Removal of cadmium and arsenic from Cd-As-Pb-bearing dust based on peroxide leaching and coprecipitation

Release time:2023-01-07

Impact Factor:4.217

DOI number:10.1016/j.hydromet.2022.105839

Journal:Hydrometallurgy

Key Words:Arsenic, Cadmium, Lead dust, Coprecipitation, Separation

Abstract:As a byproduct of lead metallurgy, Cd-As-Pb-bearing dust, is a hazardous waste. This paper proposes a coprecipitation method for Cd and As removal and applies it to dust disposition. First, a thermodynamic analysis of the Cd2+-AsO43− -H2O system was conducted, and the predominant areas of solid phase, including Cd5H2(AsO4)4, Cd3(AsO4)2 and Cd(OH)2, were obtained at different molar ratios of cadmium to arsenic (nCd/nAs). Second, the effects of nCd/nAs ratio and pH on the precipitation behaviors of Cd and As were examined. The precipitated solids varied from Cd5H2(AsO4)4•4H2O to Cd3(AsO4)2•4H2O and then to amorphous Cd(OH)2 with increasing pH. The morphology of solids transformed from cuboid to flake particles and then to fine agglomerated particles. Perfect removal of Cd and As can be achieved by generating Cd5H2(AsO4)4•4H2O with molar ratios of nCd/nAs 1.25 at pH 5.5 or Cd3(AsO4)2•4H2O with nCd/nAs 1.50 at pH 7.5. Finally, a method of H2O-H2O2 leaching and Cd-As coprecipitation was proposed to treat Cd-As-Pb-bearing dust. The precipitation efficiencies of Cd and As were higher than 99.7%. This work improved a one-step method for removing toxic Cd and As from polymetallic dust and other materials.

Indexed by:Journal paper

Discipline:Engineering

First-Level Discipline:Metallurgical Engineering

Document Type:J

Volume:209

Page Number:105839

Translation or Not:no

Date of Publication:2022-02-17

Included Journals:SCI