Evening star., 1951-12-14
Big Source of Uranium
Seen in Farm Fertilizer
Process Sought to Extract
Element in Phosphate Rock
BY Thomas R. Henry

Theoretically great untapped source
OF the now precious element uranium.
necessary basic material for any atomic
explosive or for atomic energy, is the
phosphate rock used in millions of tons
annually for fertilizer.
In much of this rock, analysis has
shown. there is from two to four tenths
of a pound of uranium per ton, says
Shelton P. Wimpfen of the Atomic
Energy Commissions raw materials di-
vision. About million tons of phos-
phate rock are processed annually by
the fertilizer industry.
Data on present uranium production
In the United States necessarily is re-
stricted and how much of the phosphate
rock contains an appreciable amount Of
the element is unknown. But even if
one-fourth of it would yield two-tenths
of pound per ton the resulting 35 tons
of uranium would be an appreciable
addition to amounts available.
The problem is to extract the uranium
by some process which will be economi-
cally feasible. Two methods are used in
fertilizer manufacture, the wet and dry
processes. In the former the method of
extracting the uranium now is clear
after extensive research carried out for
the commission at Massachusetts Tech,
the Battelle Memorial Institute and Dow
Chemical Co. laboratories. The uranium
in the rock is dissolved when the rock is
treated with an excess of sulphuric acid.
1t then can be recovered from the phos-
phoric acid which is formed.
DRY" Method of Recovery.
Dvy 81. 49,.
however, is treated by the so-called dry
process" in which the uranium recovery
is much more of problem. Several
possible methods have been studied by
commission scientists and one has been
found which separates the uranium with
reasonable efficiency. fairly large
pilot plant, built with the cooperation
of a major phosphoric acid producer,
now has been in operation for several
weeks and results to date have been
satisfactory. On the success of this
plant largely will depend any decision
on erecting full-scale plant
At the same time q full-scale pro-
duction plant now is in operation for
recovering uranium from the wet
process method used by one of the
Nations largest producers of phosphate
chemicals. The future is complicated
by lack Of knowledge as to the amounts
to be expected. 1t is known that the
large Florida phosphate rock deposits
contain respectable amounts Of the ele-
ment. So do some in the West. On the
other hand, the extensive Tennessee
phosphate beds contain, at the best,
only infinitesimal amounts of uranium.
hn ncfiY 0nf -
four-tenths of pound per ton is for
marine phosphate rocks-that is, beds
laid down under ancient seas. Possibly
the phosphate formations have had a
tendency to attract some of the vast
but unrecoVerable amounts of the ele-
ment present in sea water.
The source is bound to become more
important in the future Atomic Energy
Commission scientists believe, as more
and more fertilizer is required to keep
up the productivity Of American farms.
1t has been estimated that ct least a
million more tons of phosphates will be
required by 1860.
Not Beneficial to Plants.
At first there was some question as to
whether extraction of this uranium
might not be robbing Peter to pay Paul
that is, whether uranium itself might
not have definite value in fertilizer.
A series of experiments sponsored by
the commission apparently has estab-
lished that uranium is not a plant nu-
TRENT nor trace element in any way
beneficial to plant life. There is no
difference in the effectiveness of ferti-
lizer made from the Florida or Tennes-
see phosphate rock.
project demonstrating this, It is
announced, has been carried out by the
Agriculture Department in cooperation
with more than a dozen State expert
ment stations over two-year period.
No plant benefits whatsoever from the
uranium could be found.
The wet-proceSs method of extraction
apparently already is economically
feasible and several plants plan to in
stall uranium recovery facilities.
The uranium obtained from the
phosphates will, presumably, be the
same mixture of iSotopes as in any other
uranium. The super precious U-235,
the starting point for any atomic energy
process, will be found in ratio of one
atom per thousand.
II the various methods of extraction
from phosphates prove as feasible as is
indicated by the pilot-plan operations,
Atomic Energy Commission scientists
admit, the additions to the available
supply of the exploding element will be
appreciable.