of iron values

Significantly unexploited red mud contains 0.5–1.7 kg/ton of rare earth metals (REMs) and 14–45% Fe, 5–14% Al, 1–9% Si, 1–6% Na, and 2–12% Ti which is currently being stockpiled. Reasonably, the re...

Red mud valorization an industrial waste circular economy challenge; review over processes and their chemistry

Bayer’s process revolutionized the extraction of aluminum from the bauxite ores. However, the hydrothermal extraction of alumina is associated with the generation of a byproduct, red-mud consisting of undissolved solids composed of iron oxides, sodium alumino silicates, titania, silica and rare earth elements. The accumulation of red-mud (or bauxite residue) in the world is 30 billion metric tons produced at a rate of 125 million tons per annum (2013). Utilization of red-mud for constructional purposes, wastewater treatment, metallurgical products, and pigments are listed. Metallurgical processing efforts of red-mud to generate various value added products such as pig iron, direct reduced iron slag wool, magnetite, titania, iron carbides are presented in the article.

Materials sustainability for environment: Red-mud treatment

Red-mud, the residue generated from the Bayers processing of bauxite ore in Jamaica was subjected to a low temperature reduction process. Hematite (~60 m%) was reduced to magnetite employing a gas based mixture of CO, CO2 and N2 as a diluent. Extensive thermodynamic study was conducted to identify the stability region for magnetite. ‘Optimal conditions’ for the gas-phase reduction were determined to be: a processing temperature of 540 °C ± 10 °C, partial pressures CO(g) and CO2(g) each of 0.070 atm (bar) ± 0.001 atm (bar)/inert diluent-gas: N2(g), for a conversion-time of 30 min. Mathematical model for reduction based on unidirectional diffusion is also formulated in this paper.

Low Temperature Reduction of Hematite in Red-Mud to Magnetite

The development of combined enrichment technologies becomes more significant due to the decreasing of the processed ores quality and involvement in the processing of poor, refractory ores. The difficulty in the flotation enrichment of mixed and oxidized polymetallic ores and intermediate products lies in the effective sulfidization of the surface of oxidized minerals. The sodium sulfide reagent used in flotation does not always provide complete sulfidization of the mineral surface. On the intermediate product of lead-zinc ores related to the phase composition of mixed ores, flotation studies were carried out on the original product and after preliminary sulfidization by the pyro-metallurgical method. It was found that in the pre-sulfidizied product, the extraction of zinc increased to 17.23 %, and lead to 10.07 %, compared with the original product without pre-treatment.

Sumedh Gostu

Papers

Materials sustainability for environment: Red-mud treatment

Low Temperature Reduction of Hematite in Red-Mud to Magnetite

Flotation studies of the middling product of lead-zinc ores with preliminary sulfidizing roasting of oxidized lead and zinc compounds