有机酸对低品位磷矿粉的活化及释磷动力学研究

Activation and phosphorus releasing kinetics of low-grade powdered phosphate rock by organic acids

研究了相同浓度下多种有机酸对低品位磷矿粉的活化效果,结果表明,在40mmol/L浓度下,草酸的活化效果最好,溶液中的可溶性磷质量浓度达到了187.5mg/L。进一步研究了草酸活化低品位磷矿粉的工艺参数优化,结果表明,在浓度为20mmol/L,温度为20℃,固液比为3∶500时,反应48h可溶性磷质量浓度最佳。选取一级动力学方程、Elovich方程和抛物线方程进行拟合,结果表明草酸活化低品位磷矿粉的过程较符合一级动力学方程。

Activation of the low-grade powdered phosphate rock by various organic acids at the similar concentration was studied.The results showed that oxalic acid had the best activation effect on the low-grade powdered phosphate rock at 40mmol/L with the content of soluble phosphorus in the solution up to 187.5 mg/L.Optimization of the process parameters for activation of the lowgrade powdered phosphate rock by oxalic acid was further studied.The results showed that the best concentration of soluble phosphorus released by oxalic acid was obtained at the conditions of acid 20 mmol/L,temperature 20 ℃,solid-to-liquid ratio 3∶50and reaction time 48 h.The fitting of first-order equation,Elovich equation and parabolic equation indicated that the process for activation of the low-grade powered phosphate rock by oxalic acid was consistent with the first-order kinetic equation.