Recovery of Arsenic from Arsenic-Containing Sulfide Residue by Sulfur Acid-Hydrogen Peroxide Leaching

Graphical Sulfuric acid - hydrogen peroxide is used to leach containing-arsenic sulfide residue under the atmospheric pressure and mild temperature. Key factors of influencing the leaching process are investigated. Leaching rate for As is 98.42%. Arsenic(V) of leaching solution is reduced by SO 2 to obtain As 2 O 3 . The overall recovery rate of As throughout the entire process is 90.67%, thereby enabling the recovery of arsenic. Arsenic-containing sulfide residue from copper smelting is a kind of dangerous solid waste. However, the residue is also a recycling resource due to its numerous valuable components. Sulfuric acid-hydrogen peroxide was used to leach containing-arsenic sulfide residue, followed by the recovery of arsenic (As). The effects of temperature, dosage of hydrogen peroxide, the concentration of sulfuric acid, particle size, and solid-to-liquid ratio on sulfuric acid-hydrogen peroxide leaching were investigated. The results show that the optimal leaching conditions were leaching time of 120 min, the temperature of 60 °C, H 2 O 2 dosage of 1 mL/g, H 2 SO 4 concentration of 200 g/L, particle size of 200 mesh, and solid-to- liquid ratio of 1:4. Leaching rates for As and Cu were 98.42% and 97.57%, with As and Cu concentrations of 38.2 and 3.73 g/L in the leaching solution, respectively. During the reduction of As(V) using SO 2 in the leaching solution, the optimal conditions were SO 2 flow rate of 60 mL/min, reaction temperature of 10 °C, and reaction time of 2 h. The reduction efficiency of As(V) reached 95.75%, with the purity of As 2 O 3 achieving 98.71%. The overall recovery rate of As throughout the entire process was 90.67%.