Minimum Amount of Extracting Solvent of (A_(1)A_(2)…A_(t−1))/(A_(2)A_(3)…A_(t)) Separation When Using Non-barren Extracting Solvent

Hyperlink extraction technology,by virtue of its remarkable advantage of decreasing the use of chemicals in multi-component separation,has been extensively employed in rare earth separation industry in China.In hyperlink processes,non-barren extracting solvent and scrubbing agent solution which contain the component(s)involved in starting feed are employed in order to save both alkali for saponification and acid for scrubbing.Minimum amount of extracting solvent(denoted as S_(min))and that of scrubbing agent solution(denoted as W_(min))are important parameters to determine the consumption amounts of alkali and acid for a given countercurrent extraction separation.This article therefore discusses the influence of using non-barren extracting solvent and scrubbing agent solution on S_(min) and W_(min) of an(A_(1)A_(2)…A_(t−1))/(A_(2)A_(3)…A_(t))separation.The equations for S_(min) and W_(min) are derived,and the variation of the composition of final raffinate as well as that of final extract are determined,which will provide a valuable guidance for the design of hyperlink extraction processes of multi-component separation,such as rare earths separation.