IMPROVEments in PurifYING PARAFFIN, AND IN' APPARATUS THEREFOR
Year: 1874

page_text: LETTERS PATENT to John Miller and George Miller, both of Aber-
deen, in the County of Aberdeen, North Britain, Manufacturing
Chemists, for the Invention of "IMPROVEments in PurifYING PARAFFIN,
AND IN' APPARATUS THEREFOR."
Scaled the 5th December 1874, and dated the 12th June 1874.
PROVISIONAL SPECIFICATION left by the said John Miller and George
Miller at the Office of the Commissioners of Patents, with their
Petition, on the 12th June 1874.
We, JOHN MILLER and GEORGE MILLER, both of Aberdeen, in the
County of Aberdeen, North Britain, Manufacturing Chemists, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN PURIFYING
PARAFFIN, AND IN APPARATUS THEREFOR," to be as follows, that is to say :-
This Invention has for its object the purifying of paraffin in a simple,
efficacious, and economical manner, and relates to two stages of the
purifying operations. In the first stage oils and constituents of too
fusible a nature are removed from the paraffin wax by a draining

page_text: process, aided by improved arrangements and apparatus, and in the
second stage color is removed by means of calcined sulphate of
magnesia.
In carrying out the Invention the crude paraffin wax is melted,
and, coarse impurities having been separated from it by settling, is run
upon a stratum of hot water in long shallow troughs. In the troughs
there are placed portable horizontal frames covered with cloth, and
the stratum of hot water is made of a depth just to cover these
frames. The hot water may be allowed to cool of itself; it is however
preferred to displace it with cold water to induce the rapid solidifi-
cation of the wax. The cold water is next withdrawn, whereupon
the wax settles down upon the cloth, and afterwards hot water is
again admitted to the trough, and passed through in a continuous
stream, which is regulated in depth to leave a thin but definite air
and steam space between it and the under side of the cloth. The
temperature of the water is regulated so that whilst the paraffin wax
is just softened the penetrating action of the steam or vapor beneath
melts out the oil and weaker paraffins present. Small globules of
these continue to ooze out from the wax and drop into the water,
whereon they float off to an oil trap at the outlet until the wax
acquires a vascular condition, and becomes more uniform in its melting
point.
.
After the paraffin wax has been purified from oils or weaker paraffins
in the manner herein-before described, or otherwise, it is again melted,
and there is stirred into it a quantity of sulphate of magnesia previously
calcined and reduced to powder. This quickly absorbs the darker
coloring matters present, and leaves merely a yellowish tint which
can be removed by well-known means, after which the last traces of
color are removed by means of animal charcoal, or by again treating
the wax with a quantity of calcined sulphate of magnesia. When
the discolored salt has settled it is run from the mixer into hot water
wherein it quickly dissolves, the adhering wax and coloring matters
rising to the surface. The clear solution is drawn off and allowed to
cool and crystalise, after which the crystals can be recalcined for using
over again.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Miller and George Miller in the Great Scal
Patent Office on the 9th December 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JOHN
MILLER and GEORGE MILLER, both of Aberdeen, in the County of.
Aberdeen, North Britain, Manufacturing Chemists, send greeting..
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twelfth day of June, in the year of
our Lord One thousand eight hundred and seventy-four, in the thirty-
seventh year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto us, the said John Miller and George Miller,
Her special licence that we, the said John Miller and George Miller, our
executors, administrators, and assigns, or such others as we, the said
John Miller and George Miller, our 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 Kingdom of Great Britain and Ireland, the Channel Islands,
and Isle of Man, an Invention for "IMPROVEMENTS IN PURIFYING PARAFFfin,
AND IN APPARATUS THEREFOR," upon the condition (amongst others) that
we, the said John Miller and George Miller, our executors or admini-
strators, by an instrument in writing under our, or their, or one of.
their hands and seals, should 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 we, the said John Miller and George Miller,
do hereby declare the nature of our said Invention, and in what
manner the same is to be performed, to be particularly described and
ascertained in and by the following statement in writing, that is to
say:―
Our said Invention has for its object the purifying of paraffin in a
simple, efficacious, and economical manner, and relates to two stages
of the purifying operations. In the first stage, oils and constituents

page_text: of too fusible a nature are removed from the paraffin wax by a sweating
and draining process, aided by improved arrangements and apparatus ;
and in the second stage color is removed by means of calcined sulphate
of magnesia.
In practically carrying out our said Invention the crude paraffin
wax is melted and its coarser impurities are separated from it by
settling. It is then run upon à stratum of hot water contained in
shallow wooden troughs which may conveniently be 25 to 30 feet
long, and 24 to 30 inches wide. In these troughs are placed portable
horizontal wire frames covered with cloth, or with coir matting, or
other suitable permeable material, and made either flat, or with lọngi-
“tudinal angular ridges. We find the ridged frames preferable, and
make the ridges 7 to 8 inches apart, and with the sides inclined at
or about 45 degrees to the horizontal. A half-inch malleable iron tube
with perforations along its under side is placed beneath and within
each ridge. The hot water is filled into the trough to such a depth
as to merely cover the ridges of the frames, and after the wax is
run upon the water both may be allowed to cool of themselves. We
prefer however to displace the warm with cold water to induce the
more rapid solidification of the wax. The cold water is next withdrawn,
whereupon the wax settles down in one large cake and rests on the
ridges of the frames. Hot water is then admitted to the iron tubes,
and passing for the greater part through the perforations plays right
and left on the bottom of the trough. The heat thereby evolved
softens the slicet of wax above, and the wax sinks into the hollows
between the ridges, and may then be cut longitudinally midway
between the ridges so as to form. long bars or strips of wax lying
upon the ridges and partly down their sides. The temperature of the
water flowing through the tubes and along the bottom of the trough
is regulated so that whilst the paraffin wax is no more than softened
the penetrating action of the steam beneath melts or sweats out the
oil and weaker paraffins present. . Small globules of these containing
coloring matters from the wax continue to ooze out from it and drop.
into the water, whercon they float to an oil trap at the outlet. This
operation is continued until the wax assumes a porous or spongy
condition, and becomes more uniform in its melting point. Six to
eight hours, according to the quality of the wax operated on, we find
to be sufficient for the process:

page_text: The long strips of drained wax are to be removed from the frames
whilst still warm and remelted, either for an immediate repetition of
the process, or for further treatment, as herein-after described. Or the
wax may be thrown into cold water, and when sufficiently hardened be
stored for further treatment at another time.
We find it in most cases useful to remelt and sweat the wax a
second time, after which it is in a fit condition for being treated
with either spirit or acid, as usual, or with calcined sulphate of
magnesia. The wax having been remelted and settled in order to
free it as much as possible from water and any adliering impuritics,
we stir into it from 2 to 5 per centum by weight of sulphate of
magnesia previously calcined and reduced to powder. This sulphate
of magnesia quickly absorbs many of the impurities which the sweating
process failed to remove and carries them to the bottom. The clear
supernatant wax after being transferred to another vessel is treated
a second time with sulphate of magnesia, from 5 to 10 per centum
being now stirred in. This clarifies the wax still further, leaving only
a slight greenish tint which can be altogether removed by spirit and
pressure, or by other well-known means.
The semi-transparent brilliancy hitherto given to paraffin wax by a
liberal use of animal charcoal as a final treatment may be obtained
by a third treatment with 5 to 10 per centum of sulphate of magnesia.
The discolored magnesia from either the earlier or later treatments is
run from the mixer into hot water, wherein it quickly dissolves. The
adhering wax and coloring matters rise to the surface and are either
skimmed of while warm, or.
r. allowed to cool and solidify. The clear
solution beneath is drawn off, and allowed to cool and crystallise,
after which the crystals may be calcined and reduced to powder for
reuse.
Having thus particularly described our said Invention, and the
manner of performing the same, we have to state that we do not
restrict ourselves to the precise details herein-before described, and
that we do not claim as new the mere draining of softened or warmed
paraffin wax; but that what we believe to be new and original, and
claim as the Invention secured to us by the herein-before in part recited
Letters Patent is,―
1. The purifying of paraffin bv an improved steaming and draining

page_text: process, and by means of improved apparatus substantially such as are
herein-before described.
2. The decolorising or purifying of paraffin by means of calcined
sulphate of magnesia applied substantially in the manner herein-before
described.
In witness whereof, wc, the said John Miller and George Miller,
have hereunto set our hands and seals, this Fifth day of
December, in the year of our Lord One thousand cight hundred
and seventy-four.