Hydrogen generation through water splitting reaction using waste aluminum in presence of gallium

Highly efficient and stable PEI@Al2O3 adsorbents derived from coal fly ash for biogas upgrading

A cleaner electrolysis process to recover alumina from synthetic sulfuric acid leachate of coal fly ash

Clean production of porous-Al(OH)3 from fly ash.

The global market of lithium-ion batteries (LIB) has been growing in recent years, mainly owed to electromobility The global LIB market is forecasted to amount to $1293 billion in 2027 Considering the global reserves needed to produce these batteries and their limited lifetime, efficient recycling processes for secondary sources are mandatory A selective process for Li recycling from LIB black mass is described Depending on the process parameters Li was recovered almost quantitatively by the COOL-Process making use of the selective leaching properties of supercritical CO2/water Optimization of this direct carbonization process was carried out by a design of experiments (DOE) using a 33 Box-Behnken design Optimal reaction conditions were 230 °C, 4 h, and a water:black mass ratio of 90 mL/g, yielding 986 ± 019 wt% Li Almost quantitative yield (9905 ± 064 wt%), yet at the expense of higher energy consumption, was obtained with 230 °C, 4 h, and a water:black mass ratio of 120 mL/g Mainly Li and Al were mobilized, which allows for selectively precipitating Li2CO3 in battery grade-quality (>998 wt%) without the need for further refining Valuable metals, such as Co, Cu, Fe, Ni, and Mn, remained in the solid residue (977 wt%), from where they are recovered by established processes Housing materials were separated mechanically, thus recycling LIB without residues This holistic zero waste-approach allows for recovering the critical raw material Li from both primary and secondary sources

https://www.mdpi.com/2075-4701/11/2/259/pdf

The COOL-Process—A Selective Approach for Recycling Lithium Batteries

Aluminum hydroxide crystallization from aluminate solution using carbon dioxide gas: Effect of temperature and time

Bayerite is one of the phases of aluminum hydroxide which is precipitated by the carbonation of aluminate solutions obtained from sintered nepheline syenite leaching. In this study, the conditions for the bayerite formation were predicted by thermodynamic modeling of the carbonation process and the Bromley- Zemaitis model was used for this purpose. Carbonation experiments were carried out at pH 11 and the temperature range of 50- 90 °C based on the data obtained from thermodynamic modeling results. XRD analysis of products showed that bayerite was the predominant phase at all temperatures. SEM and LDS analysis indicated that the bayerite precipitates had uniform morphology and bimodal particle size distribution with mean particle size of 4.6 μm at 50 °C to 12.9 μm at 90 °C. It was found that the d50 increased slowly at the precipitation temperature ranging from 80 to 90 °C, from 12.6 to 12.9 μm and the effect of temperature was on the shape of particles. XRF analysis of the products indicated that the amount of Al2O3 and SiO2 in the bayerites decrease by increasing the temperature. According to the thermodynamic modeling data and experimental results, the temperature of 80 °C and pH 11 were determined as optimal conditions for bayerite precipitation.

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Thermodynamic Modeling and Experimental Studies of Bayerite Precipitation from Aluminate Solution: Temperature and pH Effect

The effect of pH and seeding were studied on phase, particle size, morphology, purity and conversion of aluminum hydroxide produced by carbonation of solution of sintered nepheline syenite alkaline...

Aluminum hydroxide crystallization from aluminate solution using carbon dioxide gas: effect of pH and seeding

The purpose of this study is to develop the kinetic model and to find the optimum leaching conditions for maximum alumina dissolution from sintered nepheline syenite resource in the alkaline solution. About 80% of alumina (smaller than 5% of silica) was effectively recovered at 80 °C, 3 M NaOH, particle size less than 88 μm, agitation speed of 800 rpm, and leaching time of 60 min with a minimum amount of silica dissolution. Based on the kinetic model and the obtained reaction degree of each effective parameter, the experimental data were simulated. The simulation results proved that the leaching process for alumina was controlled by diffusion through the solid product layer and reaction at the interface of unreacted core that was confirmed by the value of activation energy (15.53 kJ/mol). The provided optimum conditions could be effective to decrease the silica dissolution, and to improve the alumina recovery.

Kinetics Studies of Sintered Nepheline Syenite Alkaline Leaching under Atmospheric Pressure

The polythermal crystallization method has been used to extract sodium and potassium carbonate salts as valuable by-products. The salt production was carried out using an alkaline carbonate solutio...

Somayeh Shayanfar

Papers

Aluminum hydroxide crystallization from aluminate solution using carbon dioxide gas: Effect of temperature and time

Thermodynamic Modeling and Experimental Studies of Bayerite Precipitation from Aluminate Solution: Temperature and pH Effect

Aluminum hydroxide crystallization from aluminate solution using carbon dioxide gas: effect of pH and seeding

Kinetics Studies of Sintered Nepheline Syenite Alkaline Leaching under Atmospheric Pressure

Production and characterisation of sodium and potassium carbonate salts from carbonation alkaline aluminate liquor