What question did this study set out to answer?

The research aims to explore the effectiveness of iron tailings in creating ceramsite for the removal of cadmium (Cd(II)).

May 28, 2026BMC Chemistry0 citationsOpen Access

Preparation and performance of iron tailings based porous ceramsite material for Cd(II) adsorption: evidence of the dominant action mechanism

SHShaoguang HuaUniversity of Science and Technology of China DPDejian PeiMasteel (China)HZHuihui ZhouUniversity of Science and Technology of China

Key Points

The research aims to explore the effectiveness of iron tailings in creating ceramsite for the removal of cadmium (Cd(II)).
Investigated various preparation processes for ceramsite using iron tailings.
Characterized the ceramsite using XRD, DSC, BET, SEM–EDS, and XPS to assess its properties.
Conducted Cd(II) adsorption tests to evaluate kinetics and isotherm behavior.
Ceramsite sample No. 3 achieved 80.79% Cd(II) removal in 2 hours and 95.57% in 21 hours.
Adsorption followed pseudo-second-order kinetics with a Langmuir isotherm, indicating a predominance of chemisorption.
The high specific surface area (2.1 m2/g) supported efficient physical adsorption through its pore structure.

Abstract

This study investigated the feasibility of preparing ceramsite from iron tailings for cadmium (Cd(II)) adsorption. Based on Si-Ca ceramsite compositional design, the Cd(II) adsorption mechanism of ceramsite fired in different preparation process were studied. The Cd(II) adsorption properties and pore structure were detected, and the phase composition and crystal morphology were investigated using XRD, DSC, BET, SEM–EDS and XPS. Results demonstrated that: the ceramsite sample No. 3 (fired at 1150 °C for 30 min) formed akermanite, gehlenite, and diopside phases. It achieved fast adsorption kinetics (80.79% removal in 2 h) and high equilibrium capacity (95.57% removal in 21 h) for Cd(II), with confirmed environmental safety. Adsorption followed pseudo-second-order kinetics and the Langmuir isotherm, indicating combined various processes dominated by chemisorption. The small aperture size (5.19 μm) and high specific surface area (2.1 m2/g) supported physical adsorption. The high-valent sulfur was reduced to S2− in preparation process for CdS chemical precipitation. The Cd(II) adsorption of the ceramsite sample No. 1-A through pore structure was mainly physical adsorption. The Cd(II) adsorption capacity of the ceramsite sample No. 1-I was deteriorated due to the change of pore structure caused by formation of forsterite ferroan. This work successfully repurposed iron tailings as a functional adsorption component, especially offering a novel strategy for valorizing high-sulfur iron tailings alongside other solid wastes.

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