Preparation and adsorption characteristics for heavy metals of active silicon adsorbent from leaching residue of lead-zinc tailings

Abstract

To comprehensively reuse the leaching residue obtained from lead-zinc tailings, an active silicon adsorbent (ASA) was prepared from leaching residue and studied as an adsorbent for copper(II), lead(II), zinc(II), and cadmium(II) in this paper. The ASA was prepared by roasting the leaching residue with either a NaCO/residue ratio of 0.6:1 at 700 °C for 1 h or a CaCO/residue ratio of 0.8:1 at 800 °C for 1 h. Under these conditions, the available SiO content of the ASA was more than 20%. The adsorption behaviors of the metal ions onto the ASA were investigated and the Langmuir, Freundlich, and Dubinin-Radushkevich isotherm models were used to analyze the adsorption isotherm. The result showed that the maximum adsorption capacities of copper(II), lead(II), cadmium(II), and zinc(II) calculated by the Langmuir model were 3.40, 2.83, 0.66, and 0.62 mmol g, respectively. The FT-IR spectra of the ASA and the mean free adsorption energies indicated that ion exchange was the mechanism of copper(II), lead(II), and cadmium(II) adsorption and that chemical reaction was the mechanism of zinc(II) adsorption. These results provide a method for reusing the leaching residue obtained from lead-zinc tailings and show that the ASA is an effective adsorbent for heavy metal pollution remediation.

Characterization of the Adsorption of Cu (II) from Aqueous Solutions onto Pyrolytic Sludge-Derived Adsorbents

“…The disordering of silicate in Cu MS causes the overlap of the different absorption bands, which broaden the absorption band. Furthermore, the adsorption of the Cu would promote by the monosilicate [27].…”

A Functionalized Silicate Adsorbent and Exploration of Its Adsorption Mechanism

“…The newly developed Si-O stretching vibration peak at 589 cm −1 indicated that the SiO 2 network had been damaged [25]. The wide peak of the adsorbent at 1000-1100 cm −1 was attributed to the breaking of the mesh structure of quartz during heating to form disordered SiO 4 [14]. The tensile peak at 887 cm −1 was attributed to Si-O-Na [26].…”

“…Our team used leaching residue from lead-zinc tailings with high silicon content as a raw material to prepare an active silicate heavy metal adsorbent, which showed a very high adsorption capacity for the heavy metals Cu, Pb, Cd and Zn. The saturated adsorption capacities were 3.40, 2.83, 0.66 and 0.62 mmol/g, respectively [14].…”

“…Our team used leaching residue from lead-zinc tailings with high silicon content as a raw material to prepare an active silicate heavy metal adsorbent, which showed a very high adsorption capacity for the heavy metals Cu, Pb, Cd and Zn. The saturated adsorption capacities were 3.40, 2.83, 0.66 and 0.62 mmol/g, respectively [14].Besides, when active silicate materials are applied to the remediation of heavy metals in soil, extractable heavy metals can be transformed into forms with relatively stable valence [15,16], and the heavy metal stress and accumulation in plants can be reduced [17]. Moreover, the active silicates can be absorbed by plants as nutrient elements to form phytoliths, which play an important role in increasing grain yield and enhancing photosynthesis, pest resistance, lodging resistance, and so on [18,19].At present, most of the active silicate materials are solid wastes, such as steel slag, fly ash, tailings and so on [20,21].…”

Mechanical Properties and Toxicity Risks of Lead-Zinc Sulfide Tailing-Based Construction Materials

“…Metals could be recycled from the tailings with separation and intensive leaching process. While, after metals recovery from Lead–Zinc Sulfide Tailings, a large amount of leaching residue of Lead–Zinc Sulfide Tailings (LRT) will be produced [ 1 ], and little attention has been paid to its disposal so far. The LRT output was varied based upon the different leaching recovery procedures [ 2 , 3 ], and its storage was stint by its acidity and the heavy metals.…”