IMPROVEMENTS IN TREATING THE RESIDUUM OR PRECIPITATE OBTAINED IN THE PURIFICATION OF SEWAGE
Year: 1877

page_text: LETTERS PATENT to Joe Frost, of Huddersfield, in the County of York, Manu-
facturing Chemist, for the Invention of "IMPROVEMENTS IN TREATING THE
RESIDUUM OR PRECIPITATE OBTAINED IN THE PURIFICATION OF SEWAGE."
.
Sealed the 15th February 1878, and dated the 18th August 1877.
"
PROVISIONAL SPECIFICATION left by the said Joe Frost at the Office of
the Commissioners of Patents on the 18th August 1877.
JOE FROST, of Huddersfield, in the County of York, Manufacturing Chemist.
IMPROVEMENTS IN TREATING THE RESIDUUM OR PRECIPITATE OBTAINED IN THE
PURIFICATION OF SEWAGE."
My Invention consists in treating the residues in such a manner as to render
the same fit for use a second or any number of times for the same purpose, namely,
that of purifying sewage and other foul waters. Thus when metallic salts, for
instance, have been used, I recover or reconvert them to their original condition,
and also effect the recovery of the ammonia.
My treatment consists in burning the residues to such an extent as will suffice to
reduce the compounds to their original condition, and my mode of procedure is as
follows:-I take the residue and drain off or evaporate the principal portion of the
water or liquid, and when about the consistence of clay, I make or mould the same
into pieces or lumps of any shape most convenient; these I then take and dry
further to get rid of as much moisture as possible. I then place the dried lumps in
a kiln or furnace along with coal or other carbonaceous matter, and then raise the
same to a red or white heat or temperature sufficiently high to bring about the
change required.
The gases generated by the heated residue are conveyed to suitable apparatus so
that the ammonia may be recovered in the form of sulphate or other salt of the
same, and the other gases are conveyed to a chimney, or may be burnt to assist in
drving the residuum.

page_text: When the required change takes place, the lime in the residue, in the condition of
carbonate, or the lime in combination with the organic matter, is freed from its com-
binations and converted into simple lime by the reducing action of the carbon at a
high temperature, or by the action of heat alone. If sufficient carbon is not present
in the residuum, I add the same thereto. The sulphate of lime, also becomes changed
by the same means into the sulphides or oxi-sulphides of lime which, when in presence
of iron or its oxides, becomes changed into lime and the sulphides of iron.
When the residue is from a process of purifying where iron compounds have been
chiefly used, it is converted by the above process into carbon and metallic iron or
oxide or sulphide of the same.
When the barium compounds have been used, as specified in my Patent, dated
August 26th, 1876, No. 3365, the barium sulphate is converted by the same process
into barium sulphide, or the oxide when an excess of iron oxide is present and
processess the same properties as the barium compounds first prepared.
The carbon of the organic matter not used up in the process is chiefly animal
carbon, and is in the most suitable condition for deodorizing or decolorizing sewage
or other foul waters. Or I mix the residues with a quantity of fresh slaked lime
to make it more alkaline, and submit the whole to the foregoing treatment. By
mixing more lime I obtain a larger quantity of the nitrogen existing in the residue
in the condition of ammonia. If necessary, I mix a quantity of soda to obtain
more ammonia, when the residues are rich in nitrogen. Or I mix the residue with
a quantity of per or proto oxide of iron, or waste scrap iron, or other metallic oxide
capable of uniting with the sulphur; I then submit these to the heating process.
I may mix with the residue, waste lime or sulphate of lime from various manu-
factures, or with clay, in some cases, to hold together the residue.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Joe Frost in the Great Seal Patent Office on the 18th February
1878.
"
-
JOE FROST, of Huddersfield, in the County of York, Manufacturing Chemist.
IMPROVEMENTS IN TREATING THE RESIDUUM OR PRECIPITATE OBTAINED IN THE
PURIFICATION OF SEWAGE."
'My Invention consists in treating the residues in such a manner as to render the
same fit for use a second or any number of times for the same purpose, viz., that of
purifying sewage and other foul waters.. Thus when metallic or other compounds
have been used, my object is to recover or convert them to their original condition,
and also to recover the ammonia.
My treatment consists in burning the residues to such an extent that the com-
pounds are reduced thereby to their original condition, or to such a state that they
are fit to use over again, the following being the usual mode of procedure :-I take
the residues from the purification of sewage and drain off the greater part of the
water or liquid, or I may evaporate the same by any suitable means; and when the
residue has reached about the consistence of clay, I make or mould the same into
pieces or blocks, which I subject to further drying to get rid of as much moisture
as possible. I then place the dried masses in a kiln or furnace with or without
coal or other carbonaceous matter.. I then raise the same to a red or white heat,
or to a temperature sufficiently high to bring about the change required.
The heating may be carried on in a reverbatory or other furnace or in ovens, and
at the same time convey the gases from the heated residues to suitable apparatus
for the purpose of recovering the ammonia in the condition of sulphate of ammonia,
or other salt of ammonia. The gases may be burnt, and the heat generated thereby
may be utilized in drying other residue.
When heated to a sufficient extent, the lime contained in the residue, originally
in the condition of carbonate of lime or in combination with organic matter, is
converted or reduced to lime by the action of carbon at a high temperature, the heat
alone operating to effect this change to a great extent. If sufficient carbon is not
present in the residue, I add the same thereto. The sulphate of lime which may be
present becomes converted into the sulphide or oxy-sulphide of lime, which, when
in the presence of iron or its oxides, becomes converted into iron sulphide and
lime.
a
When the residuum is from a process of purifying water or sewage where iron
compounds have been chiefly used, the residue is converted by the heating process
into carbon, metallic iron, together with the oxide and sulphide of iron; all these
being in a condition suitable for treating sewage or for making into compounds well
known for that purpose.
When compounds have been used, such as are described in the Specification of
previous Letters Patent granted to me, August 26th, 1876, No. 3365, the barium
sulphate or carbonate is converted by the herein described process into barium
sulphide or barium oxide, when an excess of iron oxide is present, and these possess
the same properties as barium does when first used.
The carbon of the organic matter not used up in the process chiefly consists
of animal carbon, and this is in the most suitable condition for deodorizing or
decolorizing sewage or other foul waters. I may also mix the residues with a
quantity of new slaked lime to make it more alkaline, and then submit the whole
to the treatment already described; by mixing with more lime I obtain a larger
quantity of nitrogen existing in the residue in the form of ammonia which I recover.
If necessary, I mix a quantity of soda with the residues to obtain more ammonia
when the residues are rich in nitrogen. Or I may mix the residue with a quantity
of per or proto oxide of iron, or what are known as the natural oxides, such as the
ores or the spent oxides from various sources, or waste scrap iron, or other metals

page_text: or oxides which are capable of uniting with sulphur; these I grind or work together
in a machine with the oxides of iron or other oxides specified to mak a more
intimate mixture, and then I make these mixtures into any required form suitable
for undergoing the heating process. Or I mix with the residue waste lime or
sulphate of lime from various manufactures, or with clay, in some cases, to hold
together the residues.
The following are the advantages of this method:-
Firstly. That the difficulty of getting rid of the enormous amount of residuum
which must accumulate at sewage works is entirely overcome.
Secondly. Its value for use again is more than could possibly be obtained by
making into manure.
".
Thirdly. The principal fertilizing ingredients in the residue can all be recovered
in a more valuable condition, viz., the salts of ammonia.
Fourthly. It can be used over and over again until it is richer in phosphates of
lime, so that it may be valuable as a manure.
Fifthly. It will enable anyone to use materials far more effective for the purifi-
cation of sewage, which has hitherto been too costly, as they are recovered and used
again, particularly where iron compounds have been used, which can all be recovered in
the condition of oxide or sulphide of iron, and then can be converted into the sulphates
by means of sulphuric acid or other salts by the use of corresponding acids; or by
the exposure to the air of sulphide of iron, which will then become oxidised to the
sulphates of iron, and will then be ready for use again.
What I claim is the complete burning of the residue from any process of sewage
purification whatever, to produce any of the compounds originally used for the
purpose or to bring about the changes, substantially as herein described.
In witness whereof, I, the said Joe Frost, have hereunto set my hand and
seal, this Fifteenth day of February, in the year of our Lord One thousand
eight hundred and seventy-eight.
TAB
JOE FROST. (L.S.)