(中南大學(xué) 冶金與環(huán)境學(xué)院，長沙 410083)
摘 要: 采用共沉淀法制備新型的含Al、Ca復(fù)合除氟劑。結(jié)果表明:在含100 g/L Zn2+、160 g/L H2SO4和450 mg/L F-的硫酸鋅電解液中復(fù)合除氟劑除氟的最優(yōu)條件為:pH=3，t=90 min，w=4 g/L，θ=25 ℃。此時，F(xiàn)-濃度可降低至20 mg/L以下，除氟率可達(dá)96%，除氟劑吸附容量達(dá)108 mg/g。結(jié)果表明:僅當(dāng)Cl-濃度大于800 mg/L時，復(fù)合除氟劑的除氟率降至93%。SO42-和Zn2+的濃度對復(fù)合除氟劑的除氟效果沒有影響，除氟率一直保持在96%左右，除氟過程鋅損失率小于5%。吸附平衡曲線結(jié)果表明:該型復(fù)合除氟劑的吸附過程符合Langmuir 單層吸附模型，最大理論吸附容量143.3 mg/g。
關(guān)鍵字: 鋅電積;硫酸鋅;除氟;Langmuir 單層吸附模型
（School of Metallurgy and Environment, Central South University, Changsha 410083, China）
Abstract:A novel Al, Ca-containning composite defluoridation agent was synthetized by co-precipitation method. The results show that the optimum conditions to defluoridation from zinc sulfate solution (ρ(F-)=450 mg/L, ρ(H2SO4)=160 g/L, ρ(Zn)=60 g/L) are as follows:pH=3, t=90 min, w=4 g/L, θ=25 ℃. The final ρ(F-) is below 20 mg/L, the fluoride ions removal efficiency is about 96%, and the adsorption capacity is 108 mg/g. The results show that only when the ρ(Cl-) is above 800 mg/L, the fluoride removal efficiency slightly descends to 93%. The ρ(SO42-) and ρ(Zn2+) show no influence on the removal efficiency, zinc loss rate is less than 5% during the defluoridation process. The equilibrium isotherm reasonably fits the Langmuir isotherm model, and the maximum monolayer sorption capacity is 143.3 mg/g.
Key words: zinc electrowinning; zinc sulfate; defluoridation; Langmuir isotherm model
