This study addresses the liquid-liquid extraction behavior of phosphorus from a sulfuric acid solution using benzyl dimethyl amine (BDMA) in kerosene. The extraction equilibria investigated with varied BDMA concentrations could reveal the formation of \(\overline {3[{\rm<Emphasis Type="Bold">MA</Emphasis>}] \cdot [{{\rm{H}}_3}{\rm{P}}{{\rm{O}}_4}]} \) complex in the organic phase. The thermodynamic properties determined at various temperatures indicated that the process was exothermic with a calculated enthalpy (ΔH^⊖) of −24.0 kJ·mol⁻¹. The organic-to-aqueous phase (O/A) volume ratio was varied to elucidate the quantitative extraction of phosphorus. The McCabe-Thiele diagram plotted for the extraction isotherm was validated for the requirement of three counter-current stages in the extraction at an O/A volume ratio of 2.0/3.5. The back-extraction of phosphorus from the loaded organic phase was quantitatively achieved by contacting 4.0 mol·L⁻¹ H₂SO₄ solution in three stages of counter-current contact at an O/A volume ratio of 3/2. This study can be applied to remove phosphorus from the sulfuric acid leach solutions of monazite processing, and many other solutions.

这项研究解决了在煤油中使用苄基二甲基胺（BDMA）从硫酸溶液中磷的液-液萃取行为。用不同的BDMA浓度研究的萃取平衡可以揭示\（\ overline {3 [{\ rm <Emphasis Type =“ Bold”> MA </ Emphasis>}] \ cdot [{{\ rm {H}} _ 3 } {\ rm {P}} {{\ rm {O}} _ 4}]} \）有机相中的络合物。在各种温度下测定的热力学性质表明，该过程是放热的与计算出的焓（Δ ħ ^⊖的-24.0千焦）·摩尔^-1。改变有机相与水相（O / A）的体积比，以阐明磷的定量提取。为提取等温线绘制的McCabe-Thiele图经验证，在O / A体积比为2.0 / 3.5的情况下，在提取中需要三个逆流阶段。通过在三个阶段的逆流接触中以3/2的O / A比例接触4.0mol·L ^-1 H ₂ SO ₄溶液，定量地从负载的有机相中反萃取磷。该研究可用于从独居石加工的硫酸浸出溶液和许多其他溶液中去除磷。