Title of Research Project
: ‘Solvent extraction of refractory metals
with N-n-octylcyclohexylamine’
UGC Reference No.
: File No. 47-1975/11 (WRO) dated 21
Feb. 2012
Name of the Principal Investigator
: Dr. Sandip Vinayak Mahamuni
Department
: Chemistry
College where work has progressed
: Sadguru Gadage Maharaj College, Karad
Tal. Karad, Dist. Satara, Maharashtra
Pin - 415124
Executive summary of the Project
Molybdenum is mainly employed as a hardening agent in alloys. Molybdenum is
used in a variety of electronic devices, comprising tubes, contacts, electrodes, transducers,
transistors and rectifiers. Molybdenum containing metals are important catalysts and also
as activators and promoters of other catalysts in many petroleum and organic chemical
reactions. Molybdenum is important in the life processes of plants and animal. Tungsten
when added to iron or steel, improves high temperature strength and hardness. High
density tungsten-copper-nickel alloys have been utilized for radiation shielding. Tungsten
is one of the best hard tool materials, retaining its properties at elevated temperatures. The
most pervasive use of tungsten is as the filaments in incandescent lamps. The tungsten
compounds may function as principal catalysts or promoters of other catalysts.
There is need for simple and rapid method for the determination of molybdenum
and tungsten. We have satisfactorily developed new solvent extraction methods for these
metals at trace level.
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In the present work, we prepared a high molecular weight secondary amine
extractant, N-n-octylcyclohexyl amine. The extractant N-n-octylcyclohexylamine was
characterized by studying its NMR and GC-MS spectra. It was then explored for
extraction of molybdenum and tungsten. The effect of acidity, extractant and metal
concentration, solvents, equilibrium time, aqueous to organic volume ratio, strippants
were studied critically to establish optimum conditions to achieve quantitative extraction
of molybdenum and tungsten. The extraction of molybdenum(VI) was found to be
quantitative with 0.05 M N-n-octylcyclohexylamine in dichloromethane and xylene (1:4)
from 1.5 M hydrochloric acid. The strippant used was three 10 mL portions of 1 M
ammonia solution. Molybdenum(VI) was estimated by thiocyanate method. The
tungsten(VI) was quantitatively extracted with 0.05 M N-n-octylcyclohexyl amine in
dichloromethane and xylene (1:4) from 0.1 M hydrochloric acid. Tungsten(VI) from
organic phase was backextracted with two 10 mL portions of 1 M ammonia solution.
Tungston(VI) was estimated by thiocyanate method.
Dr. Sandip V. Mahamuni
(Principal Investigator)
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