Using One-Step Acid Leaching for the Recovering of Coal Gasification Fine Slag as Functional Adsorbents: Preparation...

Area of Science:

• Materials Science
• Environmental Chemistry
• Chemical Engineering

Background:

• Coal gasification fine slag (FS) is a significant industrial by-product requiring sustainable management.
• Developing functional adsorbents from waste materials addresses environmental concerns and resource recovery.

Purpose of the Study:

• To prepare functional adsorbents from coal gasification fine slag (FS) via an optimized acid leaching process.
• To evaluate the adsorption performance of the synthesized materials for Methylene Blue (MB) removal.
• To explore a cost-effective strategy for FS disposal and value addition in the coal chemical industry.

Main Methods:

• Orthogonal optimization of acid leaching using various acids (HCl, HNO3, HF, HAc, H2SO4).
• Adsorption performance evaluation using Methylene Blue (MB) as a model pollutant.
• Characterization of adsorbents using XRD, SEM, FTIR, and BET surface area analysis.
• Adsorption mechanism investigation using pseudo-second-order, Langmuir models, and thermodynamic analysis.

Main Results:

• Optimal conditions (2.0 mol/L HNO3, 2.0 h, 293K) yielded a leaching efficiency of 57.6% and an MB adsorption capacity of 162.94 mg/g.
• Characterization confirmed the synthesis of mesoporous functional adsorbents.
• Chemisorption, pseudo-second-order kinetics, and Langmuir isotherm models best described the MB adsorption process.
• Thermodynamic studies indicated a spontaneous and exothermic adsorption process.

Conclusions:

• Acid leaching is an effective method for transforming coal gasification fine slag into high-performance adsorbents.
• The synthesized mesoporous materials demonstrate significant potential for Methylene Blue removal.
• This approach offers a novel, cost-effective strategy for industrial waste valorization and environmental remediation.