硝磷酸法合成磷酸铁新工艺因生产流程简单、磷源成本低、设备投资小、能耗较低、绿色环保而具有很强的竞争力。利用FactSage和HSC等热力学软件中已有的热力学数据并运用E-pH图的绘制原理,得到Fe-P-N-H₂O体系不同浓度、298~473 K的E-pH关系图。研究表明,在水溶液中,磷酸铁具有较大的热力学稳定区域,能够很好地解释现有的液相沉淀法制备磷酸铁的实际操作条件。此外,从E-pH图中获得了共沉淀法合成磷酸铁的合适条件:温度为363 K左右、高氧化还原电位为 0.5 V、适宜pH为1~3、浓度为0.01 mol/L,该工艺为硝磷酸体系共沉淀法合成磷酸铁提供了热力学理论依据。

The new process for synthesizing ferric phosphate via the nitro-phosphoric acid method presents strong competitiveness due to its simple production process,low cost of phosphorus sources,small equipment investment,lower energy consumption,and environmentally friendly characteristics.E-pH relationship diagram is established for Fe-P-N-H₂O system at various concentrations in 298-473 K through utilizing thermodynamic data available in software such as FactSage and HSC,and applying the constructing principles of E-pH diagrams.Research indicates that ferric phosphate has a large thermodynamically stable region in aqueous solution,which explains well the practical conditions of the existing liquid phase precipitation method for preparing ferric phosphate.Furthermore,suitable conditions for the co-precipitation synthesis of ferric phosphate obtained from E-pH relationship diagram are as follows:a temperature around 363 K,a high oxidation-reduction potential of 0.5 V,an optimal pH of 1 to 3,and a concentration of 0.01 mol·L^-1.This process provides a thermodynamic theoretical basis for the synthesis of ferric phosphate by co-precipitation in the nitro-phosphoric acid system.

谷任权(1999-),男,硕士生,研究方向为磷化工与资源利用,18274757313@163.com;杨秀山(1984-),男,博士,副教授,研究方向为磷化工与资源利用,通讯联系人,yangxiushan3@163.com。