IMPROVEMENTS IN THE PURIFICATION OF WATER AND OTHER FLUIDS."
Year: 1875

page_text: LETTERS PATENT to Thomas Spencer, of No. 32, Euston Square,
London, Analytical and Consulting Chemist, for the Invention of
"IMPROVEMENTS IN THE PURIFICATION OF WATER AND OTHER FLUIDS."
PROVISIONAL SPECIFICATION left by the said Thomas Spencer at the
Office of the Commissioners of Patents, with his Petition, on the
15th April 1875.
I, THOMAS SPENCER, of No. 32, Euston Square, London, Analytical
and Consulting Chemist, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE PURIFICATION OF WATER AND OTHER
FLUIDS," to be as follows:-
This Invention consists in the production of porous magnetic blocks
of any desired shape for the purification of water and other fluids, the
said blocks being chiefly composed of ferrugenous magnetic oxide in
mixture with a small proportion of carbon. In its ordinary state this
oxide is granular, like coarse gunpowder, and its grains are almost

page_text: equally friable and reducible to fine powder. This drawback has
hitherto prevented this most desirable oxide from being used for light
portable filters, suited for travelling or field or camp use. By continuous
movement the attrition of its loose grains on each other causes the
whole to be reduced into fine powder, which prevents filtration. To
overcome this difficulty I have devised methods of forming this granular
oxide into solid but porous blocks, to effect which I take this or any
other ferruginous oxide and mix the same with about a fourth of its
weight of ordinary flour, and with water, to which yeast is added, bring
the whole to the consistency of dough. It is then put into metallic or
carthenware moulds and subjected to the heat of a baking oven, by
which it acquires the porosity of bread. The magnetic blocks thus
formed are put into another oven (the opening of which being luted to
exclude air), where they are subjected to a dull red heat and allowed to
cool before they are withdrawn. Such are the essential features of my
said Invention, further details of which will be given in the Final
Specification.
The means employed are also applicable to the consolidation of any
ferruginous oxide or ferruginous refuse, and applicable to similar
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Thomas Spencer in the Great Seal Patent Office on
the 13th October 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
SPENCER, of No. 32, Euston Square, London, Analytical and Consulting
Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fifteenth day of April, in the year of
our Lord One thousand eight hundred and seventy-five, in the thirty-
eighth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Thomas Spencer, Her special licence, that
I, tho said Thomas Spencer, my executors, administrators, and assigns,
or such others as I, the said Thomas Spencer, my executors, admını-
strators, and assigns, should at any time agree with and no others,
from time to time and at all times thereafter during the term therein

page_text: expressed, should and lawfully might make, use, exercise, and vend,
within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN THE PURIFI-
CATION OF WATER AND OTHER FLUIDS," upon the condition (amongst others)
that I, the said Thomas Spencer, my executors or administrators, by an
instrument in writing undor my, or their, or one of their hands and seals,
should particularly describe and ascertain the nature of the said Inven-
tion, 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 Thomas Spencer, do 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:-
The said Invention consists in the production of porous magnetic
blocks of any desired size or shape for the purification of wator or other
fluids, the said blocks being chicfly composed of a granular ferruginous
substance first made known, introduced, and patented by me for the
above purposes, and since then known as magnetic carbide. This
substance as now in use is chiefly composed of ferroso-ferric oxide in
combination with about as much carbon as goes to the formation of
ordinary steel. The quantity of carbon absorbed in its preparation
greatly depends on the nature of the original ore. The carbon however
is not essential to the purifying qualities of the carbide, which essentially
belong to the ferruginous oxide, the carbon only being added to give
hardness and contribute to its porosity. This substance as described in
my original Patent on this subject is usually manufactured for use in a
state of granulation similar to coarse grained gunpowder, in which state
I apply it for household and water works filters. Its state of granulation
however has operated hitherto to prevent its use for lighter portable
filters, such as are suitable for travellers and others moving from place
to place. The drawback to its use for this class of filters arises from
the attrition of its friable grains in the course of carriage, by which they
are liable to become reduced into a state of fine powder, which thereby
operates to retard the passage of water. To overcome this difficulty I
have devised the following method of combining this granular magnetic
material into solid but porous blocks, by which means the above

page_text: objection is remedied. The mode of their production is varied however
to meet the chemical or mechanical conditions of the ferruginous
material which is required to be aggregated together, which modes I shall
now describe.-1 prefer at the commencement to have the magnetic
carbide or ferruginous oxides which I may find it convenient to use in each
case reduced to a state of fine grained powder. With this powder I mix
about one-fourth of its weight of ordinary flour of any quality or
texture, and to this add as much water as will bring the mixture to the
state of ordinary dough. The doughy matter is then put into metallic
or carthenware moulds of any required shape or size. These moulds
and their contents are then subjected to a temperature of a baking or
other similar oven for a period as long as serves to bake bread. Whilst
in the-oven the well-known peculiar powers of the magnetic carbide to
convert organic matter into carbonic acid is exercised on the particles
of flour which is in mixture with the said ferruginous material, by
which means the mass is rendered as porous as bread is by yeast.
When the blocks are required to be very porous however I use the
above-named quantity of flour as the maximum, but when intended to
be less so a proportionately less quantity of flour is used. In some
cases a fifth or a sixth of the weight of the oxide used is found to be
sufficient.
'As at the termination of the first stage of heating the magnetic blocks
are not sufficiently hardened they are then removed to a hotter oven or
furnace, and there are made thoroughly dry When the moisture is
fully driven off in this oven and the flour or other carbonaceous matter
is carbonized the opening of the said oven is closed and luted to exclude
air in the manner practised with lighting gas retorts. This oven is then
brought to a higher temperature of about 700 degrees Fahrenheit, being
as much as is sufficient to bring the magnetic blocks to a dull red, in
which state they are kept from three to four hours. Larger blocks
however require to be kept in the oven an hour or two longer They
are then under all circumstances suffered to cool gradually before they
are withdrawn or exposed to air.
When larger blocks or slabs are required, and increased coherence of
the magnetic material comes thereby necessary, I introduce into the
primary ferruginous and flour mixture from seven to ten per cent. in
weight of fine sand or aluminous silt before I add the necessary water

page_text: to the same, but when the slabs or blocks are required to be larger
than ordinary I then find it necessary to add a little more than the above
quantity of sand along with about one, or one and a half per cent. of
carbonate of soda to bind the mass more firmly together by a semi-fusion
of the sand while in the second oven.
Similar magnetic filtering blocks can also be made by means of any
ferruginous oxide reduced to granulation, such as that directly obtained
from crushed hematite, or from raw iron ore, or ferruginous hydrate, or
iron pyritic, or other ferruginous refuse material of any sort, including
filings of iron, cach in mixture with flour as above described, or equally
with any other easily reduced carbonaceous substance, such as bruised
coke, sawdust, sugar, treacle, tar, or bitumen, and then subjecting the
same to heat in the manner described. I prefer however to use magnetic
carbide in powder when the same is available, as it entails the least
trouble, and produces the better results.
In instances when the so-called magnetic carbide or magnetic oxide
is not used and other ferruginous matters substituted it is necessary to
mix a little yeast with the flour in the first mixture to render the
resulting blocks sufficiently porous to allow water to pass freely on their
ultimate removal from the second oven or furnace, but in cases where
iron ore other than magnetic oxide is used a more lengthened heating
is necessary in the final oven in order to thoroughly magnetize any
peroxide of iron or metallic iron which may be used in the said mixture
for the production of the said magnetic filtering blocks or slabs
irrespective of their shape or size, and which constitute my aforesaid
Invention.
In witness whereof. I. the said Thomas Spencer. have hereunto