TITLE:
Minimum Amounts of Extracting Solvent of (A1A2···At-1)/(A2A3···At) Countercurrent Extraction Separation
AUTHORS:
Fu-Xiang Cheng, Sheng Wu, Song-Ling Wang, Bo Zhang, Yan Liu, Chun-Sheng Liao, Chun-Hua Yan
KEYWORDS:
Theory of Countercurrent Extraction, Minimum Amount of Extracting Solvent, Countercurrent Extraction, Hyperlink Process, Multi-Component Separation
JOURNAL NAME:
Advances in Materials Physics and Chemistry,
Vol.5 No.8,
August
21,
2015
ABSTRACT: Minimum
amounts of extracting solvent and scrubbing agent solution (denoted as Smin and Wmin respectively) mean the theoretical minimal requirements
for chemicals to achieve a specified separation duty, and therefore attract more
concerns in the process design of countercurrent extraction separation. Over the
past decade, hyperlink extraction technology has been widely used in rare earth
separation industry in China with the target to decrease chemical consumption as
well as pollution discharges. However, the equations of Smin and Wmin derived in the earlier version of the theory of countercurrent extraction can only
be correctly applied to two-component separation and become invalid for hyperlink
processes. It is significant to develop new aspects of the theory for design of
the hyperlink processes. The separation of (A1A2···At－1)/(A2A3···At) is the basic configuration
in the hyperlink processes differently from in conventional processes, where A1,
A2, ···, At represent
different kinds of rare earth ions with the same number of valence. The separations
of two and three components have been discussed and the equations of Smin and Wmin are derived in our previous works. Nevertheless, it
is still significant, especially for rare earth separations, to investigate the
separations with more components. The present article will therefore focus on developing
new expressions for Smin and Wmin applied to the (A1A2···At﹣1)/(A2A3···At) separation. Also a five-component
separation case is simulated according to the derived equations. This work is an
essential part of the new theory to design the hyperlink extraction processes.