Separation of Ga and Ge from leachate in zinc hydrometallurgy by modified peanut shells adsorption

The adsorption of Ga and Ge from zinc hydrometallurgy leachate by tartaric acid modified peanut shell was studied, with the effects of adsorption time, amount of modified peanut shell, initial pH value, adsorption temperature and initial concentration of Ga and Ge on the adsorption rate of Ga and Ge investigated and the kinetics of adsorption of Ga and Ge on peanut shell discussed. The results showed that the modified peanut shell could effectively separate Ga and Ge from zinc hydrometallurgy leachate, and the adsorption efficiencies of Ge were significantly higher than that of Ga. The adsorption of germanium was above 99% with initial pH of 3 at 30 ℃ within 3 h. The adsorption kinetics of Ga and Ge could be described by the pseudo-second-order model. The adsorption equilibrium of Ga and Ge by modified peanut shells was in accordance with Langmuir model. According to Langmuir equation, the maximum adsorption capacities of modified peanut shells for Ga and Ge were respectively 2.77 and 3.03 mg/g. The modified peanut shells that have adsorbed Ga and Ge could be desorbed and regenerated with H₂SO₄ solution, and then recycled.