AN IMPROVED MODE OF OR PROCESS FOR OBTAINING FERTILIZING SUB- " STANCES
Year: 1873

page_text: LETTERS PATENT to Henry Young Darracott Scott, of Ealing, in tho
County of Middlesex, Major-General, C.B., for the Invention of
"AN IMPROVED MODE OF OR PROCESS FOR OBTAINING FERTILIZING SUB-
"
STANCES."
Sealed the 15th July 1873, and dated the 25th January 1873.
PROVISIONAL SPECIFICATION left by the said Henry Young Darracott
Scott at the Office of the Commissioners of Patents, with his Petition,
on the 25th January 1873.
I; HENRY YOUNG DARRACOTT SCOTT, of Ealing, in the County of
Middlesex, Major-General, C.B., do hereby declare the nature of the
said Invention for "AN IMPROVED MODE OF OR PROCESS FOR OBTAINING
FERTILIZING SUBSTANCES," to be as follows:-
The object of this Invention is the manufacture of precipitated
phosphates by the addition to clarified sewage water of impure
phosphatic substances, such as coprolites dissolved in acid.

page_text: In carrying out my Invention I first remove from the sewage water
all the suspended matters by precipitation; and I prefer to use lime
alone for this purpose. I add the lime in sufficient quantity to leave free
lime in solution after all the matters admitting of precipitation by this
chemical have been removed.
Should sulphate of alumina and iron be employed for this preliminary
precipitation in combination with lime, I so arrange that the lime
shall always be in excess. The precipitate thus obtained is allowed to
subside in a tank, which I will call tank No. 1, and may be dealt with
by methods already known, such as converting it into agricultural lime
or cement, or into charcoal to be used in the final purification of the
effluent, which will be clarified very effectually by the excess of line
used. The excess of lime will also render the deposit very inoffensive.
The effluent from tank No. 1 is now treated with a solution which is
prepared by digesting by well known methods, impure phosphatic
substances, such as coprolites in acid, and decanting the liquid obtained
from the intractable residuc. The precipitate thus formed (by the
reaction between the free lime in the sewage and the phosphoric acid in
the solution added) is allowed to settle in tank No. 2, and from this
tank it is removed at intervals, dried and sent into the market as
precipitated phosphate. Such phosphate having been freed from the
greater portion of the substances, as fertilizers, existing in the original
material, which are inert, and having been freed also from the adulterations
of worthless sewage matters, will be found to have a very high com-
mercial value as compared with the sewage precipitated phosphates
hitherto sent into the market, wherewith all the suspended impurities of
the sewage, together with much mineral matter precipitated from
solution have been mixed up.
The solution of the phosphatic substances may be added to the
effluent from tank No. 1, either in quantities which leave it still alkaline,
or the solution may be added in slight excess. By the latter mode of
treatment the precipitate in tank No. 2 will be freer from the less
valuable substances, but portions of the fertilizing ingredients will be
carried away in the effluent from tank 2, and aro to be detained
by precipitation with lime in sufficient quantity to make the
sewage water alkaline in tank No. 3. The precipitate thus obtained
may be sold as another quality of phosphate, or may be mixed with

page_text: the agricultural lime prepared by calcination from the deposit in
tank No. 1.
The effluent from the above processes may be finally freed from organic
matter by filtration through charcoal, which may be obtained by
charring the precipitate obtained from tank No. 1. After such char-
coal becomes clogged with impurities it may likewise be added to the
agricultural lime obtained from other portions of the deposit in the same
tank, or it may be sold independently.
I sometimes add finely divided mineral phosphates to the sewage
water (with the milk of lime) for the first precipitation in tank No. 1.
The calcined residue may have its free lime washed out with clarified
sewage water, which may be employed for the precipitation of a fresh
quantity of sewage, whilst the undissolved residue may be treated with
hydrocholic acid, and the compound be used to cause. the precipitation
of phosphates and silicic acid in tank No. 2, as under such conditions
the silicic acid will remove ammonia and nitrogenous matter from
solution.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Henry Young Darracott Scott in the Great Seal
Patent Office on the 25th July 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
YOUNG DARRACOTT SCOTT, of Ealing, in the County of Middlesex,
Major General, C.B., send grecting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, hearing date the Twenty-fifth day of January, in the
year of our Lord One thousand eight hundred and seventy-three, in
the thirty-sixth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Henry Young Darracott Scott,
Her special licence that I, the said Henry Young Darracott Scott, mý
executors, administrators, and assigns, or such others as I, the said
Henry Young Darracott Scott, my executors, administrators, and assigns,
should at any time agree with, and no others, from time to time and
at all times thereafter during the term therein expressed, should and
lawfully might make, use, exercise, and vend, within the United King-

page_text: dom of Great Britain and Ireland, the Channel Islands, and Isle of Man,
an Invention for "AN IMPROVED MODE OF OR PROCESS FOR OBTAINING FERTILIZING
SUBSTANCES," upon the condition (amongst others) that I, the said Henry
Young Darracott Scott, my executors or administrators, by an instrument
in writing under my, or their, or one of their hands and scals, should 5
particularly describe and ascertain the nature of the said Invention,
and in what manner the same was to be performed, and cause the same
to be filed in the Great Seal Patent Office within six calendar months
next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Henry Young Darracott Scott, do 10
hereby declare the nature of my said Invention, and in what manner
the same is to be performed, to be particularly described and ascertained
in and by the following statement (that is to say) :-
The object of this Invention is the manufacture of precipitated
phosphates by the addition to clarified sewage water of impure 15
phosphatic substances, such as those portions of coprolites or bones
which can be dissolved in acid.
In carrying out my Invention I first remove by precipitation from the
sewage water all the suspended matters, and I prefer to use lime alone
for this purpose. I add the lime in sufficient quantity to leave free lime 20
in solution after all the matters admitting of precipitation by this
chemical agent have been removed.
Should sulphate of alumina and iron be employed for this preliminary
precipitation in combination with lime, I add more lime than is sufficient
to combine with the acids of these salts, so that the lime shall always be 25
in excess. The precipitate thus obtained is allowed to subside in a
tank, which I will call tank No. 1, and the precipitate may be dealt
with by methods already known, such as converting it into agricultural
lime or cement, or into charcoal to be used in the final purification of
the effluent, which will be clarified very effectually by the excess of lime 30
used. The excess of lime will also render the deposit very inoffensive.
The effluent from tank No. 1 is now treated with a solution, which is
prepared by digesting (by well known methods) impure phosphatic
substances, such as coprolites in acid, and decanting the liquid obtained
from the intractable residue. The precipitate formed (by the reaction 35
between the free lime in the sewage and the phosphoric acid, &c., in tho

page_text: solution added) is allowed to settlo in tank No. 2, and from this tank
it is removed at intervals, dried and sent into the market as precipitated
phosphate. Or this precipitated phosphate may be converted into super-
phosphate by well known methods.
Tho precipitated phosphate having been freed from the greater portion
of the substances existing in the original material (which are inert as
fertilisers), and having been freed also from the adulterations of worthless
sewage matters will be found to have a very high commercial value as
compared with the sewage precipitated phosphates hitherto sent into the
market, wherewith all the suspended impurities of the sewage, together
with much mineral matter which has been precipitated from the solution
have been mixed up.
The above-named solution obtained by digesting the impure phos-
phatic substances in acid may be added to the effluent from tank No. 1,
either in quantities which leave it still slightly alkaline, or the acid
solution may be added in slight excess. By the latter mode of treatment
the precipitate in tank No. 2 will be freed from the less valuablo
substances, but portions of the fertilizing ingredients will be carried
away in the effluent from tank No. 2, and are to be detained in
tank No. 3 by precipitation with lime added in sufficient quantity to
make the sewage water alkaline. The precipitate thus obtained may be
sold as another quality of phosphate, or may be mixed with the agricul-
tural lime prepared by calcination from the deposit in tank No. 1.
The effluent from the above processes may be finally freed from
organic matter by filtration through charcoal, which may be obtained by
charring the precipitate obtained from tank No. 1. After such charcoal
becomes clogged with impurities, it may likewise be added to the
agricultural lime obtained from other portions of the deposit in the same
tank, or it may be sold independently.
I sometimes add finely divided mineral phosphates to the sewage
water (with the milk of lime) for the first precipitation in tank No. 1.
The calcined residue may have its free lime washed out with clarified
sewage water, which may be employed for the precipitation of a fresh
quantity of sewage, whilst the undissolved residue may be treated with
commercial hydrochloric acid, and the compound may be used to effect
the precipitation of phosphates in tank No. 2.

page_text: L
In cases in which the sewage available is in a concentrated condition,
as in the drainings from urinals or middens I proceed somewhat differently.
In these cases there is no large quantity of inert matter present (as in
sewage from town sewers), and the addition of limo will precipitate
chiefly compounds of high value. On commencing the operation I add
to the liquid in tank 1 so much milk of lime as is sufficient to precipitato
the soluble phosphates in the urine; on arriving at tank No. 2 tho
liquid is treated with a solution of the before-mentioned phosphate, salt,
or phosphoric acid, prepared from phosphatic minerals or other phos-
phates, sufficient to leave the liquid somewhat acid, and the clear liquid 1
after the precipitation and scitlement of a certain amount of tri-
phosphate of lime and nitrogenous matter is then passed on to tank No. 3.
In tank No. 3 it is made to filter upward through a layer of lime in the
_condition of fine powder slaked or unslaked, or the liquid is treated with
excess of lime in any manner which will produce analogous effects (as 1
for instance by stirring the lime with the liquid), and all the free:
phosphoric acid is absorbed. I sometimes add an additional lime tank
(which I will call tank No. 3′), wherein there may be always kept a
great excess of free lime, some portion of this lime being moved to
tank No. 3 at intervals. When the lime in tank No. 3 is so far?
exhausted that very little free lime remains, this compound is moved to
tank No. 1, where fresh portions of sewage are passed through it or
stirred with it. By this means the lime originally placed in tank No. 3ª
is gradually enriched with phosphoric acid and nitrogen compounds, and
becomes at last in tank No. 1 a very valuable manure, which may be
used as a precipitated phosphate, or may be converted into super-
phosphate.
L
In lieu of using lime in tanks No. 3 and No. 3º, I sometimes use
dolomitic lime, I may also add sulphate of magnesia or chloride of
magnesium in tank No. 2 in sufficient proportion to provide the quantity a
of magnesia requisite for the formation of ammoniacal phosphate of

page_text: attention. The liquid will pass off finally saturated with lime, and will
assist in cleansing the sewers which it flows through.
Having now described my Invention of "An Improved Mode of or
Process for Obtaining Fertilizing Substances," and having explained the
manner of carrying the same into effect, I claim as the Invention
secured to me by Letters Patent as aforesaid, manufacturing nitro-
genous phosphates of lime (rich in phosphoric acid) by treating sewago
water (which has been cleansed of its suspended impurities, if any exist),
with a combination of chemical agents consisting of those ingredients of
poor phosphates (such as bones or coprolites), which can be rendered
soluble by acids and an excess of lime, as hercin set forth, which excess
of lime may be added either previously to the removal of the suspended
matters or subsequently.
In witness whereof, I, the said Henry Young Darracott Scott, have
hereunto set my hand and scal, the Twenty-fifth day of July,
in the of L
On those
matters or subsequently.
In witness whereof, I, the said Henry Young Darracott Scott, have
hereunto set my hand and seal, the Twenty-fifth day of July,
in the year of our Lord One thousand eight hundred and seventy-
three.