碳酰胺助浸风化壳淋积型稀土矿工艺研究

Assisted Leaching Process of Weathered Crust Elution-Deposited Rare Earth Ore by Carbamide

研究了以碳酰胺为助浸剂的风化壳淋积型稀土矿浸取稀土工艺。通过柱浸方式模拟原地浸出过程,在单因素试验基础上,采用响应曲面法建立二次多项数学模型,以稀土浸取率为响应值,探究助浸剂碳酰胺浓度、浸取温度和浸取剂溶液pH对稀土浸取率的影响,分析各因素间的交互作用。结果表明,影响稀土浸取率从强到弱的因素依次是浸取剂溶液pH、碳酰胺浓度、浸取温度。在浸取剂乙酸铵浓度0.10 mol L条件下,最佳工艺参数为碳酰胺浓度0.59 mol/L、浸取温度25.03℃、浸取剂pH=5.51,该条件下稀土浸取率响应值为97.50%。实际试验稀土浸取率为96.36%。两者误差较小,表明采用响应曲面模型得到的工艺参数是基本可靠的。

Leaching of rare earth from weathered crust elution-deposited rare earth ore with carbamide as leaching aid was studied.In-situ leaching process was simulated by column leaching.Based on single factor experiment,a quadratic multinomial mathematical model was established by response surface method.Taking leaching rate of rare earth as the response value,effects of carbamide concentration,leaching temperature and pH value of leaching agent solution on rare earth leaching rate were investigated,and the interaction between the factors was analyzed.The results show that the sequence of factors affect leaching rate of rare earth from strong to weak is pH value of leaching agent solution,carbamide concentration,and leaching temperature.When ammonium acetate concentration is 0.10 mol/L,the response value of rare earth extraction rate is 97.50%under the optimum condition including carbamide concentration of 0.59 mol L,leaching temperature of 25.03℃,and pH value of leaching agent solution of 5.51.The actual experimental results show that the leaching rate of rare earth is 96.36%.The errors are small,which indicates that the process parameters obtained by response surface model is basically reliable.