从FCC烟气脱硫污泥中提取稀土试验研究

Research on Recovery of Rare Earth From FCC Flue Gas Desulfurization Slag

研究了采用高温酸解法和蒸发浓缩法从FCC装置产生的脱硫污泥中分离提取稀土,考察了不同酸解条件和分离条件对稀土浸出率和沉淀率的影响,采用X射线粉末衍射仪(XRD)和X荧光光谱仪(XRF)对得到的稀土化合物进行表征。结果表明:污泥最佳酸解条件为反应温度120℃,反应酸浓度60%,反应时间3h;最佳分离浓缩比为1/5,分离率达95.12%;产品为硫酸稀土复盐,晶型完整,高纯无杂晶。该方法可用于从FCC烟气脱硫污泥中分离提取稀土,对减少稀土资源浪费具有重要意义。

Recovery of rare earth from the slag coming from FCC flue gas desulfurization system by a high-temperature acidolysis and concentrated-filtration was researched. The effects of different acidolysis and separation conditions on recovery of rare earth were examined. The rare earth compound was characterized by X-ray powder diffraction （XRD） and X-ray fluorescence spectrometer（XRF）. The results show that the best acidolysis conditions are reaction temperature of 120 ℃, reaction acid concentration of 8 mol/L, reaction time of 3 h. And the optimal concentrating ratio is 1/5, the precipitation rate of the rare earth is up to 95. 12%. The chemical composition and phase of the precipitate are both the rare earth-sodium sulfate double salt with perfect crystal and high purity. The rare earth in the sludge can be successfully recovered which could reduce rare earth elements waste and help great promise in environment protection.