IMPROVEMENTS IN THE MANUFACTURE OF FILTERS OR FILTERING MATERIAL
Year: 1878

page_text: LETTERS PATENT to William White, of Chancery Lane, in the County of
Middlesex, for the Invention of "IMPROVEMENTS IN THE MANUFACTURE OF
FILTERS OR FILTERING MATERIAL."
Sealed the 14th March 1879, and dated the 21st September 1878.
PROVISIONAL SPECIFICATION left by the said William White at the Office
of the Commissioners of Patents on the 21st September 1878.
WILLIAM WHITE, of Chancery Lane, in the County of Middlesex.
MENTS IN THE MANUFACTURE OF FILTERS OR FILTERING MATERIAL."
"IMPROVE-
I
Water is commonly filtered through charcoal, or combinations of charcoal with
clay or silica, or through spongy iron.
'
The material I propose to employ for filtration is oxide of iron with charcoal in
excess of what is requisite for deoxidisation, and sufficient alumina to confer
tenacity without unduly affecting porosity.
Bog ochre, such as is found in the North of Ireland, with the addition of clay,
soft iron ores, such as exist in Northamptonshire and Lincolnshire, with the
addition of carbon, and crushed pyrites' cinder, with the addition of clay and carbon,
furnish cheap and convenient constituents of the material I employ and which is
prepared for use by calcination in closed retorts.
Out of this material I also form vessels, cups, basins, bottles, slabs, tanks after
the manner of ordinary porous ware, but firing the same in a close oven or retort
and allow the water or other liquid to be purified to percolate through the walls of
the vessel from within or from without, that is to say, the liquid to be purified is
either put into the vessel and allowed to percolate through it, or the vessel is
plunged into the liquid and the liquid allowed to percolate into it. This capacity
for reverse action is a means whereby the filter ware may be washed and restored
to purity.
Such vessels may also be cleansed by boiling or still more thoroughly by
re-burning.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William White in the Great Seal Patent Office on the 21st March
1879.
WILLIAM WHITE, of Chancery Lane, in the County of Middlesex.
MENTS IN THE MANUFACTURE OF FILTERS OR FILTERING MATERIAL."
"IMPROVE
Heretofore water has been commonly filtered through charcoal, or combinations
of charcoal with clay or silica, or through spongy iron.
According to my Invention the material I propose to employ consists of oxide
of iron with charcoal in excess of what is requisite for de-oxidisation, and sufficient
alumina to confer tenacity without unduly affecting the porosity of the resulting
material.
Bog ochre, such as is found in the North of Ireland, with the addition of clay,
soft iron ores, such as exist in Northamptonshire and Lincolnshire, with the
addition of carbon, and crushed pyrites' cinder, with the addition of clay and carbon,
'furnish cheap and convenient constituents of the material I employ.
These materials I prepare by thoroughly amalgamating them into a homogeneous
mass of a somewhat similar character to potters' clay, which I form into slabs or
blocks and afterwards calcine the same in closed retorts or kilns to prevent the loss
by combustion of the carbon constituent. These slabs or other forms of filtering
material may be mounted or used in any convenient manner in lieu of the ordinary
filtering material.
Out of this material I also form vessels, cups, basins, bottles, tanks after the
manner of ordinary porous ware, but firing the same in a close oven, retort, or kiln,
and I allow or cause the water or other liquid to be purified to percolate through
the walls of the vessel from within outwards or from without inwards, that is to
say, the liquid to be purified is either put into the vessel and allowed to percot e
through it, or the vessel is plunged into the liquid and the liquid allowed to
percolate into it. This capacity for reverse action is a means whereby the filter
ware may be washed and restored to purity.
Such vessels may also be cleansed by boiling or still more thoroughly by re-
burning in closed retorts or kilns.
The following is an example of one method of carrying my Invention into
effect; I mix five parts by weight of artificial red oxide of iron with about two
parts by weight of powdered charcoal and an equal weight of potters' clay; I well
work these materials together and then shape the clay-like material into the form
required, after which I calcine the same in a closed retort or kiln.
The natural ores of iron are associated with more or less alumina and silica, and
in some cases with carbon, and when using natural ores of iron in the manufacture
of my improved filtering material it will be necessary to analyse the same, in order
to ascertain the proportions of their constituents and to regulate the quantity of
alumina and carbon to be added thereto which should be in somewhat of the pro-
portions above given.
The carbon is required to deoxidise the iron ore and clay to hold the material
together without too great interference with its porosity.
Having thus described the nature of my said Invention, and one mode in which
the same may be carried into effect, I would have it understood that what I claim
is the employment of a combination of oxide of iron; carbon, and alumina well

page_text: worked together and calcined in a close retort or kiln to produce any desired form
of filter or filtering material, substantially as herein described.
In witness whereof, I, the said William White, have hereunto set my hand
and seal, this Twentieth day of March, in the year of our Lord One thousand
eight hundred and seventy-nine.
WILLIAM WHITE. (L.S.)