IMPROVEMENTS IN OBTAINING ANILINE
Year: 1875

page_text: LETTERS PATENT to Justus Wolff, of Wyke, near Bradford, Consulting
and Engineering Chemist, and William Ascroft Byrom, of Wigan,
Solicitor, for the Invention of "IMPROVEMENTS IN OBTAINING ANILINE
PROVISIONAL SPECIFICATION left by the said Justus Wolff and
William Ascroft Byrom at the Office of the Commissioners of
Patents, with their Petition, on the 5th July 1875.
We, JUSTUS WOLFF, of Wyke, near Bradford, Consulting and
Engineering Chemist, and WILLIAM ASCROFT BYROM, of Wigan,
Solicitor, do hereby declare the nature of our said Invention for "Iм-
PROVEMENTS IN OBTAINING ANILINE, AND IN THE EMPLOYMENT OF THE SAME OR OF
COMPOUNDS THEREOF," to be as follows:-
A great deal of aniline is wasted by discharging the salted aniline
waters, and this Invention especially relates to the recovery and using
of aniline contained therein. For this purpose we add whilst stirring to
the aniline waters, either salted or not, but rendered as nearly neutral

page_text: as possible, a solution of sulphate of copper or other suitable copper or
other metallic salt as long as this solution produces a precipitate in the
water containing aniline. After precipitation the result is filtered off and
the liquid remaining is separated as much as possible from the precipitate,
either by draining or filtering, or by slight pressure. The product or paste
thus resulting is then mixed with an equivalent quantity of caustic
soda (dry or contained in a strong or weak solution) and the thus
liberated aniline with the water contained in the precipitate is distilled
over, and distillation may be carried on nearly or quite to dryness of the
remainder or residue. The thus yielded distillate is then salted, and
after settling the aniline is separated from the water. The remainder or
residue contained in the still or retort is treated with water in order to
dissolve the sulphate of soda or other soluble salts, and the remaining
oxide of copper is treated with the equivalent quantity of sulphuric or
other suitable acid and with sufficient water to effect the solution of the
resulting salts. The solution is then filtered and cooled, whereby
sulphate or other salt of copper is obtained, and the oxide of copper is
thus recovered.
The precipitate obtained from the treatment of the waste water with
salts of copper can be used directly for printing aniline colors, such as
black and gray, grayish blue, &c., &c., by mixing it with the corre-
sponding quantity of hydrochloric acid and of chlorate of potash,
together with boiled starch or with other thickening materials, printing
and then oxidizing for about from 12 to 24 hours, and afterwards passing
the textile materials or fabrics through a sour hot solution of bichromate
of potassium, then washing in a warm soda bath, finally in water, and
subsequently drying. Of course these rules for printing with the said.
materials can be altered; as for instance, the paste may be mixed with
the thickening material, either with or without any addition of free
acid (hydrochloric or any other suitable acid), printed, dried, and the
goods directly passed through a sour hot solution of bichromate of
potassium, washed with or without soda, and dried.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent
filed by the said Justus Wolff and William Ascroft Byrom in the
Great Seal Patent Office on the 5th January 1876.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JUSTUS
WOLFF, of Wyke, near Bradford, Consulting and Engineering Chemist,
and WILLIAM ASOROFT BYROM, of Wigan, Solicitor, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fifth day of July, in the year of
our Lord One thousand eight hundred and seventy-five, in the 39th
year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto us, the said Justus Wolff and William Ascroft Byrom,
Her special license that we, the said Justus Wolff and William
Ascroft Byrom, our executors, administrators, and assigns, or such
others as we, the said Justus Wolff and William Ascroft Byrom, our
executors, administrators, or 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 OBTAINING ANILINE, AND IN THE EMPLOYMENT OF THE SAME OR OF COMPOUNDS
THEREOF," upon the condition (amongst others) that we, the said Justus
Wolff and William Ascroft Byrom, our exccutors or administrators, by an
instrument in writing under our hands and seals, or under the hand and
scal of one of us, should particularly describe and ascertain the nature
of the said Invention, and in what manner the same was to be per-
formed, and cause the same to be filed in the Great Seal Patent Offico
within six calendar months next and immediately after the date of the
said Letters Patent.
NOW KNOW YE, that we, the said Justus Wolff and William Ascroft
Byrom, 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, that is to say :-
This Invention relates to the recovery and use of aniline contained in
aniline waste waters. For this purpose we add whilst stirring to the
aniline waters, or what are called waste waters, either salted or not, but

page_text: rendered as nearly neutral as possible, a solution of sulphate of copper,
or other suitable salt of copper, or other metallic salt, so long as this
solution or solutions produces a precipitate in the water or solution
containing aniline. After precipitation the result is filtered off and the
liquid remaining is separated as much as possible from the precipitate
either by draining or filtering, or by slight pressure, as is well under-
stood. The product or paste thus resulting is then mixed with an
equivalent quantity of caustic soda or other suitable alkali or alkalino
earth, dry or contained in strong or weak solution, and the thus liberated
aniline with the water contained in the precipitate is distilled over, and
distillation may be carried on nearly or quite to dryness of the remainder
or residue. The thus yielded distillate is then salted, and after settling
the aniline is separated from the water. The remainder or residue
contained in the still or retort is treated with water in order to dissolve
the sulphate of soda or other soluble salts, and the remaining oxide of
copper is treated with the equivalent quantity of sulphuric or other
suitable acid, and with sufficient water to effect tho solution of the
resulting salts. The solution is then filtered and cooled, whereby
sulphate or other salt of copper is obtained, and the oxide of copper is
thus recovered.
The precipitate obtained from the treatment of the waste water with
salts of copper can be used directly for printing aniline colors, such as
black and gray, grayish blue, etc., etc., by mixing it with the corre
sponding quantity of hydrochloric acid and of chlorate of potash,
together with boiled starch or with other thickening materials, printing,
and then oxidizing for about from 12 to 24 hours, and afterwards passing
the textile materials or fabrics through a sour hot solution of bichromate
of potassium, then washing in a warm soda bath, finally in water, and
subsequently drying. Of course these rules for printing with the said
material can be altered, as for instance, the paste may be mixed with
the thickening material, either with or without any addition of free
acid, hydrochloric or other suitable acid, printed, dried, and the goods
directly passed through a sour hot solution of bichromate of potassium,
washed with or without soda, and dried.
Having now described and particularly ascertained the nature of our
said Invention, and the manner in which the same is or may be used
or carried into effect, we would observe in conclusion that what we
consider to be novel and original, and therefore claim as the Inven-

page_text: tion secured to us by the herein-before in part recited Letters Patent
is,―
First. Effecting the recovery of aniline from solutions or waste waters
containing the same by firstly adding thereto a soluble metallic salt or
compound capable of combining therewith and of producing an insoluble
compound or precipitate, such metallic salt being by preference a salt of
copper, and then effecting the separation of the aniline therefrom by the
employment of an alkali, or of an alkaline earth, and by subsequent
distillation.
Second. The employment and use of the insoluble compound or
precipitate, obtained as before mentioned, for the purposes of printing
upon woven fabrics, more especially upon cotton fabrics.
In witness whereof, we, the said Justus Wolff and William Ascroft
Byrom, have to this our Specification set our hands and seals,
the Fourth day of January, One thousand eight hundred and
seventy-six.