Chemicals Based
Technologies - Manufacture of Di (2-Ethyl Hexyl)
Phosphoric Acid
Introduction
In the world
scenario of extraction metallurgy of nuclear, refractory,
based and precious metals, solvent extraction is a proven
commercial technique for the purification and concentration
of various leach liquors. At present this technique
is being practised for large scale production of high
purity metals like uranium, zirconium, hafnium, niobium,
tantalum and rare earths. A beginning has been made
to use this technique for the recovery of base metals
such as Copper, Nickel, Cobalt and Zinc from various
secondary resources.
Among the various classes of organic
solvents di(2-ethyl hexyl) phosphoric acid (D2EHPA)
has emerged as a popular acidic extractant for the recovery
of uranium from phosphoric acid, rare earths from mixed
rare earth chlorides and Copper/Nickel/Cobalt/Zinc from
sulphate solutions. The product (D2EHPA) has a purity
~ 95% with a monoester content of less than 2%. The
overall yield based on PCL3 is 90%. The process of manufacture
consists of following steps.
Reaction of alcohol with PCL3 to
form diphosphite
Its oxidation by cholrination
Hydrolysis of the chloridate
to technical grade D2EHPA
For further information please contact
:
Head,
Technology Transfer & Collaboration Division,
Bhabha Atomic Research Centre, Trombay,
Mumbai - 400 085
Tel : 091-022-25505337/25593897
Fax : 091-022-25505151
E-mail : headttcd@barc.gov.in
